<
2003. E-mail Question: Ed, my company is
Hayes Lemmerz. 
We
are a global supplier of car and truck wheels. We use the Pulsed MIG process.
Since we introduced the Miller Maxtron and Miller
Invision equipment to our automated, MIG weld production lines, we have
had extensive, weld production and rework issues.
The
typical wheel weld problems that we experienced with the Miller pulsed equipment
have been;
[1] welds skipping, resulting in weld areas
that contain unacceptable and inconsistent thin welds,
[2] missed welds,
[3] welds with inconsistent weld penetration,
[4] weld globs,
[5] unexplained weld porosity,
[6] Inconsistent weld
surface appearance,
[7] inconsistent weld undercut,
[8] numerous arc start,
crater and weld tie in issues,
[9] numerous wire burn back issues,
[10]
extensive weld equipment break downs.
Ed's Reply.
In
any weld shop, a priority has to be that those responsible, the owners, managers,
engineers, have the ability to select and evaluate
weld equipment and weld transfer modes that are
critical for their daily production.
Around
2000, at the request of the Haynes management, I evaluated the pulsed MIG weld
issues and the root cause of their extensive weld issues was no surprise.
While
Miller had a reputation
for building the world's best CV MIG equipment, the Miller pulsed equipment should
have never left their product development lab. Its difficult for me to understand
why the responsible corporate executives at Miller let these erratic performing
pulsed MIG power sources leave their factory. Perhaps the Miller executive like
the Haynes management simply lacked weld process expertise.
For
me the e weld solution for the Haynes weld problems was simple. I switched the
pulsed modes off and changed the weld procedure to the conventional spray transfer
mode. It was clear from the optimum, consistent spray welds produced, that switching
the pulsed mode off would be a highly cost effective solution to the weld quality
and productivity issues.
I followed up with an extensive report on the
root causes of the wheel weld issues and all
the evidence was presented to the Hayes management.
I
also provided an actual weld demonstration and delivered four hours of consistent
wheel weld quality and production with no weld rework. Just
in case anyone at the plant has an interest, I also increased the hourly MIG weld
production rate by 20%. I provided the process control requirements and offered
a four hour process control training program that would get the plant back to
it's 
required
weld productivity and quality.
How did the Haynes management and engineers
receive the weld report? Unfortunately the "hands off
- we have surrendered management", had no one who would step up to the plate
take ownership or responsibility.
WHEN
YOU GIVE PROCESS LOGIC TO MANAGEMENT AND ENGINEERS THAT LACK PROCESS EXPERTISE,
IT'S SOMETIMES DIFFICULT FOR THEM TO REACT, TAKE RESPONSIBILITY AND GET OUT OF
THEIR COMFORT ZONE.
Hayes
declared bankruptcy a few years later. I think they are still in business. If
so, I hope they learnt a valuable lesson and hired some managers and engineers
that understand the definition of equipment ownership and weld management.
THREE
HUNDRED AND SIXTY DEGREES OF INCOMPETENCE.
WHEN
YOU THINK ABOUT IT, THE INCOMPETENT MANAGEMENT AT THE WHEEL COMPANY SHOULD HAVE
SUED THE INCOMPETENT MANAGEMENT AT MILLER FOR SELLING THEM THE INCONSISTENT, WELD
EQUIPMENT THAT HAD DRAMATIC COST CONSEQUENCES TO THEIR INCOMPETENT ORGANIZATION.
LETS GET BACK TO WELD REALITY. TO SUE MILLER
OR ANY WELD EQUIPMENT MANUFACTURER THAT PROVIDES WELD EQUIPMENT THAT CAN BE PROVEN
TO BE THE CAUSE OF COSTLY WELD QUALITY OR PRODUCTIVITY ISSUES, THE PLANT MANUFACTURING
MANAGEMENT WOULD FIRST HAVE TO SHOW AN INTEREST IN THE WELD PROCESSES USED IN
THEIR PLANTS AND AT LEAST HIRE SOMEONE WITH THE FUNDAMENTAL ABILITY TO UNDERSTAND
THE ROOT CAUSE OF THEIR DAILY MANUFACTURING WELD ISSUES.
THREE
HUNDRED AND SIXTY DEGREES OF INCOMPETENCE.
OF COURSE ONCE THE WELD MANAGER WAS CAPABLE OF UNDERSTANDING THAT THE THE NEW
PULSED WELD EQUIPMENT WAS A ROOT CAUSE OF THE WELD ISSUES IN HIS PLANT, HE WOULD
THEN REMEMBER THAT HE WAS THE ONE WHO PLACED HIS SIGNATURE ON THE PURCHASE ORDER
FOR THE SAME USELESS PULSED EQUIPMENT.
IT'S
NOW 2008: I HAVE EVALUATED THE BEST USA, EUROPEAN AND JAPANESE PULSED EQUIPMENT,
WOULD I USE THE LATEST PULSED MIG EQUIPMENT FOR THE AUTOMATED CARBON STEEL WHEEL
APPLICATION? THE ANSWER IS "NO".
I WOULD STILL USE THE PROCESS THAT
PROVIDES THE MOST CONSISTENT WELD TRANSFER. SPRAY TRANSFER.
<
2008: THIS OLD FART WILL USE PULSED
WHERE IT PAYS THE BILLS.
FOR
THOSE OF YOU THAT ARE LESS THAN 40 YEARS OF AGE AND THINK I AM AN OLD FART STUCK
IN A 1970 MIG EQUIPMENT TIME WARP. WELL I DO EAT A LOT OF
BEANS SO AM AN OLD FART, BUT I HAVE NEVER BEEN STUCK IN A WELD TECHNOLOGY
TIME WARP.
YOU MAY BE SURPRISED TO KNOW THAT IN 2006
I WAS THE WELD
MANAGER WITH A COMPANY THAT EACH YEAR USES APPROX. ONE MILLION POUNDS OF STAINLESS
AND INCONEL WELD WIRES ON VERY DIFFICULT, PULSED MIG, OVERLAY,
WATER WALL, BOILER APPLICATIONS.
THESE , HIGH DEPOSITION, HIGH ALLOY,
ASME CODE BOILER PULSED APPLICATIONS, ACHIEVED UNIQUE WELD BENEFITS FROM THE PULSED
MIG PROCESS.
HOWEVER IN A FEW MONTHS OF WELD PROCESS DEVELOPMENT FOR WSI
, I CAME UP WITH A NEW PULSED MIG PROCEDURE, ( PHOTO) THAT WAS PATENTED BY WSI
IN 2007. (SEE CLAD SECTION). THESE INCONEL CLAD WELDS
WERE MADE IN THE VERTICAL POSITION ON WATER WALL BOILER TUBES. THESE WELDS , WOULD
NOT BE POSSIBLE WITH THE TRADITIONAL SPRAY TRANSFER MODE. 
MY
WIFE WOULD AGREE THAT
I AM OLD FART, HOWEVER I HAVE
BEEN AROUND THE WELDING BLOCK A FEW TIMES.
I KNOW MANUFACTURING MANAGEMENT
AND I KNOW WELD SHOP CULTURE.
I HAVE PROVIDED MIG AND FLUX CORED WELD PROCESS IMPROVEMENTS,
WITHOUT THE
RECOMMENDATION OF NEW EQUIPMENT OR THREE PART GAS MIXES TO MORE THAN 1000 COMPANIES,
IN 12 DIFFERENT COUNTRIES.
AS
I TRAINED MORE THAN 2000 WELD SALESMEN I
ALSO SHOULD KNOW WELD SALESMEN AND WELD MARKETING MANAGEMENT,
I
STARTED MIG WELDING AT MASSEY FERGUSON IN THE EARLY 1960s. I WROTE MY FIRST MIG
PROCESS CONTROL ARTICLES IN THE LATE 1970s AND WHILE EXITED AT THE FUTURE PULSED
MIG PROSPECTS, WROTE MY FIRST PULSED MIG ARTICLE FOR THE WELD JOURNAL IN THE EARLY
1980s.
DURING THE LAST THREE DECADES I HAVE WRITTEN FOUR BOOKS
ON MIG PROCESS CONTROLS AND HAD MORE THAN 30 MIG AND FLUX CORED PROCESS CONTROL
ARTICLES PUBLISHED. I WAS THE MARKETING, PRODUCT OR TRAINING MANAGER FOR FOUR
OF THE WORLD'S TOP SIX WELD EQUIPMENT AND CONSUMABLE SUPPLIERS.
IN
THE FIRST FOUR MONTHS OF APRIL 2008, I WILL HAVE BEEN TO SIX DIFFERENT COUNTRIES
TO IMPROVE MIG / FCAW WELD QUALITY AND PRODUCTIVITY. AT ALL THE COMPANIES I VISIT
I WILL PREACH THE REQUIREMENTS OF MANAGEMENT / ENGINEERS PROCESS OWNERSHIP, BEST
WELD PRACTICES AND PROCESS CONTROLS.
WHAT THE WELDER NEVER SEES.
AS
THE ABOVE 2004 MIG PULSED CURRENT / VOLTAGE GRAPH INDICATES, A PRIMARY ISSUE WITH
THE PULSED MIG WELDING PROCESS IS NOT WITH THE UNIQUE PULSED WELD TRANSFER MODE,
IT'S WITH THE INCONSISTENCY OF THE PEAK TO BACK GROUND PROCESS AND INCONSISTENCY
OF THE PERFORMANCE OF THE PULSED WELD EQUIPMENT.
AS
THEIR CAN BE ARE TREMENDOUS COST 
CONSEQUENCES
FOR ERRATIC PERFORMING WELD EQUIPMENT, THOSE IN WELD MANAGEMENT SHOULD ASK, DID
THE MIG EQUIPMENT MANUFACTURERS ACT
IN A RESPONSIBLE MANNER?
<2008.
HOW MANY OF THE MAJOR PULSED EQUIPMENT MANUFACTURERS INFORMED THEIR CUSTOMERS
ABOUT THE NUMEROUS ELECTRONIC AND PROCESS INSTABILITY ISSUES THEY WERE HAVING,
OR ARE STILL HAVING WITH THEIR ERRATIC PULSED EQUIPMENT?
DURING THE LAST TWO DECADES,
MOST OF THE ERRATIC PULSED MIG
POWER SOURCES REQUIRED NUMEROUS
E-PROM, CIRCUIT BOARD AND ELECTRONIC CHANGES,
YET AS FAR AS I AM AWARE, NO PULSED MIG POWER SOURCE RECALLS WERE EVER ISSUED
FROM ANY GLOBAL, MAJOR WELD EQUIPMENT MANUFACTURER.
THE
BOTTOM LINE WAS MANY GLOBAL WELD SHOP PAID A PREMIUM PRICE FOR PRODUCTS THAT PROVIDED
ERRATIC WELD PERFORMANCE AND NO STEEL APPLICATION BENEFITS.
Traditional
CV MIG equipment can last 10 to 20 years and the weld equipment repair costs carried
out by the plant's electrician are typically less than $1000. Many of the companies
who purchased pulsed MIG equipment have paid $2000 to $5000 for pulsed weld equipment
repairs before the equipment was 48 months old.
2008:
IT WOULD BE INTERESTING TO FIND OUT;
[]
WHAT PERCENTAGE OF PULSED MIG EQUIPMENT LASTS BEFORE IT'S WARRANTY EXPIRED?
[]
WHAT THE AVERAGE LIFE OF A PULSED POWER SOURCE IS?
[] WHAT THE AVERAGE
REPAIR COST IS FOR PULSED EQUIPMENT?
[]
HOW MANY COMPANIES TODAY WILL PURCHASE AN ADDITIONAL PULSED
POWER SOURCE SO THEY HAVE A SPARE?
[] HOW MANY ELECTRICIANS WILL EVEN ATTEMPT
TO REPAIR A PULSED MIG POWER SOURCE.
It's
a sad reality that many companies will pay more than $4000 for pulsed MIG weld
equipment repairs. That's more than the cost of a new CV MIG power source and
wire feeder. That's the CV power source that can provide optimum weld quality
that will meet any weld code requirement. That's the power source that should
last one to two decades without repairs.
What helped the low durability, costly, erratic
pulsed MIG process become so popular in the last two decades?
[] IN CONTRAST TO TRADITIONAL CV 
EQUIPMENT,
WITH PULSED EQUIPMENT, THE EQUIPMENT MANUFACTURER CAN REDUCE THE STEELS / ALLOY
COSTS AND REDUCE THE LABOR COSTS ASSOCIATED WITH BUILDING THE CV EQUIPMENT.
[]
ALL EQUIPMENT MANUFACTURERS ARE AWARE THAT WHEN YOU ADD
ELECTRONIC BELLS AND WHISTLES YOU CAN DRAMATICALLY INCREASE THE EQUIPMENT PRICES.
[]
WHAT TURNS THE SALESMAN ON? IN CONTRAST TO SELLING CONVENTIONAL
LOWER COST CV EQUIPMENT THAT SELLS IN THE $2000 TO $4000 RANGE, THE
APPROX. 6000 WELD SALES PERSONNEL IN NORTH AMERICA HAVE A MUCH GREATER INCENTIVE
FOR SELLING PULSED EQUIPMENT THAT TYPICALLY COST THEIR CUSTOMERS ONE TO THREE
FOUR HUNDRED PERCENT MORE THAN A REGULAR MIG POWER SOURCE.
[]
WHEN YOU SELL EQUIPMENT WITH A SHORT LIFE SPAN, YOU WILL BE ABLE TO SELL MORE
EQUIPMENT.
PRACTICAL
PULSED MIG BENEFITS ON SPECIFIC CARBON AND STAINLESS ROBOT
APPLICATIONS:
Spray transfer can be too hot for some steel applications
and there are numerous robot applications that will use high current short circuit
or globular transfer, both of which are outside the optimum weld 
parameter
range. Typically these steel applications are in the
2 to 4 mm range and welded
with an 0.045 (1.2 mm) wire.
THE
USE OF THE PULSED EQUIPMENT AND 0.045 WIRE AND THE PULSED MODE ON SPECIFIC AUTOMATED
2 to 4 mm STEEL APPLICATIONS COULD ALLOW SLIGHTLY
HIGHER WELD DEPOSITION RATES THAN THE SHORT CIRCUIT OR LOW END SPRAY WELDS. HOWEVER
ONE ALSO NEEDS TO LOOK AT THE BENEFITS OF SHORT CIRCUIT BRIDGING GAPS AND THE
USE OF SPRAY TRANSFER WITH A SMALLER DIAMETER MIG WIRE LIKE THE 0.035 OR 0.040
(1-1.1mm) WIRES.
IF
IT SOUNDS COMPLEX, SHOULD IT BE IN A WELD SHOP THAT
FOR 20 YEARS HAS PLAYED
AROUND WITH THE 2 CONTROL
TRADITIONAL CV, MIG POWER SOURCE?
SALES
DRIVE WELD PROCESS ADJECTIVES AND INEXPERIENCED WELD
MANAGEMENT INFLUENCED THE GROWTH OF A WELD PRODUCT THAT FOR TWO DECADES PROVIDED
LIMITED WELD BENEFITS:
DURING
THE LAST TWO DECADES OF SLOW PULSED EQUIPMENT DEVELOPMENT, (THANK GOD COMPUTERS
EVOLVED AT A MUCH FASTER RATE), MOST PULSED MIG EQUIPMENT WAS PROVEN TO BE USELESS
AND UNSTABLE FOR MANUAL MIG OR HIGH SPEED ROBOT WELDS ON CARBON / LOW ALLOY STEEL
APPLICATIONS. YET IN THIS TIME FRAME, THE MAJORITY OF NORTH AMERICAN WELD SHOPS
COULDN'T BUY THEM FAST ENOUGH.
IS
THIS WHAT YOU WANT TO SEE AND HEAR IN YOUR SHOP? This unique $12.000 MIG
power source called called XMIG, is controlled by a palm
pilot, offers artificial intelligence with adaptive SYNERGIC controls.
XMIG provides millions of wave form variations. With XMIG You get Fuzzy, weezy,
woozy logic and Pulsed on top of a turbo pulse. Also included in the introductory
low price, is a modified short circuit mode called MSC - STP. Your new, XMIG power
source can also be hooked up to your cell phone, or I-Pod and controlled if you
feel the need with the palm pilot through the ethernet.
XMIG comes with
a two week warranty, (check small print for warranty clauses) and no return policy.
To
order this unique MIG equipment, contact the industry leaders in weld technology,
at AskaWeldSalesman.com
Ed made this manual, optimum, spatter free MIG spray weld with
a $2000 traditional CV. MIG power source that had no electronics.
The
low cost, durable, 400 amp, CV MIG power source I utilized on
the above weld,
was developed four decades before wave
forms and fuzzy logic became MIG weld
buzz words.
THE
MORE COSTLY THE PULSED MIG EQUIPMENT,
THE
MORE EXPENSIVE THE MIG WELD
EQUIPMENT REPAIRS.
WHEN THE MAINTENANCE SUPERVISOR SAW THE NEW PULSED MIG EQUIPMENT,
HE REALIZED HIS ELECTRICIANS WERE NOT CAPABLE OF FIXING THE MIG EQUIPMENT.
THE
SUPERVISOR HAD A DIFFICULT TIME FINDING A LOCAL EQUIPMENT REPAIR SHOP THAT COULD
PROVIDE THE NECESSARY ELECTRONIC PULSED WELD EQUIPMENT REPAIRS WITH A QUICK TURN
AROUND. TO MAINTAIN HIS DAILY ROBOT WELD PRODUCTION, HE
DECIDED TO ORDERED ANOTHER 2 UNITS
AS SPARES?
To purchase wave forms you don't need, how
much will your company this year budget for those pulsed MIG weld equipment repairs?
Two weeks after the three year old warranty has elapsed on
that pulsed power source, you could end up with a MIG weld power source repair
bill that is in the $3000 to $5000 range. The bottom line after that expensive
repair, that three year old pulsed power source is the equivalent of a 10 year
old car and you know what direction that's heading.
TWO
QUESTIONS YOU COULD ASK
YOUR PULSED EQUIPMENT MANUFACTURER.
YOU ADMIT YOUR PULSED EQUIPMENT HAS HAD MANY ELECTRONIC ISSUES, YET I CANNOT RECALL
YOU INFORMING US ABOUT THOSE FAULTS OR PROVIDING A WELD EQUIPMENT RECALL.
AS WE RESENT BEING A TEST LAB FOR YOUR EVOLVING, ERRATIC WELD EQUIPMENT, WOULD
IT BE POSSIBLE FOR YOU TO THOROUGHLY TEST YOUR NEXT NEW MIG EQUIPMENT BEFORE YOU
PRESENT IT TO WELD SHOP?
A
minor detail to some.
Pulsed MIG Weld Current and Voltage:
PULSED
MIG EQUIPMENT PERFORMANCE:
As
this MIG volt / amp graph of a 2004 PANASONIC pulsed MIG POWER source indicates,
the
weld current (black)
and voltage (red)
are anything but stable.
Arc and weld energy stability
with pulsed weld equipment is something that is a concern for any weld individual
that understands the importance of attaining consistent
weld energy for consistent weld fusion.
Excessive pulsed arc weld
current and voltage fluctuations and common pulsed arc plasma instability, especially
in the SYNERGIC modes, when added to pulsed arc length sensitivity and peak to
back ground parameter changes, all can add to robot high
speed, arc / weld instability. Even if you don't understand the pulsed
process, you have to be able to figure out the concern for attaining consistent
weld transfer and optimum fusion, especially on high weld speed applications and
on steel and stainless parts > 6 mm.
AS
YOU VIEW THESE TWO SIMPLE MIG FILLET WELDS,
WHICH WELD LOOKS THE BEST?
On the left, we have a manual, pulsed fillet weld. I made this
weld at a tier one company in the USA using a E70S-3, 0.045 (1.2mm) wire and 90
Ar - /10% CO2 mix. The power source was a Lincoln pulsed Power Wave and it cost
approx. $11000. The fillet weld I produced on the
right, is made with the exact same technique, the same wire, gas and wire feed
rate. This weld was made with the spray transfer mode, using a conventional, Lincoln
CV power source that cost approx. $2500.
I
used exactly the same weld technique for both the above welds and provided the
same 450 ipm wire feed rate. The
450 ipm is a common spray wire feed setting used for robot welds on part >
6 mm.
I set a weld voltage / arc trim length that was
optimum for both welds as evident by the lack of weld spatter for both welds on
the untouched parts.
The
inconsistent, parameters from the pulsed steel program provided an agitated,
sluggish, slightly irregular weld surface with weld toe irregularities, (slight
scalloped edge).
In contrast and as I expected, the conventional, constant
voltage, spray weld shows uniform weld energy as indicated in the spray weld surface
and fusion lines. Note
the higher energy in the spray weld heat affected zones. You can be sure
that a macro of both welds would reveal the more fluid and consistent spray weld
provided superior side wall fusion, an important attribute on parts > 6 mm.
Traditional
spray transfer with 0.035 (I mm) and 0.045 (1.2 mm) wires, can offer unique arc
stability and fusion advantages for high speed welds.
WHAT
GOES "AROUND" COMES AROUND.
We
can all learn learn from the welding past.
Around 2000, I was asked to rectify
high speed torque converter welds for a General Motors plant.
The GM plant had installed new 
manufacturing
lines to automatically MIG weld torque converters. For the high volume production
lines, GM had purchased new Lincoln Power Wave pulsed
MIG equipment.
Typically torque converter lines, will utilize two or three stationary MIG guns
per welding station.
The torque convertors parts are delivered to the
weld stations by conveyors. The round parts then rotate with the MIG welding guns
stationary. The parts required 3/16 (4.8 mm) horizontal lap welds.
GM
like Ford and Chrysler has been a company that rarely shows management / engineering
ownership of the weld equipment in it's plants. The world's
largest torque manufacturer had to ask the people who make weld equipment how
to place a MIG weld on a round part. Influence by salesmanship or something
other than process knowlege, GM purchased the costly pulsed Power Wave MIG equipment
and ran the MIG pulsed weld parameters at the recommendations made from Lincoln
Electric.
The pulsed MIG welding issues from the
brand new welding lines were;
[1]
pulsed welds skipping
resulting in weld areas that contain thinner, partial welds, weld
globs or missed welds requiring weld repairs,
[2] pulsed weld
with inconsistent pulsed weld penetration, causing
rejects from the leak tests,
[3]
excess weld porosity,
[4]
Inconsistent weld surface appearance,
[5]
weld undercut,
[6] extensive, pulsed
arc starts, craters and weld tie-in issues,
[7] numerous wire burn back
to contact tip issues,
[8] extensive pulsed
weld equipment break downs.
Note
from Ed. Read the Haynes wheel problems (above) using Miller pulsed equipment
and you see similar issues.
The
Lincoln equipment, pulsed arc weld instability at the recommended pulsed wire
feed settings, caused extensive
weld quality issues, rework and productivity issues for GM. The annual weld rework
and loss of productivity losses for this plant would be in the range of one to
two million dollars.
At the GM plant, the
new Lincoln pulsed PowerWave equipment did not get of on a good
start with the maintenance personnel, half
the new Lincoln PowerWaves had to be replaced in the first 12 months.
From my perspective, getting to the root cause of the weld issues and providing
the weld solution was straight forward. As I have done on many occasions, I switched
the Lincoln Power Wave "pulsed mode off".
I changed the weld wire diameter, and set new, optimum, spray weld parameters.
In a three day test period in which hundreds of parts were welded and pressure
tested for leaks, my spray weld procedure and the process controls I provided,
eliminated the daily weld rework of 8% to zero. In
the week I was at the plant I also gave GM a nice production bonus by increasing
the daily production rate by 27 percent.
GM
MANAGEMENT AND PROCESS APATY: In the week I was in the plant making the
changes and doing the tests, none of the GM managers from the front office showed
any interest in what was being achieved by a little human "weld process expertise".
I
can only assume these shy,hands off managers had low expectations as they thought
they had already talked to the welding experts when dealing with Lincoln and the
integrator, the two companies responsible for their weld
issues.
By the way for saving GM millions at least 2 million
dollars each year, I received check for approx. $5000, expenses included.
It
was 2004. Another Pulsed Problem and I was
wondering, when will MILLER get
it right?
2004:
This time my pulsed MIG application was a major
manufacturer of stainless exhaust coupling and flexible fittings as used in the
auto / truck industry. The tight tolerance, stainless parts, are rotated in an
automated welding machine with the single MIG gun stationary. As indicated in
the photo, the stainless MIG welds were made inside the flange. With these parts
I was again provided the opportunity to evaluate pulsed
MIG versus traditional spray.
To weld the stainless coupling parts, the manufacturer had selected Miller
Invision
pulsed MIG equipment. The weld transfer mode utilized was the pulsed
MIG mode. The 0.045 (1.2mm) 300 series stainless weld wire was set at what should
have been an an optimum, conservative pulsed wire feed rate of 300
ipm. After welding each part, the parts were leak tested. The pulsed welds
looked good, yet the average weld
rework as revealed by the leak test was over ten
percent.
To fix the leaks, I first switched off
the pulsed mode and within a few minutes established new "spray transfer"
weld parameters. With the spray mode I set the 0.045 wire feed rate higher, at
"400 ipm". With the higher spray wire feed
rate I increased the actual weld production by 25%.
The leak test for the new spray transfer welds was "zero
percent".
THIS WAS A GREAT APPLICATION TO COMPARE THE MILLER PULSED MODE
WITH SPRAY TRANSFER. To reevaluate the pulsed mode at the same wire
feed rate set with the the spray weld, I then reset the Miller Invision power
source back to the pulsed mode and set the pulsed wire feed rate at 400
ipm. I then fine tuned the pulsed parameters to minimize spatter with the
shortest arc length. The new pulsed welds looked as good as the spray welds, however
WITH THE PULSED MODE IT'S OFTEN WHAT YOU DON'T SEE WITH THE WELD THAT SHOULD BE
A CONCERN.
With
the Miller pulsed equipment and the 0.045 wire set at 400 ipm, the pulsed
welds looked good on the couplings, however when the parts were leak tested
approx. 8% required weld rework. I
turned the pulsed mode off and from 2005 and these important auto / truck
part welds are made the old fashioned way, using "spray transfer".
For
those of you struggling with consistent pulsed MIG quality welds in the auto /
truck industry, be aware that in most instances the traditional spray transfer
arc on parts > 3 mm can provide superior weld fusion and be more stable.
As
much as weld equipment companies benefit from making their weld equipement complex
and costly, please note MIG welding has never been or needs to be rocket science.
The wires in that $10 toaster provide the correct amount of resistance and current
to maintain the wire in a consistent 
red heat condition.
As the photo on the right indicates,
for a few hundred dollars, you can put two car batteries
together, hook up a small spool wire feeder gun and produce an excellent
MIG weld.
In the simple task of melting the tip of a small diameter,
MIG weld wire, weld equipment manufactures today don't blink as they offer a sophisticated,
electronic pulsed MIG power source at the cost of a small car.
Pulsed
2008. It's the same stainless coupling company I visited
in 2004, only this time we compare the Miller Axcess pulsed mode against lower
cost CV equipment and the traditional spray transfer
mode.
In 2004 when an auto parts supplier had problem with the Miller Invision pulsed
MIG flange welds on the stainless couplings, I found that we could get the consistent
weld results the company desires by switching the pulsed mode off and welding
the the flange stainless welds with spray transfer. (See above story).
In
2008 Miller delivered it's new Axcess with a promise that the pulsed mode was
now stable and we would get excellent, spatter free welds results on the automated
stainless coupling welds. The coupling company had to purchase new MIG equipment,
so four years after the first Miller equipment trials they invited me back to
compare the Miller Axcess pulsed mode against the traditional spray mode I previously
recommended.
The automated weld cells had a two torch setup. One gun used
the Miller Invision set in the traditional spray mode. The other gun was connected
to a new Miller Axcess utilizing the Accu pulse mode. I ran both systems using
the shielding gas I developed,
Argon - 5 CO2 with an 0.045 (1.2mm) stainless
weld wire. The wire feed range tested was 300 to 500 ipm.
In the weld tests the Miller Axcess performed well in the pulsed mode. With both
the pulsed arc and spray arc lengths finely tuned to
minimize spatter, the results were again interesting. The Axcess package is priced
about 50% more than the Miller Delta Weld package. (DeltaWeld a traditional CV
power source). The Axcess pulsed mode did no better than the spray mode. It's
true that the average weld current from the pulsed mode was less, however lower
current on this application subject to leak tests was not a benefit. As for weld
spatter, the coupling weld position and small ID create an excellent weld spatter
trap, so weld spatter was a major concern. Again the Axcess did well on the spatter
count, however the spatter results between the pulsed mode and spray mode were
so minuscule that when the pulsed and spray parts were placed side to side, no
one could tell which was the spray weld and which was the pulsed weld. The Miller
Axcess did however provide weld benefits on another tube application in which
the the spray current limited the wire feed rate. When the pulsed mode was used.
it allowed for a higher wire feed setting. Typically the applications that will
benefit from pulsed are spray applications used are on parts < 3 mm or on parts
where you are using an 0.045 wire set between 250 and 320 ipm.
THE
SPRAY TRANSFER WELD PROOF IS IN THE RESULTS: I fine tuned the spray mode
and the afternoon shift ran 800 parts that required no cleaning or weld rework..
2008:
Pulsed and Conclusion on the Coupling: When automated weld cycle times
are less than 15 seconds, you will often find that a reduction in the weld cycle
time has limited impact as the manual operators that feed the parts cannot keep
up with the welding cycle.. In the case of this type of application, the benefits
of the higher cost pulsed equipment are still not clear. A company that makes
parts similar to this has three choices.
[1] They can invest $9000 dollars
for the pulsed power source and wire feeder.
[2] They can invest $90 for my
MIG Process Control training book and $475 for my Robot and Automated MIG Process
Control Training resource, along with
$5500 for a traditional CV power source and feeder, and save three thousand dollars.
[3] They can take a selective approach and only place the pulsed equipement
where it produces real world benefits.
WHAT
WELD BENEFITS ARE DERIVED, FROM
MAKING
THE MIG WELD EQUIPMENT
COMPLEX.
WHAT
THE PULSED MIG EQUIPMENT HAS TO DO TO MAKE THAT COMMON 1/4 (6 mm) FILLET WELD:
As the
pulsed MIG weld wire travels into the weld at typical speeds of 100 to 700 ipm,
that highly sensitive, artificial intelligent pulsed MIG power source has to;
[a]
Control and diagnose both the pulsed arc start and arc end
weld parameters. If the preset pulsed data does not
do the job will your weld personnel know how to set the correct data?
[b] Control and diagnose the pulsed low back ground current.
Does your weld decision maker know what the optimum pulsed back ground current
should be, or what an adjustment to the back ground current will do to the arc
or weld?
[c] Control and diagnose the pulsed
high peak weld current. Does
your weld decision maker know what the optimum pulsed peak would be, or what an
adjustment to the peak current will do to the arc or welds?
[d] Control and diagnose the pulsed frequency.
Does your weld decision
maker know what the optimum pulsed frequency should be, or what an adjustment
to the pulsed frequency will do to the welds?
[e] Control
and diagnose the pulsed pulsed
up-slope / down slope and the pulsed profile.
Does
your weld decision maker know what an adjustment to the pulsed profile, (select
one of 4 million available wave forms) will do to the welds?
[f] Control and diagnose
the pulsed arc length (trim) variations.
[h] Send a signal to a palm pilot or a computer.
FOR
DECADES SPRAY TRANSFER HAS BEEN A SIMPLE PROCESS, YET A
PROCESS FEW WELD SHOPS UNDERSTOOD.
IN
CONTRAST TO THE COMPLEXITIES ASSOCIATED WITH PULSED MIG, LOOK HOW SIMPLE IT IS
TO MAKE THAT COMMON STEEL FILLET WELD, USING A CV POWER SOURCE, AN ARGON CO2 MIX
AND 0.045 (1.2 mm) WIRE:
[1]
You select one of four optimum wire feed positions,
(from my books).
[2] You set the
optimum spray weld voltage
(from my books) and then
fine tune the voltage by the crackle sound or spatter length and shape to set
the correct arc length.
If
the weld shop was confused
about the two control spray,
what
hope does the shop
have understanding pulse?
A
traditional CV, MIG power source may be short on electronics, however it does
a great job while welding as it automatically
maintains the arc length during wire stick out variations.
The
low cost, durable MIG equipment provides two unique MIG
weld transfer modes suited to all metals. Short circuit provides controlled
low heat input suited from 20 gage to 0.100, while the higher energy spray mode
in many instances is superior to pulsed.
Did you know a regular CV power source is superior to an Inverter, a multi-process
or pulsed power source when used for welding gas shielded
flux cored wires?. (This info and evidence in my MIG and flux cored Process
Control training CDs).
There is
a great value in combining process expertise with a $2000 CV power source that
can handle the vast majority of the world's welding applications, however keep
in mind, this power source will provide less value to those that make and sell
the equipment.
PULSED,
SHORT CIRCUIT OR SPRAY TRANSFER DECISIONS AND WELD OPTIMIZATION ?
COMMUNITY COLLEGES DON'T DO IT, UNIVERSITIES DON'T  DO
IT AND THE MAJORITY OF THE WORLD'S WELD TRAINING PROGRAMS DON'T DO IT.
DO
YOU PROVIDE YOUR EMPLOYEES WITH MIG AND FLUX CORED WELD PROCESS CONTROL TRAINING.
IF THE WELD PROCESS CONTROL
TRAINING IS PROVIDED FROM MY CD, MIG AND FCAW POWER POINT PROGRAMS, THE WELD RESULTS
FOR YOUR ORGANIZATION CAN BE REMARKABLE.
[a]
WELD PERSONNEL WILL NO LONGER "PLAY AROUND"
WITH WELD CONTROLS ATTAIN OPTIMUM WELD DATA.
[b]
WELD PERSONNEL WILL KNOW WHEN TO SWITCH FROM SHORT CIRC, SPRAY OR PULSED
OR WHEN TO CHANGE THAT WELD WIRE SIZE FOR OPTIMUM WELD QUALITY
AND PRODUCTIVITY.
[c] WELD PERSONNEL
WILL IMMEDIATELY UNDERSTAND THE ROOT CAUSES AND
HAVE THE WELD PROCESS RESOLUTIONS NECESSARY FOR THE
COMMON ALL WELD ISSUES.
[d] WELD PERSONNEL
WILL UNDERSTAND THE RELATIONSHIP BETWEEN WELD COSTS, WIRE FEED SETTINGS AND THE
WELD DEPOSITION RATES THEY DAILY ATTAIN.
Click
here for the process control training resources you
will
benefit from.
|
ARE
YOUR PEOPLE WELD
PROCESS QUALIFIED?
WHY NOT GIVE THEM
THIS FUNDAMENTAL
MIG WELD
PROCESS CONTROL TEST
HOW FAR IN THE WELDING INDUSTRY DID WE EVOLVE BETWEEN
1985 AND 2005? Both welds indicated in the graphs below
are set with optimum weld data. If you were looking for arc stability take your
choice. Compare the voltage (red)
and current (black) graph on right from a regular $2000 MIG power source built
in 1985, with the pulsed mode graph on the left from a $12.000 USA manufactured
pulsed power source built in 2005.
Even
lawyers can figure this weld graph out.
In
my last weld process control presentation during Nov 2007. I was discussing weld
equipment with a large group of ASTEC / Kolberg engineers. There was two lawyers
present, ready to give a talk on patents. I asked the lawyers which of these graphs
they would accept to attain consistent, optimum MIG weld quality. You know
they both picked the one on the right
A
PULSED PICTURE IS WORTH A THOUSAND WORDS AND
THESE PICTURES COULD SAVE YOUR
COMPANY
THOUSANDS OF DOLLARS
The next two pictures are are two 3/16 (4.8 mm) fillet welds I made during 2003
on 1/4 stainless steel. The welds are made with a Lincoln
300 Power MIG. The 300 power source is a single
phase, pulsed MIG unit that retailed at that time for approx. $3,700. This
pulsed MIG power source has pre-scheduled pulsed programs for specific wire types
and diameters.
This Lincoln pulsed MIG power source was purchased by
a company that welds both steel and stainless parts. Due to it's daily welding
issues, (most caused by lack of process expertise) this company believed it needed
a unique pulsed power source. The MIG wires used for the 3/16 fillet welds was
an 0.035, (1mm) - 308L and 309 wire.
With the Lincoln power source, I
set the 0.035 wire feed at 550 ipm, a setting that should have been an optimum
pulsed wire feed rate. The power source provided the pulsed parameters, I simply
had to set the trim, fine tune the weld voltage to attain the optimum pulsed arc
length. The manual welds were untouched after welding. Take note of the pulsed
weld appearance and also the heat affected zone in contrast to the spray photo.
E-mail.
KD - P&F.
12/07
Ed, how are you doing? You would
be interested to know that by the end of the year I will have close to 100 robots
welding with 0.035 wire using spray transfer with no pulsing. It took 10
years Ed, but we are finally using the recommendations you
made in the nineteen nineties. I now have the top guy in North America
convinced traditional spray it is the way to go with the MIG applications. In
regards to your MIG process control training, we now have two plants that should
be interested in using you. I sent a copy of your book to one of the managers
at one of those plants, are you still available?
Note from Ed: This
is a USA, Mid West tier one company that produces
parts for Honda and Toyota. The plant has hundreds of robots and Panasonic pulsed
MIG equipment. The Panasonic weld equipment and pulsed process was a requirement
of the Japanese parent company. For more than a decade, the Panasonic pulsed MIG
equipment generated numerous pulsed MIG weld issues that dramatically impacted
the daily robot weld quality and production. With all the problems, the engineers
in Japan were reluctant to hear that the the traditional, more durable, lower
cost, North American CV equipment would provide solutions to the majority of their
welding isssues. I guess even Japanese engineers with time (ten years) will figure
out the solution to simple welding problems.
$3700:
Lincoln 300.
Pulsed MIG "On".
Lincoln
300: With the pulsed
mode turned "off".
With
the pulsed mode switched off, the Lincoln 300 power source was set to spray transfer.
Again a 3/16 stainless spray transfer fillet weld was made. The same weld wire
and wire feed rate as the pulsed weld were used . As you can see when comparing
both welds even the HAZ is similar. My point is simple. Why pay extra for the
pulsed electronics when you don't need them? Why pay for something that will be
less durable and more costly to repair?
Check the weld similarity from the two weld transfer modes.
Both
welds were made at same wire feed. Both welds are nothing to write home about.
This weld would be dramatically improved using spray transfer from a regular >
250 CV power source or working with a superior pulsed power source. . The welds
are simply a reflection of the inferior slope and poor operating characteristics
of this mediocre, single phase pulsed power source. So we have another weld shop
that purchased a product that did not live up to the salesman promises.
Note:
These stainless results above are not a fault of the pulsed transfer, they are
a result of the utilization of inferior pulsed MIG equipment.
PULSED
OR SPRAY WELDS ?
SAD
LOOKING WELDS ARE ALWAYS
A REFLECTION OF INEXPERIENCED,
SAD WELD MANAGEMENT.
The following pictures are robot pulsed MIG welds made between 2003 and 2005 on
Ford truck frames. The sad looking welds were made with one of the most expensive,
American manufactured, pulsed power source available, the "Lincoln
Power Wave".
I have been in too many auto /
truck frame plants and from a weld perspective it was usually a gut wrenching,
frustrating experience. I often think the coating they put on the frames after
welding is not there to prevent rust, it's there to make
sure no one can see the welds. The pathetic truck welds shown below are
of course not the fault of the workers on the floor and not the fault of the welding
equipment.
2003
- 2004. Weld Equipment. Lincoln Pulsed Power Wave.
Purchased by managers and
engineers who lacked
the ability to take ownership of a welding process.
Robot
welds: Managed and programmed by engineers and
robot weld personnel who lacked
the ability to establish
Best Weld Practices and Weld Process Controls.
Purchase
the most expensive and most sophisticated electronic
MIG equipment available.
Make some bad choices on the weld wire size selected. Mix in inexperienced, hands
off weld management. Toss in some poorly trained engineers, supervisors and technicians
and you will have the right combination to produce welds that look like they fell
out of the rear end of a pigeon as it flew over the parts.
What a combination, America's most expensive pulsed power source
welding on America's most expensive truck. Here in the USA we can blame the loss
of many jobs on overseas, due to labor costs or
superior Japanese quality, which from a weld perspective is simply a myth.
If we face weld reality, we may want blame a good portion of those US job losses
on under qualified, manufacturing management who for decades
lacked the ability to own and control what they own.
If
you cannot use a CV power source in your robot cell, at least
be aware of
how to set that pulsed or invertor power source.
Visit Ed's Weld Process Control Training Resources.
THE FOLLOWING
IS A CASE OF WELD PRODUCT SALESMANSHIP AND MARKETING THAT FROM MY PERSPECTIVE
REACHED AN ALL TIME LOW.
I was amazed to read one advertisement in the Nov.
2003. Weld Journal, a magazine that often struggles to walk a line between it's
adverting revenue and maintaining weld technology credibility.
The advertisement
in the magazine was from National Standard, (NS) a major North American MIG wire
manufacturer. The NS advert made unique and highly, exaggerated claims for it's
new N-S Pulse PLUS Steel MIG Weld Wire.
National
Standard claimed. "That
with their unique MIG wire and the pulsed MIG process you will get less weld
spatter, less weld fumes and their MIG wire will reduce the need
for grinding. NS also claims that there pulsed wire is supposed to provide
a wider operating range than competitive MIG wires.
The
N-S Pulse Plus MIG Wire.
When an industry has to rely on salesmanship,
there will always
a supplier ready to deliver it.
I
guess that $12000 pulsed power source you just purchased from Lincoln that's loaded
down with sophisticated electronics that controls the pulsed weld transfer, will
now provide an enhanced pulsed transfer with something which I believe is
one step above chicken fence wire.
This
type of weld product advertising belongs on the very top of the the mountain of
the never ending Bovine Fecal matter that for decades has spewed from the marketing
department many global weld equipment and consumable manufacturers. This is the
type of weld BS data that adds to weld shop myths and weld shop confusion. This
is part of the the BS that has helped destroy the technical credibility of today's
welding industry.
SHAME
ON National Standard, a major North
American weld wire
manufacturer, for its gross product lies and complete lack of respect for the
intelligence of it's welding customers.
SHAME
ON a Welding Journal affiliated
with the
none profit American Weld Society. This journal only benefit it's "paid
subscribers" as long as the information and advertising it provides
is credible.
SHAME
ON the
welding industry that's been using the MIG process for more than five decades,
an industry which still has many gullible readers that actually believed the NS
claims and purchased the wire.
This
MIG weld wire fiasco, is yet another reason it's important that the global weld
industry needs to take ownership of it's processes and why weld
decision makers need to cut the umbilical cord that has been attached to weld
equipment and consumable manufacturers for more than fifty years.
Weld shops take note: In the electronic challenge
of creating a single weld droplet per pulse, the pulsed power source has to provide
"numerous electronic changes per-micro second" unfortunately most power
sources built between 1984 and 2004 were not up to this challenge.
ROBOTS
AND HIGH SPEED WELD CONCERNS:
The
pulsed, inconsistent, lower open arc energy attained from < 2005 pulsed equipment
was not the logical choice for many high weld speed robot applications, especially
when you consider the two prime weld quality issues on many robot welds on steel
or stainless parts > 4mm was.
[1]
marginal or lack of side wall weld fusion.
[2]
inconsistent or skipped welds caused by inconsistent transfer of the electrons
across the arc.
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Visit
all the Weld Programs at this site
Visit Ed's Weld Process Control Training Resources.
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E-
Mail Weld Question
Sent: Thursday, June 19, 2003.
Subject: GMAW-P Problems
Hello
Ed. We are trying to utilize
GMAW-P on an HY-80 steel pipe welds. I was pushing for gas shielded flux cored
wires, but our engineers will not allow flux cored wires for our procedures. The
engineers complain of poor mechanical properties from the flux cored wires on
the HY metal. We can't use spray as many of the welds are out of position. We
are having a difficult time passing UT with our Miller Invision pulsed power source.
The MIG pulsed parameters required provide a wide arc zone and long arc length,
this results in inconsistent weld fusion.
We are thinking about switching
to Lincoln Pulsed equipment, as they tell us with their equipment that we can
control the pulsed wave forms and get better results. The Miller Equipment does
not allow wave form manipulation from the interface, you have to run off the factory
resets. Do you have any suggestions on getting better results with our GMAW-P
equipment?
Ed's Reply: Forget
that nonsense about "pulling a magic wave form out of that red machine".
Your question brings to light some of the pulsed process issues I have been talking
about for more than a decade. Pulsed variable parameters and pulsed arc length
sensitivity combined with a lower energy, fluctuating pulsed MIG arc plasma will
have welding consequences especially to those who are concerned about the weld
fusion attained. Of course to attain more weld energy with pulse one can always
increase the pulse parameters. However there are limits and when those parameters
are outside the optimum pulsed parameter range, you will not likely be pleased
with the resulting welds.
Good luck with the Lincoln
Power Wave and it's numerous wave forms.
I think you will find
that wave form control which sounds great in the Lincoln marketing brochure is
going to have have little impact on your weld applications. You may want to read
one of my many experiences with the Lincoln
2008,
the pulsed MIG process has not been able to compete with the superior
weld quality, higher deposition rate, easier to weld, all position gas shielded
flux cored wires developed in the 1970s - 1980s. .
The flux cored wires are of course optimized when used on the weld equipment
they were designed for, low cost, durable, CV. MIG equipment developed in the
1960s.
WELD
PROCESS CHOICES ARE MADE MORE DIFFICULT WHEN WELDS SHOPS ARE IMMERSED IN WELD
PROCESS CONFUSION: 
who
selected the sales driven pulsed MIG equipment or unnecessary three part gas mixes,
were typically not qualified to make rational MIG weld process / equipment selection
decisions. 
When
welding managers and engineers recognize that weld process
knowledge is far more important than the purchase of costly, useless electronic
weld equipment with bells and whistles, this industry will take a giant
leap towards establishing Best Weld Practices and Weld Process Controls.
