Weld Management Information for large scale weld projects.
Ship Yard, Oil Platforms, Pipe Appications, or building Construction
Equipment, most of the MIG and flux cored weld issues are due to lack of process control expertise.
Scroll down to find out how MIG - Flux Cored weld process control and best practice, annualy saved
a ship yard and and oil company millions of dolllars.
the too common global lack of management interest in the establishment
of MIG and FCAW flux cored best practices and weld process controls,
there should always be concern for weld
failures and exitement about the potential for extraordinary weld cost savings.
It takes much more than "welder skills" to consistently produce optimum MIG - Flux Cored weld quality at the lowest weld costs.
2001: YOU MAY NOT WANT TO ASK THE WELD DECISION MAKERS WELD PROCESS QUESTIONS.
most global ship and large construction projects, either the flux cored and MIG process will typically account
for the majority of welds. If at these projects you could get all the weld
managers, engineers, technicians, trainers, QA personnel, and welders together
in a classroom, and ask them some fundamental MIG and flux cored questions about the required best weld practices and weld process
controls, the mostly diverse, incorrect answers, and the evident lack of weld process contro; - best practice knowlege would be a surprise
to anyone with an ounce of engineering common sense. This scenario would have
applied in 1975, and it still applies today in 2015.
As we head into 2015, weld projects and numerous applications are being introduced that are more complex or larger in scope and consistently attaining, cost effective code quality welds is not being made easier with many of the recently introduced heat sensitive, complex alloys such as the duplex, inconel and high strength aluminum. The majority of welds at large projects will be made with either MIG or flux cored and for the five decades I have been involved with weld processes. I find it completely illogical that the responsible weld management, engineers and supervisors would not be Process Control - Best Weld Practice experts, especially as these two weld processes account daily for more than 80% of the world's welds.
From those robot MIG welds in the auto - truck or the manual MIG welds in the Caterpilla Equip plants, to the flux cored welds made on USA built oil platforms, or on the Chinese, Olympic Birds Nest Stadium above, you will find that the general lack of weld process control - best practice expertise has daily, serious dollar cost consequences that may result from weld quality, weld clean up, weld rework, weld rejects, poor productivity, and of course the extensive concerns for product weld failures and liability.
In the common "global weld manufacturing environment" today we have countries like China successfully bidding on global pipe line projects or on American Bridge Contracts. The Chinese (Indian - Mexican - Korean - Brazil - Eastern European) companies can use the same weld equipment, processes and consumables, and the majority of the companies will typically get subsidies from their government which will be an addition advantage that they can add to utilizing workers and welders that may be paid less than $5 hour.
For industrial nations to compete with the many countries that have little concern for labor costs, companie's need weld decision makers that have the ability to take full ownership of the weld equipment - process and consumable that are selected and utilized. Its logical that the managers and engineers responsible would ensure that their projects are manned by weld personnel that have recieved the Process Control - Best Practice training so they can daily attain consistent, optimum weld quality and productivity always at the lowest possible weld costs.
Unfortunately as the owners and the construction managers of the oil platform
below found out, the lack of front office and shop floor weld process control - best practice expertise had grave consequences.
In the last three five decades, I have been in over 1000 weld shops in 13 countries, and I would say that in the majority of weld departments, the managers, engineers and supervisors that I met were not in control of their costs or they had a "hands off" approach to welding. In this enviroment it should be no surprise to find that like a poorly run ship "the crew was running the ship".
When the prime weld decision makers don't take "full ownership" of the common weld equipment utilized, it typically means these individuals will rely on the advice from weld distributor salesmen - or equipment - consumables reps.
In the last three decades, with the majority of conventional MIG weld equipment advances, there has been more electronic bells and whistles introduced than real world weld quality - productivity benefits, (see pulsed MIG equipment issues in the programs at this site). With this scenario, it should be a surprise to find in most medium to large size weld shops that can afford to pay for qualified personnel, that when purchasing new MIG equipment, the selection of the poor duability, costly pulsed MIG electronic weld equipment is the norm.
When weld equipment is critical to a companies quality - productivity and profits, it's up to all the responsible managers, engineers and supervisors to figure out the requirements that will allow them to take full ownership.
Of course I recognize that there are many global weld manufacturing facilities that have got it right, however I can simply let you know what my experiences were. And over the last five decades, I found that in the 1000 plus companies that I visited, that the companies that were in complete control of the MIG and FCA process were less than 5 percent.
You may not want to ask MIG -FCA weld
process questions at these applications.
Weld Responsibility -
Accountability - Ownership!
The following will tell you something about the common management -
engineering weld process control apathy and lack of process ownership that is too often found throughout the global heavy fabrication industry.
It's a sad fact that with the majority of large scale weld projects, you will find that many of the managers and engineers responsible for the welds are working behind a glass wall that allows them to be visable but at the same times isolate them to whats happening on the weld shop floor.
Is a sad fact that
in too many weld shops, the persons responsible for the weld inspection personnel that spend their days "revealing and documenting the weld defects, will rarely have the process control expertise that would enable them to hepl the welders reduce those weld defects.
WELD QUALITY AND PRODUCTIVITY
It's a sad fact that in many global ship yards, its hard to find out who is responsible for the welds being made, and when qualified weld engineers have been hired you will find that there hands are often tied as the senior poor ship yard management will have enabled the less qualified weld supervisors to have more weld responsibility - ownership for the weld processes used.
WHAT ARE IMPORTANT QUALIFICATIONS FOR WELD MANAGEMENT & SUPERVISION?
A qualified weld manager is aware of the weld fumes and weld dust hazards, and the weld - cutting - grinding - electrical safety requirements necessary for the protection of the weld department personnel..
A qualified weld manager would be an individual that fully understands the equipment, the processes and the Process Controls - weld Best Practices that are necessary for all the weld personnel to consistently attain the highest weld quality and productivity.
A qualified weld manager will teach their employees on the methods that will reduce the formation of weld defects.
The weld manager should be aware how to always attain he highest weld productivity at the lowest possible weld costs.
A qualified weld manager will ensure the equipment in the shop is both uniform and the most durable available, and that the equipment is well maintained and calibrated each year.
The weld manager would ensure that no one on the weld shop floor will be playing around with their weld controls.
The weld manger would not require weld advice from any salesman.
The weld manager would be aware of the process control education, the weld skills and the best weld practice training that is necessary for the employees to optimize the equipment and consumables utilized.
WHY DOES THIS GLOBAL WELD INDUSTRY TYPICALLY TAKE THE "COSTLY ROUTE" OF EMPLOYING INSPECTION PERSONNEL THAT SPEND THEIR DAYS FINDING AND REPORTING WELD DEFECTS AFTER THE WELDS ARE COMPLETE? SURELY IT WOULD BE MORE LOGICAL TO TRAIN THESE PERSONNEL WITH THE WELD PROCESS CONTROL - BEST PRACTICE KNOWLEDGE THAT WILL HELP THEM ADVISE THE WELD PERSONNEL HOW TO MINIMIZE THE FORMATION OF THOSE WELD DEFECTS.
Every weld mfg. facility should examine the resources and budgets of their QA - Inspection Departments, and then in contrast examine the resources and budgets and training time and dollars spent on placing personnel on the shop that could actually assist in the prevention of the weld defects.
THERE ARE FEW DEMANDS FOR WELD MANAGERS BUT ALWAYS HIGH DEMAND FOR WELD QA MANAGERS:
LEADERS EMPLOYED IN A TECHNICAL INDUSTRY SHOULD NEVER HAVE TO ASK A SALESMAN OR A BIASED REP.
FOR GODS SAKE, CUT THAT UMBILICAL CORD:
industries and companies which daily reveal common costly weld issues, a frequent management
crutch approach to solving the weld problems, is to turn to a salesman or product rep for advice. Of course that biased advice often will lead to the purchase of so called
sophisticated, costly MIG pulsed MIG power sources. And lets face it, what's the use of sophisticated weld equipment without costly useless thee part gas mixes and the latest over priced and often unnecessary Metal Cored or Flux Cored weld wires.
THOSE WELD DECISION MAKERS THAT HAVE NOT LEARNT FROM THE WELDING PAST, WILL OFTEN WASTE TIME ENERGY AND MONEY IN THE THEIR FUTURE WELD ENDEAVOURS.
I have made optimum MIG and flux cored weld quality - productivity for decades, and my welds were typically produced on low cost, durable CV MIG equipment with
simple two component argon - CO2 gas mixes and E70S-3 MIG wires that have not changed since the nineteen sixties. With this in mind
surely management that looks to its bottom line, has a responsibility to recognize that too frequently their
weld issues are simply not an equipment or consumable issue that requires sales advice, but simply a result of the general lack of their own and their weld departments weld best practices - process control expertise.
A Generalization on the MIG - Flux
Cored Weld Industry.
"MOST OF THOSE EMPLOYED IN THE WELD INDUSTRY ARE
SELF TAUGHT, UNFORTUNATELY WITH THE MIG AND FLUX CORED PROCESS, THE SAD REALITY IS MOST ARE TAUGHT WRONG":
2001: The global
MIG and flux cored weld industry has for decades been in general a "Self Taught" industry. This industry
evolved from using mostly two simple manual weld processes, SMAW (Stick) and GTAW (TIG). When community colleges and the weld schools such as those typically found in ship yards teach MIG and flux cored, their education focus is frequently the same as what it was in the nineteen sixties with the focus on teaching SMAW or Oxy Fuel weld skills. The sad reality is most weld training facilities do not teach the best weld practice - process controls necessary for process optimization with the NIG and Flux Cored weld processes.
When many of today's welders, technicians and engineering students graduate from their weld courses and go for a job, they will be employed to work along side more experienced weld personnel in the plants, and they can join them as they all "play around with their weld controls"
In contrast to the SMAW and TIG process, MIG equipment offers all
types of weld transfer modes such as short circuit, globular, spray, pulsed, STT,
RMD and CMT. Each MIG transfer mode will have an optimum weld parameter range suited to the wire diameter and weld gas mix selected. Also the MIG equipment may also be utilized for the flux cored process which has different rules for weld diameters and weld positions.
To control MIG and flux cored weld quality - productivity requires;
[a] focus on the denominators that can simplify the teaching of weld process controls,
(my clock method),
[b] focus on the optimum best weld practices for the intended process - consumables and application,
[c] provide employess with the ability to separate sales BS from what's real.
(these are things my training programs provide).
My question is a simple one. Why would any company complain about the welders impact on the weld quality - productivity with the MIG and flux cored weld processes, when that same
company employs engineers, technicians and supervisors who if they were required to weld, would also have to "play around" with the weld controls.
Surely an experienced management would make sure it provides all it's weld decision makers with the best practices and and process
control expertise necessary to attain consistent, optimum weld quality and productivity from the processes they utilize?
you believe you and your key weld personnel have MIG and flux cored weld process control expertise, take a look
at the following fundamental weld tests, and then ask your self, how well would my weld personnel
do with this test, and would this type of type weld process expertise benefit our organization?
 Fundamental MIG Process Control Weld
 Fundamental Flux Cored Process Control Weld Test
 Solutions to all your MIG and flux cored process
control issues are here.
is the only web site in North America that promotes the management and engineering
process ownership message. I encourage managers and engineers to use the resources available
at this site
to implement MIG and flux cored, best weld practices and process controls.
Weld Management - Expertise - Responsibility - Accountability - Ownership.
do many large scale weld projects like ship yards have in
the auto - truck industry plants and robots?
do the large scale weld projects as found in ship yards, have in
the auto - truck industry plants and their robots?
 Lack of general weld best practices and weld process control expertise:
It's not difficult to find both managers and engineers who will daily struggle with the world's two most widely used weld processes used in their weld shops.
 Lack of manufacturing controls for the parts welded:
In these two industries you will
find too many parts that have excess weld gaps or part dimensional tolerances
which are not within the weld design tolerance requirements. Also you will find that most weld shops are weak in providing appropriate manufacturing instructions.
Inadequate weld process control - best practice training:
Like many ship yards and other large scale weld projects, as it is in the auto - truck plants, you will find the majority of weld personnel have to "play around" with their weld controls.
Minimal management weld cost expertise:
In most weld facilities, you don't want
to ask anyone in management or supervision the real cost of the world's most common 1/4 (6 mm) MIG or flux cored fillet weld.
 Weld quality - inspection practices that are backwards:
Most weld quality programs are developed to find
weld defects after the welds are complete:
In most weld facilities, you
will find extensive QA resources directed to find welding defects and limited
manpower and human resources directed at preventing weld defects.
 Weld equipment and consumable selection nonsense:
From the ship yard to the car plant, you will see either the wrong weld equipment or a mindless array of unnecessary, over priced weld equipment and consumables. The reason for the lack of uniform and unnecessary high priced weld equipment and lconsumables is a simple one. When weld management and supervision do not understand what it takes to make optimum weld quality and productivity, they turn to their crutch, his name is "weld sales rep". This is the sales person who typically has never run a weld shop. The rep will too often provide biased advise to justify his companies overpriced MIG equipment which is loaded with useless electronic bells and whistles. Hey if your organization can be sold useless MIG equipment then your company is a sales man dream account and the next product will be a special MIG gas mix. This BS has been going on for decades, and the results can be viewed in most global weld weld shops.
WHEN A TECHNICAL INDUSTRY SUCH AS THE WELD INDUSTRY HAS TO RELY ON INEXPERIENCED WELD SALES ADVICE, THE EXECUTIVES IN THAT INDUSTRY ESPECIALLY IN SHIP YARDS AND OTHER LARGE SCALE WELD PROJECTS NEEDS TO FOCUS ON THE PROCESS CONTROL EDUCATION THEY WILL ENABLE THEM TO CUT THE SALES UMBILICAL CORD AND GET CONTROL OF THE PROCESSES AND EQUIPMENT THAT ARE IMPORTANT TO THEIR ORGANIZATION.
WHEN AN INDUSTRY UTILIZES WELD PROCESSES THAT WERE DEVELOPED BEFORE MOST OF THE PEOPLE USING THEM WERE BORN, AND IN GENERAL THIS INDUSTRY CANNOT FULLY CONTROL THOSE WELD PROCESESS, SOMETHING NEEDS TO CHANGE, AND THAT CHANGE HAS TO BE DRIVEN BY MANAGEMENT:
PIPES AND A MULTI- MILLION DOLLAR WELD COST REDUCTION:
Ed created an annual, one
million dollar weld cost reduction
for the Imperial Oil, (Aberta CN).pipe shop - pipe line weld contractors.
2015: HOW IMPERIAL OIL HAS SAVED AT LEAST TEN MILLION DOLLARS
In 1998, Imperial Oil management in Alberta Canada asked if I would:
A. Evaluate the oil and
natural gas field and shop pipeline welding practices
used by their prime contractors in Alberta, Canada.
B. Evaluate the weld methods that would reduce
field pipeline construction welding costs on a steam pipe project.
C. Promote the use of the
manual flux-cored-arc welding process so that reluctant stick welders and weld supervision
fully inderstood and accepted this process in the field and fabrication shops.
D. Train the senior stick
pipeline welders, supervisors and engineers with flux cored process controls - best practices.
To attain across the board acceptance
of the flux cored process, I decided that the
best strategy would be to gather all the key weld personnel at a location
in which both classroom and hands on weld training could be provided. The
Southern Alberta Institute of Technology (SAIT) located in Calgary, Canada,
kindly provided us with one of the best equipped weld training facilities
in North American.
For the flux cored introduction
and weld process training, I developed an intensive three-day training session.
The weld best practice - process control training required both classroom and hands-on pipe welding
for the pipe line contractor's key welding personnel.
The flux cored weld
training covered the requirements to weld carbon steel pipe diameters that
varied from 100 to 600 mm (4 to 24 in.) diameter. The training provided the
welders with the required flux cored practices - technique and skills . The training also placed great emphasis on ensuring the participants had the
flux cored weld process control knowledge necessary to "set optimum weld parameters"
for any manual or automated, E71T-1 consumable and pipe application, Ed use his weld clock method to teach the parameters and the weld personnel did not have to take notes.
The flux cored training program was well received by all,
and in less than 16 hours of welding pipes and discussing the necessary weld
process controls - best weld practices, we had one hundred percent acceptance from the participants who
before were concerned with the major change from the pipe SMAW process. After completing the training,
I then followed up with visits to the companies pipe shop to provide weld
process support during the SMAW to flux cored transition.
The Primary Pipe
for Imperial Oil:
The goal of the SMAW to flux cored conversion
was to improve weld quality and generate cost savings when welding low alloy
steam pipes. A common pipe application was a sixteen-inch (40-cm) diameter pipe, with a 1 inch. (25-mm) thick
wall, and a 60-degree bevel for the weld. The steam pipe, CSA Grade 448 (X65),
2,500 psi, at 650 F. The pipe has a specified minimum yield strength of 65,000 psi, with
UTS at 80,000 psi.
The pipe weld qualification was to ASME B31.3, with required weld tests performed
to ASME Section IX.
One of the main differences from a traditional pipeline
code is that the bend test subjects the weld to a 20 percent strain, compared
to 12.5 percent strain for many pipeline qualification tests.
The steam pipe used to be welded with E8010G electrodes. The SMAW process required
the use of 350 F preheat to prevent hydrogen cracking. In selecting a suitable
flux cored consumable I tested many of the available all position E71T-1 /
E81T-1 flux cored wires. The flux cored wire I found most suitable was an
Alloy Rod product.
The E71T-1, Alloy Rod flux-cored
electrode selected had the best weld puddle control especially in the critical
and difficult overhead pipe welding position. The E71T-1 wire was developed for
use with straight CO2. However when I tried this wire with an argon CO2 mix
the weld transfer was optimum and the weld provided a minimum of 90,000 psi
The success of the flux-cored wires
on this project eventually prompted a change from the traditional 60 degree
bevel to a compound bevel that dramatically reduced the required amount of
filler weld metal. The controlled low hydrogen content of the flux-cored wires
also allowed reduction of the 350 F preheat to 200 F. These two changes provided
dramatic cost reductions that are not included in this report.
Management, Process, and Pipe Welding Considerations
For many decades, pipe spool shops
and pipelines have made the majority of their welds with SMAW electrodes or
with the gas tungsten arc process. Although the SMAW electrodes, arc characteristics
and properties have improved in the last three decades, these electrode in
contrast to gas shielded flux cored electrodes provide lower weld fusion potential,
lower weld deposition rates and lower weld deposition efficiency.
2007: Pipe Welding and Process Choices.
When used in most pipe shops, the MIG equipment with it's MIG and flux cored weld transfer modes are rarely optimized.
Flux cored wire manufacturers have been frustrated for decades with the slow pace that their products evolved throughout the code pipe and pressure vessel industry. Their frustration was further increased when they saw the same industry get caught up with the electronic modified MIG transfer modes such as pulsed MIG and STT and RMD, these two weld process were only suited to specific open root welds.
PIPE FILL PASS AND WELD PROCESSES AND EQUIPMENT LOGIC:
I believe while the traditional pulsed MIG process is an acceptable process for "mechanized fill pass welds", however on the MANUAL welds, pulsed MIG cannot out perform all position
flux cored wires used with low cost MIG equipment or CV generators especially when welding with 5G with wall thickness > 7 mm. Also and I hope this shocks many weld shops that paid for that high priced pulsed MIG equipment, the pulsed MIG process cannot outperform regular low cost MIG equipment when its set at the low end of MIG spray transfer settings on " rotated steel and alloy steel pipe fill joints" .
the pulsed MIG process infatuation has more to do with weld process ignorance and weld equipment marketing
and salesmanship than it has to do with manual weld performance. I have evaluated pulsed MIG equipment for approx. 30 years. I believe that the common lack of weld fusion from the pulsed process are derived from the high deposition / moderate weld energy thats derived from a process that spends 50% of it's time at a low back ground current of typically less than 100 amps. You won't read this anywhere else but for 30 plus years, if you have used pulsed MIG on steel parts over 5 mm, this process has always provided a poor ratio of weld energy to the weld mass produced and the weld speeds required.
THE PIPE ROOT PASS AND WELD PROCESS - EQUIPMENT LOGIC:
The picture on the right is me testing the MIG STT - RMD in contrast to the d regular Short Circuit modes on the Imperial Oil. natural gas, 5G pipe root welds.
The MIG traditional short circuit
mode is a practical weld choice for welding a pipe root pass with any "rotating"
pipe welds that have controlled open root dimensions. On these pipe root applications, the traditional MIG short
circuit, and globular modes are just as effective as the highly touted and oversold Lincoln STT and Miller RMD equipment for the rotated pipe roots.
The STT - RMD modes are superior to SC when welding 5G especially in the 5 to 7 o'clock over head root positions. Please note pulsed MIG - MIG STT - MIG RMD and the Flux Cored process cannot provide the pipe weld quality that's attained with the TiP TiG process (www.tiptigusa.com). TiP TiG can be used for all position pipe open (or closed) root welds and for all alloy steels fill passes.
CONCERNS WITH MIG and FLUX CORED AND THOSE "NARROW GROOVE" PIPE WELDS:
When using narrow bevel pipe weld
joints, and the pulsed MIG "manual" process, the wise weld
decision maker will remember that this process typically provides only marginal
side wall weld fusion on wide 60 - 80 degree included angle vee groove welds.
Note: The pulsed MIG rules change when pipe automation is utilized and the controls can be applied to the pipe fill pass welds.
For pipe companies using pulsed MIG, the
narrow groove weld results may require extraordinary, costly weld inspection methods. In order to use a narrow bevel and the automatic MIG modes, the weld
inspection from companies aware of the pulsed MIG issues, may require shear wave ultrasonic examination. This mode of inspection
is necessary so the NDT equipment can size the flaw, and determine if it is
acceptable, based on crack, tip opening displacement, (CTOD) and fracture
mechanic equations. This will also require the regulator to accept alternate
Pipeline companies are becoming aware of costs incurred
in this complex inspection criteria and also with the cost of the weld repair
issues that can result. When using weld processes that provide minimum side
wall fusion the necessary field machining of the pipe ends can also obviously
cause issues from the pipe roundness deviations.
Note: TiP TiG is highy sucessful on narrow VEE and J groove welds and lack of weld fusion should not be a concern.
For the following reason the majority of global manufacturing
facilities that use MIG or
would benefit from my MIG and Flux Cored weld best practices - process control training programs:
A. When setting the two
MIG or flux parameter controls on traditional MIG equipment the welders typically will
end up "playing around with the controls."
B. Using gas shielded flux cored? Ask the engineer managing
the process or the welder using the gas-shielded flux-cored wire what the
"optimum, vertical up" wire feed and voltage range are for that wire. Then see the blank
gaze that will often follow.
C. Using spray for 1G pipe fill passes? Ask the welder or the
engineer what the MIG, 0.035 in.
(1 mm) diameter wire feed rate is for the
start point of spray transfer and which is the best gas mix to utilize. and the blank gaze will return.
D. Using short circuit for that 1G root, ask the welder what the optimum wire feed, amps and voltage range is, or whats the best gas mix and torch position and the answers will be interesting.
With the appropriate weld process
expertise, and a short training period, the above manual weld processes and consumables
can be relatively simple to set and operate, however no matter how good the welders are, both MIG and flux cored processes will cause weld defects .
If you weld pipe in shops consider TiP TiG, this is a weld process that can eliminate pipe weld rework and provide the highest possible metallurgical results.,
The progressive and rare Imperial Oil company engineer, wanted his companies's pipe contractors to
more automation on the Cold Lake pipe welds.
The majority of pipe welds by Imperial Oil pipe weld contractors were as mentioned made by the SMAW process. After I had finished training these guys with the semi-automatic flux cored process, Imperial wanted their contractors to consider the utilization of more weld automation.
From welding pipes to welding automobiles, there is no machine that can offer the weld automation benefits that are derived from a robot. However any weld automation requires weld process control knowledge, so it should not be a surprise that in the North America
the robot weld production efficiency rarely exceeds
sixty percent, and on many simple weld robot applications as found in highly engineered automotive plants, the robot weld rework generated is typically 10 to 40 %. The purpose of weld automation is lost when manual welders are required to repair the automated welds.
With robots or pipe weld automation,
we often find the same welding MIG and flux cored weld process issues that are found in the manual
welding shops. One of the biggest challenges any weld decision maker has with automated welds
is to ensure that the automated weld equipment does not inherent
the bad weld practices found in the manual weld shops.
|The prime factor for poor automated weld quality or productivity
is as usual a "lack of weld process control expertise".
To fully optimize the mechanized flux cored or MIG pipe applications, the
A. Be aware of the weld
process controls and best practices fundamentals.
B. With the common wire diameters utolized, be knowledgeable of the
weld parameter ranges for the wires utilized.
C. For the application, be aware of the primary
feature benefits and the disadvantages and defect potential of the different MIG weld transfer modes or the flux cored process.
D. Understand that the primary
method for weld cost control comes from understanding the wire feed and weld
Management can see dramatic weld rework cost reduction through the process control training that they provide their employees. Non-destructive technicians know that the majority of pipe weld defects that
require weld rework and additional costly weld radiographs will occur typically
in the root, and in the first or second fill pass. Defects are also common in the rapid freeze weld Starts and Stops. Most
of the manual weld defects are greatly influenced by the welders using inappropriate
weld settings and poor weld techniques and practices.
It's important for weld decision makers to remember that even when the MIG and flux cored process data and paractices are optimized, that these processes will still produce unacceptable weld defects. For example with pulsed MIG process expect lack of fusion and small porosity especially on wall thiclness > 8 mm. For the flux cored process you should anticipate trapped weld slag, large porosity content, worm tracks and lack of fusion, (see the pulsed MIG and flux cored sections).
Note: There is only one weld process today that is capable of providing manual - automated welds without weld defects. and that process is at www.tiptigusa.com.
In contrast to manual welding, an automated weld process
will change both the weld
process quality & productivity potential,
IN CONTRAST TO MANUAL MIG and FLUX CORED, MIG and flux cored weld "automation" allows control
of the wire stick out, the weld speeds and the weld weaves. These are key elements to improving the pipe weld or clad quality. Of course automation can also dramatically increase
the potential weld productivity attained, and sometimes this is a good thing, however remember that increased productivity leads to faster weld speeds which can reduce the weld fusion attained.
There are almost as many options
to mechanize field pipe welds as there are welding processes. We could weld
the field pipe line with one or two robots mounted on a truck that straddles
the pipe. We could use simple track and carriage equipment or purchase the
more durable and sophisticated automated pipe line welding systems. We can use pulsed MIG, flux cored and process like TiP TiG (www.tiptigusa.com) which provides extra ordinary pipe weld and metallurgical benefits.
With the Imperial Oil, steam pipe
line weld projects, in contrast to the manual stick welders, the mechanized weld
carriage using flux-cored wires enabled the following weld benefits:
1. Provide a reduction in weld start
and stops per pipe joint from more than
100 with the manual SMAW process, to 12 with flux cored.
2. Consistent travel speeds and consistent mechanized
weave control that optimizes weld placement, improving weld fusion with any bevel welds.
3. Consistent weld wire stick out which maintains constant weld energy.
4. With the
mechanized units and a portable weld parameter control, the operator
has the ability to change the weld parameters on the fly if necessary
5. The mechanized unit allows
higher wire feed rates which will increase the weld travel rates.
6. No matter what the weld process utilized, in contrast to inconsistent
manual welders, a mechanized unit will have far superior control of the weld pool and the weld weave
configurations. This is an important consideration with flux cored and its one of the reasons that Pulsed MIG can be sucessful but manual Pulsed MIG will have lack of weld fusion concerns. With the automated flux cored process, the increased weld deposition and ability to do larger
weld weaves should reduce the number of weld passes. For example, the manual
welders do three - four passes for the SMAW pipe cap pass. A mechanized unit with
flux cored will do the cap in one - two passes with a much shorter weld time.
KIS - KIS - KIS. All weld managers should be aware
of the benefits derived by keeping their welding operations simple, and when possible keeping
unnecessary bells and whistles off the mechanized weld equipment and use
a common sense approach to the pipe weld process, consumables and procedures and pipe edge prep equipment selected.
There are too many managers in the pipe industry that will spend hundreds of thousands of dollars on automated pipe weld equipment, and spend nothing on the best practices and process control training, that could optimize the welds.
Weld best practices - process controls (BP - PC) will rarely be instigated on the weld shop floor
or from welders working on a pipe line. The BP - PC should be established by the engineers responsible.
It's unfortunate that most universities
and colleges in North America have failed in providing their mechanical or weld
engineering graduates with BP - PC training. Also
it's unfortunate that at most trade schools, weld educators, who typically have a strong SMA (stick) welding
background, frequently place their MIG and flux cored
training with emphasis on incorrect welder skills, rather and very little focus on BP - PC.
The Imperial Oil Pipe Line Welds
and Gas Shielded Flux Cored Wires:
The common E71T-1 and higher alloy E8T-1 small diameter, gas shielded,
all position, flux-cored wires can provide many unique weld benefits
when used with the traditional Constant Voltage MIG equipment, or with Constant Current Generators
that usually have a CV adapter. Similar to the traditional MIG process, the flux-cored
process requires only two simple weld parameter settings, a volt setting and a variable
wire feed control that regulates the welding current.
Thanks to general lack of focus on the required optimum weld practices and weld process controls, after two decades of use, the flux-cored weld process,
while easy to operate, has inherited "people process issues" that
are international in scope.
In the more than 1,000 manufacturing facilities
I assisted in thirteen countries, more than 80
percent of the weld shops were using:
A. The wrong flux cored wire
diameter. Many weld decision makers will purchase the >1/16 wires for those vertical up welds, while the 0.045 wires in most instances will allow greater weld control with greater current density for improved weld fusion.
Note for weld managers and supervisors. When it comes to optimum weld quality, with weld wires,
bigger is rarely better.
B. The wrong flux cored type. Many of the gas shielded flux cored welds that are made on thick metal applications will be made in the flat and horizontal weld positions. In these weld circumstances, the so called "all position" welds wires such as EX1T-1 are frequently utilized, and the weld reality is they are a poor choice. The all position wire don't have the deoxidizers or the slag that allows the current that should be used on most weldments that are > 7 mm thick, in contrast, the EX0-T1 wires would be better suited.
C. The wrong flux cored shielding gas mix With the gas shielded flux cored wires, you often have a choice of using argon C02 mixes or straight CO2. For large scale applications such as In a ship yard or similar, I would recommend the the E71T-1 Kobelco wires with straight CO2. These weld wires have excellant weld transfer characteristics and enable good weld control with straight CO2. The important attribute of straight CO2 is that it can in contrast to argon - CO2 mixes, provides superior weld fusion which can shut down on the required weld reqork. For welding in buildings where fume issues are a concern, with the E71T-1 wires I would be using using argon with 20% CO2?
Note: The reason I do not recommend the widely used argon - 25% CO2 mix is this mix is poorly suited for the attainment of optimum MIG spray welds, see gas section.
D. The wrong flux cored weld parameters. With too many large projects I would find that the welders were using Inappropriate welding
parameters, or they were using on wire feed and volt weld setting for all the very different welds that they did..
E. The wrong flux cored weld practices. If you asked, few welders could tell you whats going on with the weld every time they change the wire stick outs or why they should not use flux cored for an open root. Even fewer will be aware of the influence of fore hand versus back hand techniques on their welds, or the best weld techniques for welding a root with ceramic backing.
Note the solution to MIG and FCA process optimization is here.
Flux Cored: Pipe Weld
Deposition Rates and Weld Costs.
The gas-shielded flux-cored wires,
specifically those developed in North America by Alloy Rods (ESAB) and later on by Tri
Mark and over seas wire mfgs such as Kobelco, have had the greatest impact on simplifying all position welds on carbon
steels, alloy, and stainless pipe applications. Due to the ease of use and
especially their cost effectiveness, flux-cored wires have painfully wormed their way
into Stick weld entrenched industries such as the ship yards, pipe shops and heavy plate shops.
Weld shops that have poor weld management
will rarely like weld process change.
An average SMAW weld deposition rate
for a vertical up, pipe fill pass welds
would be 2 to 3 lb./hr, (0.9 to 1.3 kg/hr). With the poor SMAW arc on times the hourly SMAW weld deposition may be around 1 pound per- hr. In contrast for the same weld application,
a conservative and "average" manual weld deposition rate of 6 to 9 lb./hr,
is attainable with either the 0.045 and 0.052 in. (1.2
to 1.4 mm) diameter flux-cored wires. With flux cored, the arc on time is also greater than SMAW, and the average hourly FCA weld deposited is typically 2 - 3 lb/hr
There are specific all position flux-cored consumables
from companies like Alloy Rods, Tri Mark and Kobelco that can produce 9 to 10 lb./hr (4.5 kg/hr) for vertical up welds on components
thicker than 8 mm. Remember weld costs are also influenced by weld duty cycle (arc on time) and it's obvious that in contrast to SMAW, the increased arc on times with flux cored should add another 10 - 20% more weld deposition each hour.
For this pipe project I selected
an Alloy Rod E71T-1 0.052 in. (1.4 mm) diameter flux-core wire for all the
5G pipe fill passes and the cap pass. I selected this wire based on its low weld current
requirements and on its welding capability especially in the overhead positions. As the
Alberta stick welders had minimal flux cored experience the initial flux-cored wire feed selected
(current) was conservative and provided a weld deposition rate 6 - 7 lb./hr (> 2.7 kg/hr). The weld parameters I selected enabled the
welders to weld the multi-weld pass 5G pipe fill pass welds with only one wire feed - volt setting and one a slight adjustment of the weld voltage was required for the pipe cap pass.
Flux Cored Weld Process Influence
Weld Layers and
The two manual pipe welders using
the E8010 SMAW electrodes, welded 110 arc starts in 13 fill passes. The low
weld deposition rate produced short weld lengths and layers of welds with
little depth. In contrast the higher weld deposition flux-cored wires reduced
the number of weld layers by 50 percent.
When welding the fill passes using
a mechanized pipe welding system or a simple carriage and track system that
provides two carriages and torches. The 0.052 in. diameter flux-cored wires,
could starting at 6 o'clock and travelling to 12 o'clock, complete half the
diameter of a 16 in. pipe in a single weld pass. Each weld gun would weld
a total of 6 flux-cored fill passes . This could result for this pipe project
in a total 12 arc starts (six each side) for the fill passes in contrast to
the 110 arc starts required with the two manual welders and SMAW electrodes.
With utilizing flux-cored wires
instead of SMAW electrodes, the pipe contractor could reduce the arc starts
and lack of weld fusion potential at the arc starts by almost 90 percent.
When using flux cored instead of pulsed MIG on pipe projects,
the time saved from the greater flux deposition can make up for the time used to clean the slag between weld FCA passes.
For a given weld amps, FCA density (weld enegy) will be greater than MIG.
Benefits of the Flux Cored
"Weld Current Density".
The traditional 3.2, 4, and 4.8
mm SMAW electrodes used for pipe welds use a weld current range of 100 to
180 amps. In contrast the all position, flux-cored wires that are optimum
for pipe welds are 0.045 or 0.052 in. (1.2 or 1.4 mm) diameters. The smaller
flux cored wire diameters typically use an "all postion"weld current range of 160 to 220 A. The flux-cored
weld current range with the smaller electrode diameters creates a higher weld
current density that results in greater arc energy in the weld pool than that
produced by SMAW electrodes.
The high weld energy and resulting
higher weld fluidity of the flux cored weld provides flux cored consumables
with their greatest asset for "manual pipe welds", the potential for superior side
The flux-cored wire is unique in
contrast to the MIG wire in that the FCA process enables higher current density with
fluid welds that produce a fast freeze weld slag. As many of you will be aware, the weld slag generated with an E8010G SMAW electrode
often teneacous in the way it clings to a weld. In contrast a well manufactured
flux-cored wire with the same alloy benefits can produce a weld slag that should peel of while welding.
Flux Cored Features and Benefits
Flux-cored-arc welding offers a
number of features and benefits in contrast to the SMAW process.
1. Flux cored provides higher
weld deposition rates. For this pipe project 75 percent less time was required
to complete the 16 in. pipe joint.
2. Flux cored requires less
arc start and stops. On this pipe project, there was a 80-90 percent less
potential for start stop weld defects.
3. Flux cored provides greater
arc energy with improved weld fluidity. This dramatically reduces the potential
for side wall and arc-start weld fusion defects. With flux cored, today the
normal, manual weld reject rate at the field pipe site is 0 to 1 percent.
In contrast with SMAW electrodes the reject rate was 3%.
4. Flux cored produces smooth
weld tie-ins, and reduces weld undercut potential and the need subsequent
5.Flux cored produces thicker
weld layers. Less filler weld passes reduces the weld tie-ins and the potential
for arc-start fusion defects.
6. Flux cored produces longer
weld lengths, reducing weld tie-ins and improving productivity.
7. Flux cored weld slag
is easy to remove reducing the potential for weld slag entrapment
8. Flux cored provides lower
weld hydrogen content and lower potential to absorb hydrogen, this minimizes
potential for hydrogen cracking issues,
9. Flux cored provides faster
weld travel speeds which can result in lower weld heat input. A benefit for
quenched and tempered pipe.
10. Flux cored requires
less welder skill requirements than both the SMAW and MIG processes. With
this process its easier to train welders and you can expect fewer defects
from welders of all skill levels.
11. This pipe project when
using SMAW required preheat of 350 F. In the cold climate of Northern Canada
its difficult and time consuming to attain this preheat temperature on thick
wall pipe. The lower hydrogen potential of the FCAW electrodes reduced the
weld preheat requirement to 200 F.
The FCAW fill pass features and benefits in contrast to the MIG processes.
1. With flux cored we can
use one weld procedure, a narrow wire feed / voltage range, it can be simpler
2. Flux cored provides a
slag that molds the metal requiring fewer welder skills and slowing the cooling
of the weld which reduces weld porosity potential.
3. Flux cored provides higher
weld energy and a more penetrating weld than either pulsed, STT or globular.
4. Flux cored weld equipment costs much less than pulsed or STT equipment.
5. Flux cored equipment is more durable and easier to repair than electronic
6. Flux cored is less sensitive
to contaminates or arc blow.
Imperial Oil Steam Pipe
Line and "Weld Costs":
When welding the electrode costs
are typically only a small portion of the total welding costs,
it is interesting to compare consumable costs of the previously used SMAW process to the costs associated with the flux-cored process.
The pipe line contractor provided
the following SMAW electrode data. The pipe weld crew of 10 welders and 10
helpers welded 16 pipe joints each day on the 16 in. (40 cm) diameter, one inch wall pipe.
The pipe weld crew comprised of a "tack-root crew", two welders and two
helpers, who welded the root, they then welded one or two hot passes. The
pipe fill passes were made with E8010-G electrodes using four weld crews. Each fill pass crew included
two pipe welders, one either side of the pipe plus two helpers. Each fill welder would weld 13 fill passes and a cap pass. Each
four-man crew would weld 4 pipe joints per day.
Each E8018G 3/16 (4.8 mm) SMAW electrode
used on the 16 in. pipe averaged a weld length of 5 to 6 in. (12.5 - 15 cm).
For each of the 13 fill passes, each welder welded approximately 24 in. (60
cm) of the 48 in. (120 cm) pipe circumference. Four electrodes per pass were
required. Each welder used 50 to 55 electrodes to complete the pipe fill passes.
The SMAW fill passes per pipe joint
required a total of 110 SMAW electrodes. One of the most common weld defects
found in the SMAW pipe welds is lack of weld fusion that occurs at the arc
starts. Given the field conditions, the high quality standards and high number
of arc starts, it is an a tribute to the stick welders skills that their weld
repair rate was less than 3 percent.
The Electrode Costs: There are
approximately eight 3/16 x 14 in. (4.8 mm - 350 mm) SMAW electrodes per pound.
The contractor paid $1.64/lb. (Canadian dollar at that time equals 65 cents to the US dollar)
for the 3/16, E8010 electrodes. The 110 electrodes used for the fill passes
required approximately 13-14 lbs of electrodes at $1.64 lb. = $23 for the
filler metal fill passes, which contained approximately 4 lb. of actual weld
SMAW - FLUX CORED Pipe Weld Process Deposition Efficiency:
If you buy a pound of SMAW electrodes, how much electrode ends
up as weld in the pipe joint? The SMAW electrode actual weld efficiency at this pipe project
averaged 35 - 40 percent. In contrast, the flux-cored wires provided a weld
deposition efficiency of 80 to 85 percent.
For the thirteen fill passes on
the 16 in. pipe weld it took 13-14 lb of SMAW electrodes - 14 lb. x $1.64
= $23. Fourteen pounds of fill pass electrodes that costs $23 for a weld joint that required
approximately 4 lb. of actual weld metal.
In contrast to the SMAW, with the flux cored
process, for each pipe joint we had to purchase 5 lb. of flux-cored filler
at $1.70 lb. x 5 = $8.50, versus the $23 required per pipe fill pass costs for the stick electrodes.
To estimate the annual electrode
costs: In a year with 240 working days per year, the total weld joints for
this pipe project which has gone on for many years could be 3,840. The annual
SMAW electrode costs $23 x 3,840 pipe joints = $88,320 for SMAW electrodes.
The annual flux cored electrode cost $8.50 x 3,840 pipe joints = $32,640.
With MIG or flux cored we have
to add in weld gas costs. The all position flux-cored electrode will use an
75 Ar-25 CO2 gas mix. A typical North American gas cylinder costs $40. The
argon mix cylinder will contain approximately 300 cu/ft. (13 cents per cubic
ft.) The pipe welds will use an average flow rate 35 ft cubic feet / hr. The
fill and cap pass require an arc on time of approximately 45 minutes, using
approximately 27 cubic feet of gas, (27 x 0.13 cents = $3.50 gas cost/joint).
Adding the gas cost to the electrode cost of $8.50 per joint = $12 per total
consumable cost per flux cored joint versus $23 for the SMAW electrodes per
A cylinder of gas will last for
11 to 12 pipe joints. For this project of 16 pipe joints per day, 2 x $40
cylinders per day times 240 days = $19,200 per year. Add cylinder rent and
the gas costs should be approximately $22,000. The annual gas cost when added
to the annual flux-cored wire cost of $32,640 would total a weld consumable
cost of $54,640 in contrast to $88,320 for SMAW. This provides a yearly weld
consumable saving of approximately $34,000.
FLUX CORED WIRE - GAS COSTS SHOULD BE 30 - 40% LESS THAN SMAW ELECTRODE COSTS:
Imperial Oil Pipe Weld Labor Costs:
To complete the fill passes in
this pipe joint, with two welders and two carriages with 0.052 in. (1.4 mm)
diameter flux-cored wires, required six flux cored weld passes for each joint side. For
the six weld passes an average continuous and conservative weld travel rate of 8 in/min. (20
cm/min.) would be selected. To weld each of the 6 fill passes (24 in. of the
pipe circumference) would take approximately 3 minutes x 6 passes = 18 minutes
x 2 carriages = 36 minutes of "actual arc-on-time". With a flux cored weld
deposition rate of 6 lb./hr (2.7 kg/hr) (after slag removal), the 36 minutes delivers 3.6 lb./hr
(1.6 kg/hr) of actual weld metal deposited.
At the pipe site, a total crew
of 37 completed sixteen pipe joints each day. This natural gas and oil producing
site has many of miles of pipe that are run each year. The fill and cap crew
used 8 SMAW welders and 8 helpers, 16 workers to complete the SMAW fill passes on the
With flux cored and the reduced preheat requirement, significantly higher weld
deposition rates and a reduction of grinding between passes,
this process only required 3 welder and helpers, or 6 workers. With flux cored six workers now complete the same amount of work that
16 workers using SMAW produced.
The reader can insert all types
of overhead charges for my weld cost saving reductions. However as an example: If we used a an overhead cost per person at the pipe site as $60/hr, then the
savings with the 10 men reduction would equal to $600/hr. Assuming roughly
2,000 hrs./year employment time, and the annual labor savings would be $1.200,000.
In addition to this there are other substantial cost
savings due to "softer" benefits:
1. Lower weld repair costs.
2. Ability to maintain production
schedules if welders are in short supply.
3. Depending on metallurgy
requirements, there is a potential to eliminate or greatly reduce the required
With reduced labor, weld repair
cost reductions and the later cost reductions incurred from the narrow vee-preps which
greatly decreased the amount of weld labor - consumables required, it is not unrealistic to expect that Imperial Oil would attain a weld cost savings that should readily exceed $1,500,000 annualy
for a project that will continue for decades.
Imperial Oil management used my process control expertise and the FCA process as their catalyst to create process change in a weld work force that was embedded with the stick weld culture. This project then required that those that change to the flux cored process do so with the ability to optimize that process from both a manual and from a "weld automation" perspective. I provided that flux cored weld best practices - process control training. Imperial Oil paid me a few thosand dollars to provide a service that I know has now saved them over ten million dollars. Yes Im'n well aware that the working man never gets rich.
Note: You will find my flux cored and MIG, manual and automated weld process control training programs here.
Note: In 2008 if you are using TIG to weld pipe in your pipe shops, and not using TIP
TiG, you are increasing you pipe weld costs by at least 200% and producing inferior weld quality. .
1980s welds made with 1960 MIG equipment
were used in a MIG power source.
Ed and Zuge made these welds in the 1980s. On left a 316 pipe weld, note the weld fluidity with this sluggish alloy, (evident by the freeze lines). On the right, a vessel that was made completely out of weld metal. Half of this vessel was made with Stainless MIG wire and the other half made out of Hasteloy MIG wire. No water cooling and no electronics used to build this vessel which passed X rays and metallurgical tests, and it only took a few hours to make.
WELD SHOPS RARELY REQUIRE BELLS - WHISTLES TO
PRODUCE OPTIMUM PIPE WELDS:
In the believe it or not column. In the early 1960s, an engineer in
CA developed a MIG power source that could out perform some of the pulsed
MIG power source used today in 2015 on pipe lines or for cladding alloy applications.
This power source that I used in the 1980s (above) could weld carbon steels, stainless, or any alloy in all positions, the welds would meet any weld code requirements, and if necessary you can weld
the root, fill and cap passes with one set of welding parameters. This MIG power source that was not produced by Miller - Lincoln - Hobart or ESAB produced the untouched 5G weld below, was never fully accepted by a USA weld industry that did not undestand this equipment and process potential.
Canadian frigates and MIG and flux cored weld Issues:
This ship yard never knew
was in a state of Weld Process Chaos:
the nineteen nineties, I was invited to provide a weld evaluation for a Canadian Ship Yard. The yard was building frigates for the Canadian
Navy. At the ship yard, most of the welding practices could only be defined "as beyond chaos".
The weld engineers
and engineering management at this Canadian ship yard had enabled poor weld practices and did not appear to understand the
fundamental MIG and flux cored weld processes utilized to weld the Navy frigates. It was also interesting
to note, that thanks to the lack of management process ownership, the few weld engineers in the yard were not allowed to tell
the welders what to do.
The bottom line was the ship yard weld quality and productivity was run by the yard welders, and the vast majority of these welders lacked an
understanding of the MIG and flux cored processes utilized.
Incorrect weld process choices and weld settings for the Frigates.
When you weld a 1/4 (6mm) horizontal fillet weld with MIG or flux cored wire you do so
with a single pass weld using either a MIG Spray mode weld, or a flux cored wire. Both process should attain
a typical weld deposition range of > 10 - 12 lb/hr. With a 30% weld duty cyle a welder who is managed, should be averaging 20 to 25 pounds of weld wire per shift.
AN EASY WAY TO SEE THE WELD PRODUCTIVITY
FACTOR IN ANY LARGE WELD SHOP.
To compete in a global weld market in which the Chinease are welding bridges for the state of California, management have to understand weld deposition rate potential per welder. In a large weld shop where welders weld and someone else does the fitting, if you multiply the total welder man hours by 3, you will see how many pounds of MIG or flux cored weld wire should have been deposited. Then call the purchasing manager, ask them to let you know how much wire was purchased and used. and you will get a grasp of where you are reference weld production potential.
HOW GOOD IS THE MIG OR FLUX CORED WELD PRODUCTION
EFFICIENCYAT YOUR PROJECT?
The average MIG and FCA weld wire usage per eight shift day for weld shops welding parts > 4 mm should be 20 pounds. A highly effiicient weld shop would be depositing > 24 pounds per-shift. Those shops that weld gage < 3 mm, parts should be depositing between 8 - 10 pounds per shift.
Most of the large MIG - flux cored weld projects I visited were only achieving 40 - 60% of the welds that should have been daily deposited. To be aware of how to attain the weld production goals and train the weld personnel on how to achieve these weld goals visit my manual MIG - FCA process control programs.
Note: Single pass welds are fine with horizontal fillet welds up to 5/16. When the horizontal fillet weld size required is larger than 5/16, you would have concern for side wall fusion, the solution is to then weld with 1/4 stringers. Do not allow manual weaves to be used for fillet welds above 5/16 as lack of fusion will occur and excess weld heat will be generated.
IN THIS SHIP YARD, TWO WELD PROCESSES WITH INCORRECT PARAMETERS WERE BEING
USED FOR THE COMMON 1/4 (6.4mm) HORIZONTAL FILLET WELDS.
At this ship yard, to
make the common 1/4, carbon steel, horizontal fillet welds on the frigates, the ship yard
welders would use two welds that were carried out with two weld processes, MIG and gas shielded flux cored.
SOMEONE FORGOT TO TELL THE WELDERS,
IF YOU USE COLD WELD PARAMETERS, YOU
END UP WITH SOMETHING CALLED LACK OF WELD FUSION".
The first horizontal fillet weld pass was made on the 6 - 9 mm steels, with MIG short circuit - globular
weld parameters, depositing 5 - 7 lb/hr. The
short circuit parameters utilized were better suited to welding 0.080 gauge sheet metals.
This first short circuit fillet pass had to result in welds with extensive lack of weld fusion.
For the second pass the welders changed their weld process to flux cored. With flux cored they actually made no weld parameter changes. The flux cored settings ensured the welders would put cold flux cored welds over the top of the cold short circuit welds.
The two fillet weld passes were welds that had more lack of fusion than fusion, and the cold flux cored welds had extensive slag entrapment. Each day approx. 200 hundreds would use these poor weld practices
while they put down thousands of feet of fillet welds on each frigate.
may come as no surprise as I walked around the yard to discover that few in the yard knew what MIG short circuit, globular or spray was and even fewer understood the working range of the E71T-1 flux cored wires used
The short circuit
and globular parameters were used with the 0.045 (1.2mm) wire, set at a typical wire feed
rate of 210 to 280 ipm, 5 - 7 lb/hr with 180 to 240 amps - 19 to 22 volts.
Apart from the extensive spatter, without question, the majority of these welds would result in extensive lack of weld fusion, on
any carbon steel
parts > 4 mm.
add to the horizontal
fillet weld problems generated at the yard, the MIG welds were then followed by
a second cold weld pass made with an 0.045 (1.2 mm), gas shielded "all position"
E71T-1 flux cored wire. The flux cored wire used the same voltages and wire feed settings used with the short circuit MIG settings, 210 to 280 inch/min.
(5 - 7 lb/hr). At these wire feed and volts settings, the fast freeze, E71T-1 flux cored wires used at these low settings had to ensure a
massive amount of lack of weld fusion with the horizontal fillet welds.
Note: The flux cored wire feed settings used for the "horizontal" fillet welds, were very low
To make a single pass, horizontal,1/4 fillet with the 0.045 flux cored wires, you would typically use a wire feed rate of approx. 500 inch/min, (11 lb/hr) with 27 - 28 volts.
The frigate fillet welds under discussion only required visual surface examination, however the majority of the welds in this ship yard would in my book never meet the definition of a sound weld.
To put salt in the Canadian Frigates ship yard management wounds, every weld produced with
the low wire feed (low deposition rate) settings, took each of the 300 welders approx. 50% longer than it should have. This
Canadian yard spent over a million dollars annually on welder training which was producing extraordinary poor weld quality and over seven million dollars per year on unnecessary weld labor costs.
I delivered my weld report to the yard management. The report provided the required data and practices for the yard to get it's
welds to the quality and productivity they should have been attaining.
was later informed that my weld report never got as far as the first manager who reviewed
it. The report then disappeared. I was later told by a weld suppler to the yard that the manager was too embarrassed to present the report to his executive
team and also he did not want the Canadian Navy Brass to be aware of the weld quality
produced and the unnecessary yard over costs generated by the welds.
ALL WELD DECISION MAKERS SHOULD FOCUS ON BEST WELD PRACTICES - PROCESS CONROLS.
WITH THESE SELF TEACHING OR TRAINING RESOURCES. WITH PROCESS EXPERTISE, IT'S
EASY TO GENERATE MULTI-MILLION
DOLLAR COST SAVINGS AT ANY LARGE SCALE WELD PROJECTS:
I PROVIDED TRAINING THAT WOULD REDUCE THE OIL TANKER
WELD REPAIR COSTS BY AT LEAST 8 MILLION DOLLARS PER SHIP
In building a fleet of oil tankers in Philadelphia, Aker Kvaerner, a global ship building company had budgeted a few hundred thousand dollars per ship for its projected weld repairs. In 2007, I was called in to help this yard with it's weld quality and productivity problems. At this time the weld repair costs per oil tanker was over approx eight million dollars. .
The prime manual weld process at the yard was the gas shielded flux cored weld process. Most of the 300 welders in the yard used E71T-1 (1.2 mm)
flux cored wires to weld all position, vee groove,
9 to 25mm, steel joints that had
ceramic backing for the open roots.
many ship yards, the Aker management, engineers and QA personnel knew little about the flux cored and MIG processes, their experience was usually with the SMAW (stick) process, a process in which weld skills is the prime requirement and minimal weld process expertise is requied.
In this yard, as it is with too many large scale weld projects, the flux cored welder training focus was on the "welder's skills, and the skills taught were in reality cast offs from the SMAW process and incorrect for flux cored. The ship yard training provided no best weld practices and process controls, both of which are essential to optimize both flux cored and MIG weld quality and productivity.
To work at the yard, welders had to pass an all position, flux cored
weld tests with ceramic backed vee groove welds, (6 mm root gaps) The welds were to be made in accordance with the yards weld procedures.
TOO OFTEN THE WELD QUALIFICATION TESTS ARE IRRELEVANT TO THE WELDS MADE ON THE ACTUAL APPLICATIONS. It's important to emphasize, that like many weld applications, the weld qualification tests and data generated during tests under ideal weld circumstances will have little in common with
the real world weld joints typically found
in the weld shop or yard.
This ship yard was managed by managers - engineers who simply lacked the awareness of the unique requirements necessary to attain consistent
optimum manual or automated flux cored weld quality for vee groove, ceramic backed welds. This lack of process control expertise appears to be common in many
ship yards and large scale weld projects and typically as seen at this site it can have dire weld cost consequences.
THE EXTRAORDINARY OVER BUDGET WELD REWORK COSTS WOULD NOT CHANGE TILL ALL
THOSE INVOLVED, (INCLUDING THE FRONT OFFICE) FULLY UNDERSTOOD THE PROCESSES
I insisted that all the welders, supervisors, engineers, managers and QA personnel in the yard participate in my unique Flux Cored Weld Best Practices - Process
Control Training Program.
Note: This weld process training program requires approx. ten hours, "five hours classroom and five hours hands on".
In a few weeks my
training was complete for the 300 welders and the weld decision makers. The ship yard QA department were given the responsibility to evaluate the weld cost saving results through the weekly reductions with the weld rework.
months after my flux cored weld process control the training, the ship yard
QA department indicated > 50% reduction
in the required weld rework per-ship. The
ship yard management reported that the reduced weld rework, labour and NDT costs,
would result "at that time" in a weld cost savings of approx. 4 million dollars per-ship. As the weld rework was still decreasing further cost reductions were projected.
Ed's MIG and flux cored self teaching or training programs are available at this site
decades as the prime process in ship yards was SMAW, a weld process that requires minimum weld process control expertise, a process in which weld skills are very important.
HOW MANY MORE DECADES WILL WE REQUIRE FOR MANAGERS TO REALIZE THAT SMAW HAS NOTHING IN COMMON WITH MIG OR FLUX CORED?
The reality is the SMAW process
has nothing in common with the flux cored or MIG process. It's not unusual
for weld personnel to have many weeks of flux cored hands on training at the ship yards, and then
at the training completion find that when it comes to MIG and flux cored welds, the ship yard or weld personnel that have under gone weld training will do the following;
PLAY AROUND: Many welders will play around with two simple MIG or flux cored weld controls that have not changed in sixty years, The welders and their supervisors will rarely be able to dial in the optimum flux cored weld settings
Vee groove root, hot pass, fill pass and cap passes. And don't ask that welder to tell you the optimum MIG settings for that common horizontal 1/4 fillet weld.
[b] LIMITED WELD ADJUSTMENTS: Instead of optimizing the welds through the MIG weld equipment controls, many welders will typically find one weld setting and if they cant find one, the welder may copy the settings of another welder although that welder is doing a very different weld. A welder should be ables to make optimum weld parameter changes that suit the conditions they have to deal with. Imagine how annoyed a machine shop supervisor would be, if his lath and milling machine operators used one control setting for every different job they were given.
[c] WHAT BEST MIG - FCA BEST WELD PRACTICES? As they have rarely recieved best practce training, it should be no surprise that most MIG and flux cored welders will not utilize the optimum weld practices - techniques required for either the MIG or flux cored process.
[d] WHOS CONTROLLING THE WELD COSTS? Lack of management, engineer, supervisor and welder awareness of the wire feed to weld
deposition relationship and the weld deposition rate potential for the common flux cored or MIG welds certainly makes it difficult to control weld costs.
A BREAK DOWN OF THE WELD COST SAVINGS GENERATED FOR THIS SHIP YARD:
the following ship yard weld cost reduction and the weld benefits attained from my unique process
control training program. Many mangers may not be keen on training as in the past the weld training did not improve the weld quality or productivity. (Managers, if you dont provide the right training you don't get the results). Training cost money, and the larger the weld shop the greater the training costs. With this in mind it should be no surprise to find some one in management that may be worried about the production man hours lost for training their employees.
Weld Best Practices - Process Control Training Costs:
The Acker training program I produced, required 300 x 8 man/hrs. = 2400
man hours at an approx. weld labor overhead cost of $30/hr. The base labour training cost for the ship yard training was $72,000. To this add the actual training and material costs was approx. $100,000.
Total training costs for the 300 welders was approx. $172,000.
Shipi Yard Weld Rework Cost Reduction Savings Per-Ship:
The initial weld improvement results revealed an instant savings of four million dollars. With management - engineering and supervision focus on maintaining the skills - process control expertise required, the reduction in weld rework costs will continue and could easily reach 7 million dollars on each oil tanker produced.
Ship Yard Weld Cost Reduction from Increased Weld Productivity:
An unreported weld cost fact from the Aker yard was the changes that I created in the
development of the new weld procedures. My weld procedures generated a dramatic increase in the gas shielded flux cored wire feed rates,
(increasing the weld deposition rates). The new weld procedures increased the daily weld productivity
potential per-man in the range from 25 to 35%. If the managers and supervisors kept their focus on weld deposition potential, it would be easy for the yard to attain a weld labor cost reduction per ship of between four and five million dollars.
Ship Yard Weld Cost Reductions from welding the Correct Size Weld Joints:
If this ship yard manufacturing management, engineers, supervisors and fitters, decided to provide the weld joints in accoradance with the design dimensions and tolerances it would be easy to reduce the weld labor and rework by another 1 to 2 million dollars per-ship.
Ship Yard Management - Ownership - Responsibility - Accountability.
The savings for each oil tanker could readily achieve "10 to 14 million dollars". Larger ships built at the yard would provide increased weld cost savings. The welders have the skills which when combined with the best practices and process control training they recieved has given them the resources they require. To sustain the weld cost savings and weld quality, a commitement is required from the yard management to ensure that they and their engineers and supervisors maintain ownership of the weld processes utilized and be responsible and accountable for the weld quality and productivity attained.
Note I took > 2500 hours to develop the Flux Cored training program available at this site. The weld control clock method I used to simplify the training, was a method I have developed over three decades. This program can be used for any gas shielded flux cored alloys or applications. The program is available in CD Power
Point format for $395 plus shipping.
thanks to the Aker Kvaerner management
to be their short term catalyst for welding change.
When will they ever learn?
the good old stick (SMAW) weld days which for some projects is ongoing, some steel ships broke apart at the welds before they left the dry dock.
These and the catastrophic structural failures that occurred at sea, were often a result of
low hydrogen cracking, poor weld practices, steels with poor chemistry (high impurities) and design ignorance of plate - weld mechanical
properties and the influence of cold temperatures.
the 1980's the majority of ships have been built from high quality,low carbon
steels and welded with low hydrogen SMAW - MIG and flux cored consumables. You would
have thought these two important attributes would have resolved the catastrophic
ship failure issues that occur in >2008.
face it, welds on low carbon steels, are typically supposed to surpass the strength
and ductility of the base steels and if the welds are applied correctly,
the welds and surrounding base metals are not supposed to fail.
The reality is however different, while many ships and oil platforms have plate and pipe
that will be affected by rust, during unforeseen circumstances or severe weather
while the steel parts impregnated with rust stay intact, the welds and weld heat affected zones will tear apart like a wet paper
2007: Is it possible that the global ship building flux cored, lack of best weld
practices and lack of weld process controls are partially responsible for many of the catastrophic
failures that sink many ships each year?
a weld reality that the QA departments in many ship yards / oil platform yards,
while looking for weld defects will place minimal focus on the design fit tolerances and quality standards that are supposed to be applied
to the part fit and daily weld edge preparations. Its also a fact that interpass weld temperatures are often not utilized with multi-pass welds or if specified ignored during the welds by both weld and QA personnel.
picture on the left is a flux cored weld edge prep (made in 2007) at a USA ship yard. Yes the gap opening is larger than one inch. Also that is ice and water, and there was no preheat applied and when welding no interpass temperatures applied during the numerous welds. To add to this pathetic weld situation, the cutting oxides on the edge prep surfaces.
It's a weld reality, that many of the vee groove welds made
on global ships and oil platforms and large stuctural applications will be made on questionable weld joints with
"excess root gaps" and
contaminated wet or cold weld surfaces. Weld joints like this would not be
allowed in any other industry.
The increased root openings not only dramatically adds to the weld labor costs and increased potential for weld defects, the weld heat from the additional weld passes has to have a negative influence on the weld's heat affected zones.
2007: DOES A 1/4 (6 mm) OPEN ROOT GAP ON SHIPS PLATE PROVIDE THE SAME HAZ MECHANICAL PROPERTIES AS AN OPEN ROOT OF 1/2 (12 mm)?
WITH THE EXTRA WELD PASSES, INCREASED HEAT AND INCREASED WELD DEFECTS, YOU WOULD EXPECT THE ANSWER TO BE NO.
THE NEXT QUESTION WOULD BE. WHY ARE THE EXCESS ROOT GAP OPENING TOLERANCES ALLOWED IN BUILDING SHIPS?
Weld qualification tests for critcal ship weld plate joints are typically taken from optimum weld joints with the minimum root gap openings. It would be of interest, if the navy and ship building industry, both of which enable weld speciifications that allow extensive, plus, open root tolerances, (sometimes as much as a 100%) would provide the necessay research to find out;
what the negative weld heat influence will be from the numerous extra weld passes.
[b] what the negative consequences will be from the combinations of the extra weld defect buildup and extra weld heat would be on the mechanical properties,
[c] what is the real world maximum root gap cut off point before the mechanical properties will be outside those specified by the ship's designers? After this research, I would anticipate a dramatic reduction in the open root tolerances, more focus on interpass temperature controls and and stricter part fit controls in the fab shops.
The additional HAZ weld heat provides many questions about the mechanical properties being achieved with many weld joints. Every time I see photos of ships that unexpectantly tear apart at sea, and you see that nice clean straight tear where the welds HAZ is located I think about these weld situations.
|Quick, before it sinks, examine how nice and clean the catastrophic
right down the weld seams.
weld failures on this ship occurred in the locations in which
the welds should
have been sound, as they would have be subject to NDT. With ship welds we need more focus on the weld quality that is being accepted and on the mechanical properties being attained in the weld's HAZ.
2007: It's a weld reality in ship yards and other mega oil and natural gas projects, that many unacceptable variables will
happen to the weld joints and welds and those "variables that impact the welds are typically not considered in
the pre-qualification weld procedures generated".
When the weld personnel are not supplied with the
process control training necessary to deal with the weld shop variables, the welders will typically play
with the weld controls and not provide optimum weld settings to deal with the weld situations.
Weld Quality Standards will have a different meaning for each
company that builds ships or oil platforms. One thing most QA departments will have in common, is their weld quality focus will be on "finding rather than preventing weld defects".
Have we learnt anything about welding ships in the last six decades?
29/07 Note from Ed Craig:
and metallurgists will typically look to the ship's design, steel - alloy compositions,
environment, water temp, weather and the formation of rust for the causes of
many catastrophic ship failures. I wonder how many designers will take into account
that on any global built ship the NDT that examines the internal weld quality is only applied to a small percentage of the ships welds.
CODE WELD PRE- QUALIFICATION TESTS SHOULD BE DONE WITH THE
ALLOWABLE CODE SPECIFICATION "WORSE CASE WELD SITUATIONS" AND WELD PROCEDURES SHOULD COVER ALL THE POSSIBLE CIRCUMSTANCES THAT WILL OCCUR WITH THE WELD APPLICATIONS:
weld joints also contain more weld passes producing more internal weld defects. An increase in weld defects with a weaker plate influenced by a larger HAZ is not a combination any organization should accept.
The Navy stipulates a maximum root gap allowance which in many instances is not adhered to. The weld reality is weld and material metallurgical weld qualification tests should always be carried out with the maximum allowable root gaps.
Unfortunately as the photo on the left indicates there is also the real world weld joints that appear in a ship yard.
every merchant and naval vessel, the common poor control of weld joint dimensions will often lead to over size weld joints. The poor edge preps on these joints leave the vee groove edges with irregular oxide surfaces. Cold plate temperatures, lack of interpass controls by the welders, poor weld parameters and poor weld techniques and lack of care of the consumables used will lead to extensive lack of weld fusion, weld slag inclusions
and weld porosity.
As only a small portion of the so called critical ship welds are subject to NDT, both the navy and merchant navy would do well to put a renewed focus on the weld process control training that is focussed on weld defect prevention. All managers need to be aware that it's just as easy to produce optimum quality welds as it is to produce poor welds.
The following are a sample of recent news paper or web reports
typical weld and related issues that have occured in ship yards. It's true that with large scale weld fabrications it should be no surprise that they are extensive weld issues. It just seems strange that few managers today seem to want to take opportunity to take ownership ot their processes and control of the many variables that can provide dramatic weld cost reductions for their organizations.
The USS Nimitz. As reported by the Navy, only
one weld out of
approximately 100 tested passed the NDT.
the ship's demise from a freak
of nature or from poor welds?
DESIGNERS ASSUME THAT THE SHIPS OR OIL PLATFORMS THEY DESIGN,
ARE BUILT TO
THE WELDING SPECIFICATIONS THEY PROVIDE.
THE WELD REALITY IS
FEW ARE, AND IT'S DIFFICULT TO TEST WELDS ONCE THE SHIP IS ON THE OCEAN FLOOR.
In six decades, have we learnt
anything about welding ships?
amount or type of weld defects found in ship construction
in 2012, has hardly changed
in the last six decades.
the 1940's bad SMAW (stick) welds, weld consumable issues, poor steels and poor
weld practices were responsible for numerous Liberty ship catastrophic failures.
Sixty plus years later, we have achieved what? We have a superior flux cored, TIP TIG
and MIG processes and we use superior steels, yet due to good weld practices, ships and oil
platforms are still at risk for catastrophic failures.
those looking for the structural security attained from the double hull construction that
will occur when building large ships in the next decade, keep in mind that unless ship yards change their
approach to weld best practices and process controls, the double hull ships may simply enable double the amount of bad welds.
DESIGN IS IRRELEVANT WITHOUT SOUND WELDS:
Each week one or two global ships sink, many as a result of weakened
structures from corrosion. How many sink as a result
of bad weld practices?
infamous and highly ineffective Six Sigma Crutch is heading to some to ship yards and large weld fab
shops, even after it has failed with the majority of manual and robot MIG and flux
cored weld applications found in the the big three automotive and truck plants. As you will read at this site, these are the plants
in which engineers are also in abundance, and lack of weld best practices and process expertise is rare.
the QA manger focuses on the ISO paper work, and the inspection reports, the lack of
weld best practices and process control
expertise in his ship yard, leaves many
of the ships welds in a
Be a professional with the processes and consumables utilized.
A note from Ed
yard may use half to a million pounds of flux cored weld wire each year,
however it's rare to find a ship yard that has management and engineers who have established Best Weld Practices
and implemented effective Flux Cored Weld Process Control Training for it weld personnel.
How many ship yard managers and supervisors
are aware of
decades the global shipyard focus has been on the welder's "stick welding
skills while the majority of global ship yard welders that weld with the flux
cored - MIG process, lack weld best practices - process control and consumable expertise.
many weld personnel in ship yards will daily use the unsuitable techniques and skills they learnt
with the lower weld energy, lower weld deposition stick welding process.
flux cored process, the variable size root gaps and the placement of weld across none
conductive ceramic backing requires unique weld considerations and specific instructions
for the all position, root, fill and cap weld passes. A visit to any global ship
yard, would reveal that few welders, supervisors or "engineers" are
aware of the flux cored process and ceramic requirements necessary for consistent
It's a sad comment in a time when MIG and flux cored weld defects inundate ships
and oil platform construction, that at many global ship yards, weld apprentices
will spend more time practicing with stick electrodes than they will with MIG
and flux cored consumables. It's also a weld reality that many weld instructors
when providing MIG and flux cored training, will teach the apprentices inappropriate
stick welding practices and techniques. You dont want to ask any weld instructor in a ship yard this fundamental MIG question. " What is the wire feed and current start point of spray transfer with the world's most common 0.045, E70S-6 MIG wire and argon - 20% CO2"..
YOU CANNOT CONTROL THE WELD QUALITY - PRODUCTIVITY
IF YOU CANNOT CONTROL THE PROCESS.
Try the following fundamental weld process questions.
Process Control Weld Test
Fundamental Flux Cored Process Control Weld Test.
Ed's Unique, MIG and Flux Cored Weld
Process Control Training Resources
- The new amphibious ship San Antonio failed to complete a series of sea trials
in late March, and faces $36 million in repairs during the next three months. The
San Antonio has been plagued by mechanical and structural problems since the Navy
took ownership two years late, in July 2005. Northrup Grumman Ship Systems in
Pascagoula, Miss, built the ship at
a cost of $1.2 billion, roughly $400
million over budget.
5000 liberty ships built, 1000 catastrophic failures right down te weld seam.
|> 2000: Forty years later, with superior steels
and superior weld
many ships without explanation, and in calm
get torn apart like
a wet paper bag.
With optimum flux cored weld consumables and extensive use of a grinder, the gas shielded flux cored process
is perfectly able to produce optimum, all position quality welds on any steel
applications as long as those applications have weld joints that meet the design and code criteria.
The bottom line is MIG or flux cored welds on any ship
should be the strongest part of the ship. The reality with too many structures welds are creating the weakest
decades, on many mega
weld projects, the typical
QA / CWI primary function has been to find fault after the weld completion. Possibly managers could encourage and train these guys to learn how to prevent weld defects, it sure would help the bottom line.
If you don't understand weld costs, you will not likely understand the requirements to attain optimum quality welds.
There are ten individuals, managers, engineers and supervisors having a weld meeting in the ship yard managers office. The discussion is on the increasing weld costs associated with the weld rework on fabricated components that require simple 1/4 flux cored fillet welds. You have provide these guys with the consumable information and the wire feed, amps and volts being utilized. The subject is heated and tempers are on the rise. As a pragmatic individual and the subject is "weld costs", you look around the room and say, "gentlemen there appears to be much confusion here, is there one of us in this room that can tell us the real cost of a 1/4
fillet weld one meter in length"?.
You might want to do this early in the day, because
instead of the few minutes, for most it will take many hours and then the answers will be all over the place. Then again, if you like your job you would be better off not asking this question.
from Ed, please don't shoot the messanger.
Sometimes I feel that my comments
on this site may be seen by some as too critical, however there is a reason
this site is called "weld reality" and I don't just criticize, I provide
highly effective practical weld solutions. To those who are interested in weld best practices
and process controls or weld cost simplification, click
In concern of the future weld liability weld consequences from welds that might fail
those weld shop managers and engineers that are rearing up in defensive exasperation
at my hands off manager - engineer comments and the criticism of the lack of global lack of process control expertise,
please remember that too many of you will this year have to deal with excess weld
budget costs, derived from poor weld production efficiency, over budget NDT costs,
and extra weld rework costs.
The typical common weld issues will of course lead to tight
production schedules which make the weld situation worse as the weld shops now have to drive
production before quality. And lets not forget, the lack of process ownership ensures all involved will continue to work
too many hours and loose too much sleep.
WELD LIABILITY CONSEQUENCES ARE MANY..
course human life is always the first concern,
however there are many other consequences
from failed welds.
person who makes a weld decision, should learn weld process
controls and understand the requirements to prevent defective welds
all the money Ed makes from
weld consulting, he has made
the down payment on his dream "house
wonder how many ship yard or oil platform managers, supervisors and engineers would last
in their jobs, if every weld they were responsible for, was given a 100% UT
or radiograph examination?
ship yard welder was welding USA oil tankers for three years,
and this was his best attempt at a welder requalification test.
The weld equipment and consuambles purchased are
always a reflection of the weld managers expertise.
PURCHASE OF RIDICULOUS WELD EQUIPMENT
AND LACK OF FUNDAMENTAL
PRACTICES AND PROCESS EXPERTISE..
Take a moment look around your weld shop. Watch as the weld personnel "play with their MIG and flux cored weld controls". Evaluate
why you are using a wide variety of unnecessary weld consumables and weld equipment.
Go to your gas cylinder rack and ask your self whay there are more than two gas mixes. Chat with the purchasing mgr and find out how much was spent last year on grinding wheels and other equipment used for cleaning welds. And last, find out how much was paid last year for service, repair and maintenance costs" associated with the electronically sensitive
welding equipment and weld guns purchased.
THERE BE DOUBLE STANDARDS APPLIED TO WELDS AND
SO CALLED CRITICAL SHIP WELDS BE MANUAL OR AUTOMATIC?
In my world every weld produced on a ship or used to fabricate a work bench should be considered critical, after all, whats the purpose of a weld? and why would you not ensure every weld produced is optimum. Also why would any manager allow double standards for welds:
In the ship yard, the structural welds in the center area of the ships are considered critical and subject to internal NDT weld evaluation. When NDT finds defects in these welds, then more weld area is subject to the NDT. This has great weld cost repercussions for the ship builder so these welds are given extra consideration and often the best welders are used on these joints. The point is in any facility that welds, if the correct training is provided there should be no best welders. Welding is not rocket science and there is only one standard that can be applied to all welds. If after the proper training is provided, you get rid of the welders who cannot meet that standard.
many of the weld facilities that I visit, I note manual welders typically will make
long fillet or vee groove welds, when low cost, easy to set up, automatic weld carriage equipment is on a shelf gathering dust. Controlling weld speed, weld weaves and wire stickout is essential if you want to attain consistent, optimum, uniform weld quality.
In the encouragement for flux cored or MIG weld automation,
one of the problems ship and oil platform companies have, is that due to lack
of weld process expertise, especially with the supervisors who should be providing the automation weld training, many welders do not know the correct data to
dial in for the common 3/16 - 1/4 - 5/16 fillet welds.
Ask 10 welders in a yard what
is the MIG or flux cored "wire feed and weld travel rate settings" are for a 1/4 (6 mm) fillet weld and I guarantee you will get 10 different answers.
I have assisted ship yards in the USA, and Canada and in Europe. At the yards I worked with Norwegian, Swedish,
Danish, German, Polish Italian. English, Korean, Japanese, Yanks and Canadians
and and don't forget those tenacious thick skinned, highly intelligent, hairy, canny
Scottish weld personnel. My experiences with these hard working, great
characters indicated that the majority played around with their weld controls
and none had ever received MIG or flux cored weld best practice - process control training, or training in dealing with ceramic backed welds.
From my ship yard experiences,
i developed thicker skin, an increased sense of humour and also developed the
following flux cored, CD. Best Practices - Process Control Training Resources. This program is applicable to all position, open root, steel and ceramic backed, pipe and
plate, fillets and vee groove welds.
Ed's "MIG and Flux Cored" Weld Best Practices - Process Control
WELD MANAGEMENT STARTS WITH "PROCESS - EQUIPMENT AWARENESS":
The first step for ship yard management is be aware of the level of weld process control expertise and reponsibility of the key weld decision makers in the yard. Lets face it, If these guys knew what was needed to minimize weld defects and optimize weld productivity, then the weld and rework costs would not be out of control.
Weld quality responsibility should be in the hands of managers, engineers, technicians and supervisors. Typically the weak link in this chain are the weld or fabrication supervisors. The irony is the supervisors are given more responsibilty for the welders than the engineers and technicians get. Notice that QA persons who find weld defects after the welds are complete are not included.
IF AN ENGINEER IN A SHIP YARD THINKS A WELDER IS NOT CAPABLE OF PRODUCING
THE WELD QUALITY DESIRED, HIS OPINION ON THAT WELDER WILL HAVE LESS MEANINING THAN WHAT THE LESS QUALIFIED SUPERVISOR'S OPINION MIGHT BE.
The second step for ship yard management is the managers have to be aware that the weld equipment, process
and consumables used in their yard rarely reach their full weld quality and productivity
potential. The soution to this is in the training programs provided. Yard management have to be aware that the MIG and flux cored welder training programs provided for weld personnel are obviously not effective, therefore training changes are required and training focus is necessary on teaching all weld personnel best weld practices and weld process controls
The ship yard management needs to be aware that the stick
(SMAW) weldesr with 20 years experience typically only brings incorrect techniques and
bad weld practices to the MIG and flux cored process? There is a global shortage of welders. If the weld management was aware that
when new welders walk into their
yard, few will have seen a ceramic backed root gap.
If something like ceramic backing is unique or rarely utilized in other industries, that means welder's need to undersatnd the best practices and process controls necessary for welding on none conductive ceramics.
As its difficult to hire drug free welders, I dont want to waste ship yard money on testing welders to fail. Before testing welders I would give them a one day training on the best practice and process controls necessary for the process and consumable used in the weld test. I would also provide the welders with the optimum weld settings. With this logic ship yards would have less issues hiring welders?
As a matter of interest to the few managers that read this stuff please note. Any "none welding person" with the right attitude and provided with the correct skills, best practices and process control weld training, should with "ten days training" be able to meet the all position code weld quality requirements necessary for the majority of MIG and flux cored welds in any ship yard.
MANAGEMENT ENSURES SHIP YARD WELDER TRAINING DEALS WITH THE YARD WELD VARIABLES:
While the ship yard management
complains that their weld over cost per-ship is one to ten million dollars, they allow the ship yards fitters to produce oversize weld preps that typically add 30 to a 100% more weld.
In ship yards, thanks to lack of management / engineering focus on providing weld joints that are in compliance with the design, its not uncommon to find weld joints outside the code requirements with variable root weld gaps
8 to 25 mm. These welds will be made. How will the welders react to the techniques and parameter changes
required when welding across the extra size ceramic root gap.
 How does
the welder react when the weld procedure does not require
preheat but the steel is either wet or cold.
 How does the welder react when
they have to put in twice as many welds that are specified in the procedure but
there are no interpass temp controls or information about additional weld passes?
ship and oil platform welders are daily offered unique challenges by fabrication supervisors
who frequently know little about the flux cored or MIG process, supervisors who deliver weld joints that are simply not acceptable. To make their job
a little more complex, ship yard welders often have to make the challenging welds
on the poor oversized edge preps in 20 mph winds, 50 feet up on a scaffold, at minus 20
FOLLOWING ARE A FEW WELD VARIABLES FOUND ON SHIPS AND OIL PLATFORM PROJECTS. THESE
VARIABLES ARE THE REASONS WHY WELDERS REQUIRE THE ABILITY TO WALK UP TO THEIR WELD EQUIPMENT AND INSTANTLY SELECT OPTIMUM WELD
PARAMETERS FOR THE THINGS THAT ARE ABOUT TO IMPACT THEIR WELD QUALITY OR PRODUCTIVITY POTENTIAL.
 narrow, inconsistent root gaps,
variable and excess root gaps,
 a lack of understanding of the unique weld requirements
for ceramic backed
roots with variable gaps,
 poor weld edge preparations,
welding on primer, paint, rust and cutting oxides,
 welding in an inconsistent
daily changing environment,
 difficult weld access,
 extensive difficult, vertical and over head welds,
 recieving weld joints from ship yard fitters who have never
been educated on the cost consequences, the quality liability potential or difficulties
of welding poor weld joints,
 supervisors, managers and engineers making
flux cored and MIG process and equipment welding decisions, when the reality is,
weld knowledge never got past a E7018 stick electrode.
about those ships being built with the higher strength and low alloy steels? My
gut instinct tells me that if a ship yard cannot control the weld issues that
occur with the common low carbon steels, that ship yard will not provide any better controls
on the higher strength or low alloy steels.
In the good old days when
welders deposited a leisurely three or four pounds of stick electrode a shift,
they would be concerned about the sponge like flux on the stick electrodes and it's attraction for The stick electrodes would be protected
(sometimes) in a heated storage oven or electric portable heater.
Most welders on large projects typically only produce 50 - 60%
of the weld they should be producing.
MIG and flux cored welders on large projects should be depositing a minimum of 20 - 23
pounds of weld wire a shift, (few do). The reality is during the construction
of many ships and oil platforms, that due to the lack of
supervision - management focus on attaining weld deposition rates, most welders will typically deposit only
10 to 15 pound of flux cored weld per shift.
Due to lack of logical flux cored weld best practices,
few weld facilities ask the welders to date and time tag new wire reels utilized. Whats normal is the flux cored wires are left out in cold, damp or humid conditions for god knows who knows
contrast to stick welding, which has the flux on the surface of the electrode,
a primary benefit of the flux cored wire is the wire's flux is protected by an
outer steel sheath. Some wire sheaths have a straight butt seam and it's easy
for them to allow moisture through the seam, other wires like the one in the picture
have seams that are designed with a little more consideration for keeping moisture
away from the flux.
With flux cored wires you get what you pay for.
shielded flux cored wires are supposed to be low hydrogen products, however that definition only applies as long as the weld wire is sealed in it's container. The flux in these
wires or the wire surface can readily be be contaminated with moisture, and show me a ship yard where moisture is not an issue.
flux cored, process control training program available on a CD also
with the weld practices necessary for all weld
IT TAKES TO GET HYDROGEN CRACKS STARTED:
High strength steels.
 Large root gaps, plate misalignment, anything
that results in excess weld heat and excess stresses.
 Lack of control on the steel
 Lack of control with preheat and interpass temp
 Lack of history and protection for the flux cored weld consumables
 Lack of awareness of the potential for moisture
in the welding gases utilized
 Lack of process and weld technique knowledge
that could help minimize the effects of moisture
 Lack of concern for
the quality of the weld gases used. Many cylinders and pipes supplying MIG and
flux cored weld gas mixes, will contain moisture.
BEST WELD PRACTICES AND PROCESS
THE CRACKS ARE BOUND TO HAPPEN.
It's inevitable that on that on that one billion
dollar naval vessel,containing high strength steels, that when that vessel leaves
the docks, it will leave with hydrogen cracks.
add misery to misery, the cracks will typically be in the weakened weld's heat
affected zones, along side welds that are bound to contain lack of fusion, slag
inclusions and extensive porosity.
|Please remember when building a ship,
or an oil plat form, a failed weld can have the same consequence
as those weapons of mass
OF FRACTURED STEEL PLATES REMOVED
FROM WELDING SHIPS.
Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK
Author(s) : Williams, M. L. ; Meyerson, M. R. ; Kluge, G. L. ; Dale, L. R.
: Samples of fractured plates from 72 ships were examined, and various laboratory
examinations and tests were made on 113 plates selected from these samples. Information
regarding the structural failures involved was obtained from the cooperating agencies,
and the failures were analysed on the basis of this information combined with
the results of the laboratory investigations. The ship
weld failures usually occurred at low temperatures, and the origin of the fractures
could be traced, invariably, to a point of stress concentration at a geometrical
or metallurgical notch resulting from design details or from welding defects.
Note from me: Fifty
six years have passed since the above reports. When will ship yards get
control of the common welding processes they utilize?
SUPERSTRUCTURE ON FFG 7 CLASS SHIPS HAS EXPERIENCED EXTENSIVE CRACKING. THE CAUSE
OF THE CRACKING HAS BEEN DETERMINED TO BE A COMBINATION OF HIGH DESIGN STRESS
COUPLED WITH POOR WELD QUALITY
I had a good laugh in 2005 when I read in the AWS
magazine about some VP in a ship yard looking at purchasing a CO2 laser for ship welding applications.
This was a yard I was familer with. It was a yard in which the management and engineers were unable to get control of the simple to use, two control, MIG - flux cored process.
This was a yard where the managers had a difficult
time getting their weld personnel to feel comfortable with simple Bug-O welds, (mechanized
MIG or flux cored carriage welds). This was a yard in which none of the weld management understood the cost of a weld. This was a yard in which the managers and supervisors lacked the ability to provide
edge preps and weld gaps that meet the design specifications for flux cored weld, and now this is a yard in which the management wants to to bring a laser into their yard.
IN MY WORLD, A SHIP YARD WOULD BE RUN LIKE A NAVY SHIP:
yard management would do well to compare themselves with the way the navy runs a ship
and submarine. A captain or engineer on these vessels typically has the ability to operate or take apart most things on the ship. I
am not suggesting that today that this comprehensive, technical expertise
should be part of this generation's
manufacturing managers job description, (it should however be part of an engineers job description). I am suggesting that in 2012
the global weld industry would benefit from a compromise in which managers and
engineers have less reliance on salesmen or weld equipment rep and show more ownership interest in
the equipment responsible for building their products.
get manufacturing management and engineers back into the weld equipment process control
loop, an important first step would be for these individuals to show the workers
that when they open their mouths on the subject of welding, they can provide welders
on the shop floor something most don't have "weld process control knowledge".
If you are looking
for excellent MIG and flux cored weld process control knowledge resource, it's here.
IF MANAGERS, ENGINEERS AND SUPERVISORS LACK THE ABILITY TO CONTROL
THEIR WELD PROCESSES, THEY WILL TYPICALLY LEAVE IT THE THOSE LOWER PAID
GUYS IN THE WELD
SHOP TO EVALUATE NEW OR DIFFERENT WELD TECHNOLOGY.
evolution from the shielded metal arc welding (stick) process, to the gas shielded
flux cored welding process has for many pressure vessel shops, pipe shops
and pipe line contractors been painful and slow. The flux cored wires that
offered many practical benefits for all position welds were developed > twenty five ago.
The weld reality for those industries that weld pipe lines or and code projects with the SMAW process, is the gas shielded flux cored weld process evolution for most all position code application should have taken a few weeks.
Note: When the management and engineers don't provide weld process ownership, the so called weld decision makers will leave it to their welders to test new weld wires or gas mixes.
Some of the greatest resistance to the uses of flux cored wires came from the global pipe weld shops that supply the oil industry. These weld shops like ship yards were entrenched in SMAW (stick) weld practices, and the unqualified reps who were selling the flux cored wires lacked the process expertise necessary to optimize the flux cored weld performance and therefore could not convince
the stick pipe welders to accept the superior flux
The majority of welders will lack the best practices and process control expertise necessary for weld consumable evaluation, and therefore the new consumable weld test results will often be poor.
Also what motivation will welders have for going outside their comfort zones and recommending something new that would require major learning curve changes for the shop?
HAPPY WITH A PROCESS THAT REQUIRES MINIMAL PROCESS CONTROL EXPERTISE:
As the SMAW equipment provides
a single weld current control, the
STICK welder simply increases or decreases the weld current and therefore needs minimal weld process control expertise. In most instances even the choice
of the electrode is made for the welder. In contrast to the SMAW process,
the MIG equipment that's also used for flux cored welding allows a welder to use
seven distinct modes of weld transfer for MIG - FCA welds..
The reality today in 2012 is that most of the weld shops that use the common MIG and flux cored processes will have focus on the welder's skills rather than on the
welder's weld process control expertise. Every day in these weld shops you will find that the MIG equipment and consumables are rarely used to provide their full weld quality - productivity potential and therefore every day weld costs are more than they need to be. The upside is in most weld shops there is always good potential for dramatic weld cost savings.
WELDERS WILL NOT FEEL COMFORTABLE WITH WIRE FEED PROCESSES UNTIL SOME INDIVIDUAL STEPS UP TO THE PLATE AND TEACHES THEM THE BEST PRACTICES AND PROCESS CONTROLS NECESSARY TO OPTIMIZE THESE TWO PROCESSES. PLEASE NOTE. YOU DO NOT NEED WELD EXPERTISE TO PRESENT MY UNIQUE WELD PROCESS CONTROL TRAINING RESOURCES.
HOW BAD WELDS
of USS Thresher (SSN-593)
company with Skylark (ASR-20), the USS Thresher put to sea on 10 April 1963 for
deep-diving exercises. In addition to her 16 officers and 96 enlisted men, the
submarine carried 17 civilian technicians to observe her performance during the
deep-diving tests. Fifteen minutes after reaching her assigned test depth, the
submarine communicated with Skylark by underwater telephone, appraising the submarine
rescue ship of difficulties. Garbled transmissions indicated that--far below the
surface--things were going wrong. Suddenly, listeners in Skylark heard a noise
"like air rushing into an air tank"--then, silence.
to reestablish contact with Thresher failed, and a search group was formed in
an attempt to locate the submarine. Rescue ship Recovery (ASR-43) subsequently
recovered bits of debris, including gloves and bits of internal insulation. Photographs
taken by bathyscaph Trieste proved that the submarine had broken up, taking all
hands on board to their deaths in 5,500 of water, some 220 miles east of Boston.
Thresher was officially declared lost in April 1963.
a Court of Inquiry was convened and, after studying pictures and other data, they said that the loss of Thresher was in all probability due to
a casting, piping, or weld failures that flooded the engine room with
water. This water probably caused electrical failures that automatically shutdown
the nuclear reactor, causing an initial power loss and the eventual loss of the
How lack of metallurgical expertise
cold water helped destroy the Titanic.
Eight More Ships with Structural - Weld Problems.
Marine Log Home Page:
classification society RINA, Genoa, says its initial findings on the causes of
the sinking of the Maltese-flag tanker Erika during a major storm in December
point to a small structural failure or leak low down in the hull structure. This
was followed by cracking that eventually led to the collapse of the hull.
says its investigations prove that the calculated residual strength of the vessel
at the time of the casualty should have been sufficient
to withstand normal operation of the vessel in the prevailing weather. The residual strength was within IACS limits.
investigations show that the hull structure initially failed at some point low
in the hull, and that complete failure occurred only after cracks had propagated
from that source.
is continue its investigations to determine the cause of that initial failure
and the results of the subsequent actions of the master, owners and other parties
involved. RINA will focus on several potential causes of the initial failure,
possible poor loading or poor ship handling,
 poor workmanship during weld repairs,
 failure of welds due to poor design and poor weld practices during it's construction.
RINA has appointed Three Quays Marine Service and Studio Tecnico Navale Ansaldo
to conduct further independent investigations covering: design and construction
of the Erika and its seven sister ships. "Eight sister ships of the Erika
class were built, under two different class societies, and have been classed by
five different IACS classification societies at some time in their lives. All of these ships had suffered structural problems. Three of them, other
than the Erika, were serious. No information on this history of problems was available
to RINA," he says.
Note: It appears that in the case of the Prestige and the Erika tankers that the
structural failures occurred a few months after welding
repairs were carried out on the hulls. This would suggest that welding
could be a factor in the structural failures.
IF THE BAD WELDS DONT GET YOU, MAYBE THE RUST WILL:
NEW SUPERTANKER PLAGUE
By Richard Martin
it on super-rust, a virulent form of corrosion that has destroyed hundreds of
ships and could sink the oil industry.
December 7, 1999, the oil tanker Erika set sail from Dunkirk, France, bound for
Sicily, carrying 10 million gallons of heavy fuel oil. A few days later, the ship
headed south around the coast of Brittany and cruised directly into a powerful
The Erika battled swells of more than 20 feet as it steamed
across the Bay of Biscay. Soon the ship began to list, and 11-foot cracks appeared
in the deck and hull. The Erika was breaking apart. A helicopter evacuated the
crew just before the vessel split in half and sank in 400 feet of water, spreading
tarlike petroleum across more than 250 miles of the Loire-Atlantic coastline
Europes largest oil spill in two decades.
Built in Japan in
1975, the Erika was typical of todays older tankers. Sailing under the flag
of Malta, it was managed by an Italian operator and chartered by a Bahamian company
headquartered in Switzerland. Its Maltese owner was itself owned by two Liberian
firms. Deemed seaworthy by Registro Italiano Navale one of many organizations,
known as classification societies, responsible for inspecting and certifying commercial
vessels the Erika had passed every inspection over the year prior to its
The final report on the disaster, issued in January 2000
by the French investigative agency Bureau dEnquetes sur les Accidents en
Mer, concluded that severe corrosion had weakened the Erikas hull, causing
the ship to flex in the storm and eventually to fracture.
of oil moving by ship is soaring. And in traditional tankers, accelerated corrosion
is engineered right into the body of the vessel.
Erika was neither the first nor the last tanker to succumb unexpectedly to corrosion.
Each year from 1995 to 2001, an average of 408 tankers broke
apart at sea or barely escaped that fate, according to the International
Association of Independent Tanker Owners, known as Intertanko. The leading cause
was collision, but nearly as many suffered structural / technical failures
often a euphemism in industry circles for excessive corrosion and bad welds
Ships have been corroding since the late 18th century, when
wooden hulls were first covered with copper to protect against worms. Mariners
have recognized the threat to steel tankers in particular since the 1950s, and
classification societies have established a regime of inspections and maintenance
to keep corrosion at bay. But the system has failed. Ships that cost hundreds
of millions of dollars to build are falling apart on the open sea, endangering
the lives of crew members and spilling millions of gallons of oil each year.
instance, the Nakhodka went down two years before the Erika sank. This 27-year-old
tanker broke apart off the coast of Japan, spilling 1.3 million gallons of crude
and killing one sailor. The Japanese Ministry of Transport found that portions
of the ships hull had rusted 20 to 50 percent. In December 2000, the Castor,
carrying 8.7 million gallons of unleaded gasoline across the Mediterranean, developed
cracks in its deck and had to be drained of its cargo in a risky ship-to-ship
Preliminary findings in the Castor case rocked the industry.
According to the American Bureau of Shipping, the classification society that
certified the vessel, the Castor had fallen prey to hyper-accelerated corrosion
swiftly dubbed super-rust in the trade press. The ABS downgraded
its assessment to excessive corrosion in its final report, issued
this past October. Nonetheless, that document noted that the vessels steel
had disintegrated at rates of up to 0.71 millimeter a year more than seven
times the nominal rate expected by the bureau. (The ABS declined numerous
requests for an interview. David Olson, the Colorado School of Mines professor
who served as the independent metallurgist for the Castor report,
also refused to comment.)
Super-rust was initially explained as an
unprecedented phenomenon, a highly evolved form of corrosion neither foreseeable
nor preventable. The truth is less mysterious: Hyper-accelerated corrosion is
the inevitable result when unforgiving chemistry meets the harsh economics and
tangled industry politics of transporting fossil fuels.
steel from the moment the metal encounters moisture. To keep that from happening,
ship owners paint steel surfaces with corrosion-resistant coatings. The coatings
break down with age; conventional maintenance protocols dictate that tankers be
recoated periodically. If all this is done properly,
any ship should carry cargo for 30 years or so and then retire to the scrap yard
But first-class ship maintenance has become
increasingly rare in recent decades. Since the 1970s when the Erika, Nakhodka,
and Castor were built profit margins in the tanker business have fallen
steadily. Today, tankers change hands two or three times before theyre taken
out of service. Temporary owners of second or third hand ships tend
to be less interested in maintaining their vessels than maximizing the return
on their investments. Whats more, the classification societies lack the
authority to enforce rigorous standards. These nongovernmental agencies depend
for revenue on their clients: shipbuilders, owners, and operators, who can and
often do shop their business to competing societies. For instance, the Erikas
owners switched to Registro Italiano Navale after the French agency Bureau Veritas,
which had certified the ship for the previous five years, refused to overlook
its deterioration. The Erika went down just 18 months later.
far, super-rust has destroyed only old ships at the end of their useful lives,
allowing many in the industry to maintain that the problem is contained. This
complacency has become increasingly dangerous in the face of evidence that the
latest generation of tankers is even more vulnerable than its predecessors. Ever
since the Exxon Valdez ran aground in 1989 the worst spill in US history,
dumping 11 million gallons of crude into Alaskas Prince William Sound
shipbuilders have focused on constructing tankers that would be impervious to
grounding and collision. The solution has been
to wrap a second hull around the first; the Oil Pollution Act of 1990 mandates
that, by 2015, all tankers operating in the US have double hulls. This innovation
has prevented dozens of spills, but it has inadvertently propelled corrosion to
Tales of double hulls rusting far more
rapidly than expected began to circulate in the early 90s, not long after
the first such vessels entered the water. The 5-year-old Mobil tanker Eagle, for
example, spent almost three months dry-docked in Singapore in 1998, reportedly
having her cargo tanks treated for corrosion. According to Seatrends, a leading
trade magazine, the Eagle had leaked oil into the space between its inner and
outer hulls. (Contacted earlier this year, an ExxonMobil spokesperson repeated
the companys assertion that the ship docked in Singapore for routine
maintenance and that no leakage had occurred.)
Fearful of government
regulation, the shipping world has attempted, as Seatrends editor Ian Middleton
put it in a 1999 editorial, to keep a lid on such incidents. But inspections
keep turning up severe corrosion in new tankers. A 2000 Intertanko report concluded
that excessive rust is afflicting double hulls within two years of launch. Without
a serious shift in industry practice, it wont be long before the first double
hull goes the way of the Erika.
Rust arises from an intricate subatomic
dance in which waters oxygen and hydrogen atoms snatch electrons from atoms
of iron. Because saltwater conducts electricity better than freshwater, the iron
in steel oxidizes more quickly in seawater up to 0.10 millimeter per year,
as foreseen in classification-society manuals. Given enough time, this process
can eat through even the thickest hull.
The way corrosion attacks
the interior of a tanker, however, is more insidious. It can be seen most vividly
in the cargo tanks, which line up along the ships backbone beneath the deck,
and in the ballast tanks that cushion the cargo tanks along their outer edges.
In these areas, steel deteriorates at five, ten, even thirty times the nominal
In the ballast tanks, which are normally filled with seawater
when the cargo tanks are empty, water conducts electrons between plates on either
side, and between separate areas of a single plate that is, the tanks become
huge, if weak, batteries. The increased electrical activity hastens the metals
degradation. To combat the problem, shipbuilders have traditionally installed
bars of reactive metal like zinc or aluminum inside the tanks. The added metal
becomes a sacrificial anode, which corrodes in place of the ships
steel. Known as cathodic protection, this method has become less popular as paint
manufacturers have developed rust-resistant coatings over the past 20 years or
so. In the absence of cathodic protection, however, corrosion sets in when coatings
break down. Shoddy repairs can also play a role. In the
Castor, corroded plates discovered during inspections were replaced with new plates
of uncoated steel, turning the uncoated metal into a sacrificial anode. Thus,
the patches rusted even faster than the original metal had.
processes that drive ballast-tank corrosion hasten the familiar action of oxidation.
What happens in cargo tanks, on the other hand, involves more ruinous chemical
and biological forces.
At the top of the cargo tanks, the vapor space
between the oils surface and the underside of the deck traps highly acidic
gases products of the reaction between petroleum, oxygen, and water
that condense against the metal. The deck flexes at sea, causing degraded steel
to flake off the ceilings of the tanks, exposing more bare steel for the acid
to attack. Examining this area isnt easy. Scaffolding must be constructed
inside empty, unlit tanks, and even then inspectors can view only small portions
At the bottoms of the tanks, in the water that
settles under the oil, corrosive bacteria thrive. Consuming hydrocarbons, microbes
like Desulfovibrio desulferican produce acids that dissolve the tanks floors
and lower sides at rates as high as 2 millimeters per year. Some microorganisms
even feed on the coatings that protect the tanks from rust. Essentially, a tanker
is a gigantic floating petri dish for a peculiarly vicious sort of steel-eating
sludge the ultimate metallivore.
in aging single-hull vessels can be blamed on an industry in denial. In
double hulls, accelerated corrosion is engineered right into the ships themselves.
The extra layer of steel gives rust many more square feet of surface area to attack,
much of it hidden in cramped, inaccessible crawl spaces. Whats more, these
crawl spaces form an insulating layer that keeps the internal temperature much
higher than it would be in a single-hull tanker. Corrosion rates tend to double
with each 20-degree Fahrenheit increase.
the same time, manufacturing efficiencies have reduced the thickness of hulls
and decks. Guided by software modeling, designers put plenty of steel where its
needed for strength, while reducing it in the rest of the structure. The
advent of high-tensile steel stronger than conventional steel but no more
rustproof has allowed naval architects to further pare down the metal structure.
developments have led many shipbuilders to trade corrosion-resistance for lower
cost. Every ounce of steel saved in the construction of a new ship translates
into greater profits for the builder and reduced fuel bills for the owner. Between
1970 and 1990, the amount of steel used to construct a tanker declined by almost
one-fifth, according to Tankers Full of Trouble, a 1994 book by Eric Nalder based
on his Pulitzer Prize-winning Seattle Times series. Modern
tanker walls are only 14 to 16 millimetres thick, compared with 25 millimeters
a generation ago. Assuming a microbial corrosion rate of 1.5 millimeters a year,
rusted-out pits would reach halfway through those hulls in five years.
without a spill, the consequences of an internal breach leaking oil into a double
hull could be catastrophic. Asked what might result, shipbuilding consultant Rong
Huang gives a one-word answer: Explosion.
All ships look old unless
theyre freshly painted. At the Avondale Shipyard, upriver from New Orleans,
the only unblemished metal surfaces are rails that support rolling dockside cranes
and the gleaming blue sides of the state-of-the-art tanker Polar Resolution. Every
other steel surface in the yard is dusted with flash rust, a ruddy patina that
appears almost as soon as the steel is exposed to air. This superficial oxidation
is sandblasted away before the metal is painted and coated. Some surfaces, however,
never get coated at all. These unprotected areas invite the risk of destruction
Contracted by Polar Tankers, a division of Phillips
Petroleum, the Polar Resolution is one of four $230 million ships designed for
the iceberg and reef-strewn run from Valdez, Alaska, to Puget Sound. The 895-foot
vessel has not only a two-layer hull but duplicate engine rooms, navigation systems,
and propellers. Its 12 cargo tanks hold 42 million gallons of oil. When its sister
ship, Polar Endeavor, set sail last spring, Professional Mariner magazine named
it Ship of the Year.
A series of ladders and stairways descends steeply
to the floor of the Polar Resolutions empty cargo tank number five. The
walls rise 100 feet to the main deck. A band of light streams from the hatch high
above. From the inside, the tank is like a vast steel cathedral, a shrine to mans
thirst for oil.
The tank floor is covered with epoxy.
But overhead, the vapor space is uncoated contrary to classification-society
This expanse of bare metal is a stark emblem
of the industrys failure to face up to the hazard of corrosion. With each
disaster or near-disaster, authorities have launched an investigation. When corrosion
has been implicated, the result has been a litany of recommendations that hardly
varies from year to year: Coat the vulnerable surfaces of the ballast and cargo
tanks, inspect them frequently, and remove substandard tankers from service. But
these guidelines are honored mostly in the breach. According to the ABS report
on the Castor, the ships last inspections failed to adequately represent
the condition of the vessels structure. In other words, the investigators
missed the damage.
Supertankers are the
biggest moving structures ever built, yet the system for constructing, inspecting,
and certifying them is a relic of the 19th century.
time, the classification societies were adjuncts to the marine insurance business.
Today, they call themselves the self-regulating arm of the shipping world; the
avowed mission of the ABS, for instance, is to serve the public interest
as well as the needs of our clients by promoting the security of life, property,
and the natural environment. In practice, the societies serve the shipowners.
The leading organizations, which include the ABS, Lloyds Register in London,
and Det Norske Veritas of Norway, are staffed by conscientious experts, but they work within a system where no one is answerable for the condition of
the ships. There is no FAA for tankers.
the tanker industry is overrun with so many holding companies, limited-liability
partnerships, and owners-of-record that even determining who bears ultimate responsibility
for a ship can be difficult. Authorities investigating the Erika found the owners
capital structure so opaque that it was nearly impossible to figure out who controlled
the company. Following the inquiry, Paul Slater, chair of shipping conglomerate
First International Group and a member of Intertankos Communications Committee,
declared the current inspection system monstrously outdated.
Most American tax payers are rarely aware of where their taxes go and some goverment weld - bld rework costs can be extraordinary.
to the program office the LPD 17 Amphibious Transport Dock, which was delivered
to the Navy in July 2005, experienced numerous quality problems
of varying degrees that significantly impacted the ships mission. These problems contributed to a delay of 3 years in the delivery of the ship and a cost increase of $846 million.
In June 2007,
the Secretary of the Navy sent a letter to the Chairman of the Board of Northrop
Grumman expressing his concerns for the contractors ability to construct
and deliver ships that conform to the quality standards maintained by the Navy
and that adhere to the cost and schedule commitments agreed upon. Northrop Grummans
Chairman acknowledged that the company was aware of the problems and is working
on improving its processes.
LPD 17 encountered a problem with the isolators on titanium piping. The isolators
are used to separate different types of metals to keep them from corroding. The
problem was discovered in 2006, about a year after the launch of the first ship.
According to DOD program officials, the titanium piping is used throughout the
ship because it is lighter than the traditional copper-nickel piping and has a
longer service life. However, it has not been used much in naval surface ships
or by the American shipbuilding industry, and therefore required new manufacturing
and installation processes. According to the program office, these processes were
being developed as Northrop Grumman Ship Systems was building the ship. In addition,
designs for the piping hangers, which hold the piping in place, as well as tests
of the isolators were subsequently delayed. When the titanium piping on the ship
was changed, the hanger design had to be modified as well. The final hanger design
was not completed until about 90 percent of the titanium piping was already on
the ship, which resulted in additional rework and schedule delays.
from Ed. Welding Titanium. It would have been an easy task with TIP TIG which was available at this time.
ship alsp encountered problems with faulty welds on P-1 piping
systems, a designation used in high-temperature, high-pressure, and other
critical systems. This class of piping is used primarily in hydraulic applications
in engineering and machinery spaces. P-1 piping systems require more extensive
weld documentation than other pipes as they are part of critical systems and could
cause significant damage to the ship and crew if they failed. Welds of this nature
must be documented to ensure they were completed by qualified personnel and inspected
for structural integrity. Further investigation revealed that weld inspection
documentation was incomplete. As a result, increased rework levels were necessary
to correct deficiencies and to re-inspect all the welds. Failure to complete this
work would have increased the risk of weld failure and potentially presented a
hazard to the ship and crew. According to the program office, a contributing factor
was turnover in production personnel and their lack of knowledge on how to complete
the proper documentation.
Note from Ed. If people
are not doing their job, not qualified to do the job, it's time to hire qualified managers who can rectify these situations.
THE FOLLOWING IS A REASON YOU CANNOT APPLY DOUBLE
TO SHIP OR OIL PLATFORM WELDS:
AS THIS NEXT ARTICLE INDICATES. EVERY WELD SHOULD BE CONSIDERED A CRITICAL
Authors KITUNAI, Yoshio
(Japan Crane Association)
KOBAYASHI, Hideo (Yokohama National University)
March 27th, 1980, the semi-submersible platform Alexander
Kielland suddenly capsized during a storm in the North Sea, because one of its
five vertical columns supporting the platform was broken off. 123
workers among the 212 people on board were killed in the accident.
investigation showed that a fatigue crack had propagated
from the double fillet weld near the
hydrophone mounted to the tubular bracing D6. As a result, the five other tubular
bracings connecting to the vertical column D broke off due to overload, and the
column D became separated from the platform. Consequently, the platform became
unbalanced and capsized. After the accident, the offshore design rules were revised
and some countermeasures were added to maintain a reserve of buoyancy and stability
for a platform under a storm.
Cause (1) Fracture features
circular hole was introduced to the underside of the D6 bracing, and a pipe, which
is called a hydrophone, was mounted into the circular hole by welding. The hydrophone
was 325 mm in diameter with a 26 mm wall thickness. The hydrophone was welded
using a double fillet weld with a weld throat thickness of 6 mm. A drain of the
bracing D6 had to be installed at a location 270 mm away from the hydrophone.
a result of examination of the welds of the D6 bracing, some cracks related to
lamellar tearing were found in the heat affected zone (HAZ) of the weld around
the hydrophone. Traces of paint coinciding with the paint used on the platform
were recognized on the fracture surface of the fillet weld around the hydrophone
in the bracing D6.
The paint traces show that the cracks
were already formed before the D6 bracing was painted. Examination of the
fracture surface also showed that the fatigue cracks propagated from two initiation
sites near the fillet weld of the hydrophone to the direction circumferential
to the D6 bracing. Moreover, the fatigue fracture surface occupied more than 60%
of the circumference of the D6 bracing (Fig. 7), and beach marks were formed on
the fracture surface, which was about 60 to 100 mm away from the hydrophone. Striations
with spacing of 0.25E-3 to 1.0 E-3 mm were observed in patches on the fracture
surface of the D6 bracing.
(2) Characteristics of the welds of the hydrophone. Considering
of the importance of the strength of the D6 bracing, welding of the drain into
the bracing was carried out carefully according to the design rules. In the case
of the installation of the hydrophone, however, a circular hole was made on the
D6 bracing by gas cutting, and the surface of the hole was
not treated by some process, such as a grinding. After cutting, a pipe,
which was made by cold bending and welding using a plate with 20 mm thickness,
was mounted into the hole of the bracing, and the pipe was attached by welded
around the hole by double fillet welding with a throat thickness of 6 mm.
the hydrophone was installed by welding, the weld defects, such as incomplete penetration,
slag inclusion, and root cracks, were introduced in the welds, because of the
poor gas cutting and welding practices. Moreover, lamellar
tearing related to inclusions in the material used was found near the HAZ of the
hydrophone. The stress concentration factor, Kt, of the fillet weld of the hydrophone
was in the range of 2.5 to 3.0, which is higher than the average value of Kt of
1.6 for a fillet weld performed under normal conditions.
Chemical composition and mechanical properties of materials
The chemical composition
of the materials was found to be within the specified limits. A comparison of
the mechanical properties between the specification and the test results for the
fractured materials is shown in Table 2. The yield strength of the D6 bracing
in the longitudinal direction is slightly lower than the specified minimum values. In case of the hydrophone, the
Charpy impact energy is lower than the required value of 39 J at -40 C. Moreover,
the reduction of area of the hydrophone for the through-thickness direction is
markedly reduced because of the large amount of weld inclusions.
(1) Although the D6 bracing was
one of primary components of the platform, little attention was given to the installation
of the hydrophone into the bracing. Hence, a crack with
a length of about 70 mm was introduced in the fillet weld around the hydrophone,
before the D6 bracing was painted.
(2) Fatigue cracks propagated
from two initiation sites near the fillet weld of the hydrophone in the direction
circumferential to the D6 bracing at the early stage of the life of the platform.
The five other bracings connected to the column D broke off due to overload, and
the column D was separated from the platform. Consequently, the platform became
unbalanced and capsized
(4) Inspection of the D6 bracing had not been carried
This is a partial report found on the web and it enpahasizes that all welds should be considered critical.
Date August 10, 2001. Revised Nov 2001.
Please never let the Self Shielded flux cored
process get into your facility.
Buildings, Earthquakes and
welds that should not have failed
This story has it all. Lincoln
Electric and their incredible defence of their unsuitable self shielded flux cored weld consumables. Politicians and corporate management
and the common lack of accountability The
selection by inexperienced California engineers of questionable weld consumables for the majority of the construction projects. Cleveland
voters sending donations to California politicians. USA Tax payers stuck with the welding related bills. Lobbyist,
Lincoln and FEMA connections. A generous grant of millions to a company
that did not ask for it. The possibility of future buildings designed to with
stand an earth quake waiting to collapse and let's not forget, the deaths that
occurred and the casualties that will occur in the next L.A earthquake.
If this was a movie I would call it;
"The Fox who
was asked to guard the Lincoln Hen House"
Note: The self shielded flux cored wire consumables recommended by Lincoln and
the Chrysler corporate weld engineer, have cost the Auto / Truck Industries millions each year on unnecessary
weld rework, rejects and robot down time..
auto / truck Self Shielded flux cored wire problems, click here.
The Beijing Olympic Birds Nest.
WILL IT BE A BIRDS NEST OR A SPIDERS
WEB FOR CHINEASE SPECATORS?
by Ed Craig.
Aug. 2. 2008.
Which has more value, great design or sound welds? The five hundred million dollars, Beijing Olympic stadium, is
wrapped with a unique high strength steel box cocoon that weighs approx. 45,000
tons. At the end of July, two weeks before the 91000 seat stadium was ready to
host the 2008 Olympics, I watched a Discovery Channel program about the stadium
construction. The steel bird's nest design is without question a wonder
to behold, however having a slight interest in fabrication and welding you know
where my focus was and I could see the welds were a mess.. Click here for the
rest of this story.
WELD SHOPS WILL NOT
CHANGE WHEN MANAGED
BY MANAGERS OR
ENGINEERS WHO DON'T BELIEVE
IN WELD PROCESS
CONTROLS AND OWNERSHIP.
course there are a few ship and oil platform yards and large scale weld projects that will be using best weld practices and in full control of the weld
processes utilized, however in the majority of large scale, steel construction facilities,
lack of management - engineering process ownership and weld design apathy is like a cancer that for decades has been spreading throughout this
important global industry.
Living with poor weld practices, lack of process controls and manufacturing standards in which design tolerances have no meaning is so common that many managers
would do well to place a large sign in front of their ivory towers that states. "
"Please dont come into this office with the idea
that myself and fellow managers and engineers should actually take ownership of the weld equipment and processes in this organization, that's not the way we do it, and I don't see the need to change our our hands off status quo".
THE Good News: Because things are so bad in many global weld shops, there is a remarkable opportuinty for dramatic weld quality - productivity improvements. For management that can get there head out of the sand, this means that there is a great opportunity to provide extensive weld labor, equipment and consumable costs savings.
For those that
want change, an important tool that can enable the weld results you desire is my Best MIG and Flux Cored Weld
Practices and Weld Process Controls, Self Teaching and Training resources.
you are teaching your self, or providing weld process control training for others,
the following resources are the key to attaining MIG and flux cored weld process
Item.1. The Book: "A Management & Engineers Guide To MIG
Quality, Productivity & Costs"
2. A unique robot
MIG training or self teaching resource.
Robot MIG Welds from Weld Process Controls".
unique MIG training or self teaching resource.
Manual MIG Weld Process Optimisation from Weld
4. A unique flux cored training or self teaching resource.
"Optimum Manual and Automated Flux Cored Plate and
you visited Ed's Bad Weld Sections?
www.weldreality.com is the world's largest web site
MIG - TIG - FCAW process controls..
TiP TiG the world's most important weld process for
pipe and alloy welds can be viewed at www.tiptigusa.com