One of the fastest growing technologies in metal-working today is the application of tailor weldedblanks for the manufacture of automobiles andtrucks. According to experts in the business, such

as Matt Takahashi, deputy general manager of technolo-gy, at ProCoil, Canton, MI, the correct terminology eitheris tailored blanks or tailor welded blanks.

Exponential GrowthTom Fant, president, TWB (Tailor Welded Blanks)

LLC, Monroe, MI, points out, The industry is growingrapidly as the quality of the welding and throughput ofthe process continue to increase. TWB, like several oth-ers in the industry, makes its own laser welding equip-ment. Notes executive vice president, Manfred Nagle,The learning curve the industry was on several yearsago required us to learn how to design the proper dies

to handle materialof different thick-nesses welded intoone part. That learn-ing curve has beenpassed, and the in-dustry is expectedto grow rapidly forseveral years.

In te res t ing lyenough, Nagleadds, the Euro-peans started withsmaller piecesrails and so on. TheAmerican automo-bile industry beganwith larger partslike doors and sidepanels. Today eachis moving towardthe other direction.

The growth po-tential is exponential, adds Iban Melter, vice president sales, TWM. The real growth is in the acceptance of thetechnologyworldwide acceptance. Were looking atthe entire body-in-white now.

Looking at the 2000 model cars, continues TWB

president Tom Fant, they average 1.6 tailor weldedblank parts per car. There are some 23 parts to the bodythat are appropriate for this technology. About 17 mil-lion vehicles will be produced. That provides some ideaof the potential.

Some 25 to 26 million tailor welded blanks for carsand trucks will be produced by the industry for NorthAmerican automotive companies in 2000. TWB will turnout some 8 million of those parts at its Monroe, MI, plant.Like most companies in the business, TWB is a partner-ship between steel companiesin their case, Thyssen,Worthington Industries, LTV, Bethlehem and Rouge.

So what are tailored blanks and tailor welded blanks?Basically, ProCoils Mr. Takahashi explains, weretalking about welding together steel blanks of varyingthicknesses and different coatings as well. He uses a carpart as an example. Where do you need more material

for strength, for ex-ample, in a car door?Where the hinges aregoing to go. So welaser weld severalblanks together ofdifferent thicknessesand have a doorblank that will havethicker material inthe hinge areas.

All the advantagesof this are not imme-diately obvious. It isnot just weight sav-ings that is makingthis process so at-tractive to car andtruck producers. Upto 14 different opera-tions can be avoidedin making car doorswith tailor welded

blanks, for example. Theres no need for reinforcementsin the hinge areas, and you dont need special brackets.In effect, the use of tailor welded blanks simplifies someof the parts making.

ProCoil, Canton, MI, (owned by National Steel), uses

Where DoesULSAB Go Now?

T he Ultra Light Steel Auto Body(ULSAB) project was an attemptto promote the use of steel incars. The final design of this all-steel,body-in-white used some hydroform-ing, both tubular and sheet, somesteel sandwich technology and tai-lor welded blank technology. ULSABwas financed and directed by a con-sortium including nearly all steel mak-ers, worldwide, all auto companiesand was led in the U.S. by Porsche En-gineering and the American Iron &Steel Institute AISI) in Southfield, MI.The project was officially finished in1999. However, as sources at AISI ex-plain, there is more to do about steeland cars and a whole new emphasishas been developed for the still-intactconsortium.

Jack M. Noel, director, auto/steelpartnership and Marcel van Schaik,manager, advanced materials technol-ogy, automotive applications commit-tee, AISI, point out that the ULSABproject is finished, but now we areworking on ULSAB-AVC. AVC is forAdvanced Vehicle Concepts.

The two researchers note that theyare concentrating on intangible ben-efits in terms of cars. In other words,theyre looking at the total vehicle nowinstead of just the body structure.Some 90 percent of the original mem-bers are remaining in the consortiumalong with some new members, suchas South Africa and China.

The new effort will be in looking atmaterials that exist now only in labs,but will be available for productionuses in cars by 2004. ULSAB-AVCalso now is affiliated with the FederalGovernments Partnership for a NewGeneration of Vehicles, which has agoal of 80-mpg technology.

By George Weimer, Contributing Editor

Tailor Welded BlanksTrans forming VehicleProduction and Assembly

butt-welding in its process-es. However, the car com-panies are using differentlaser techniques and willbe doing more and morewelding for curvilinear ap-plications. There already isone part, a floor pan, thatwill be welded in a nonlin-ear way by laser.

Nearly all the laser weld-ing equipment used in theprocess comes fromSoudronic AG, Neftenbach,Switzerland. We have justinstalled a new Soudronic,and we have ordered a sec-

ond one, points outPatrick W, Hartigan, Pro-Coil sales manager. Wedont plan on stopping at two welders, he adds.

Whats special about theSoudronic technology is itsspeed and accuracy interms of laser welding. Thecompany notes that a typi-cal automotive front railuses nine stampings and isassembled with approxi-mately 120 spot welds.Using their laser welderand tailored blanks, the op-eration is reduced to threesub-blanks with two weldsprior to stamping.

The issues of straight-ness and rigidity are para-mount in laser welding tai-lored blanks, Soudronicnotes. Their machines aredesigned for and usually dowork around the clock. Ofspecial significance, theyadd, is the very tolerantbutt welding process re-garding edge quality andstraightness due to the ma-chine integrated online edge preparation with theirmismatch prevention devices.

Tailored blanks are butt welded on this new line at ProCoil, Canton, MI.

Pat Hartigan, ProCoil sales manager,points out that they have just installed anew Soudronic and have ordered a sec-ond one. We dont plan on stopping attwo welders, he adds.

Equipment at Olympic Laser Processing,Van Buren Township, MI, uses equipmentthat can handle both linear and nonlin-ear work.

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Tailor Welded Blanks

These technolo-gies are called Souma(Soudronic mashwelding) and Soulas(Soudronic laserwelding) and aredesigned so thatidentical or at leastsimilar modules canbe used. Neverthe-less, the system maychangedependingupon the application.

The basic sys-tems include manu-ally loaded and unloaded semi-au-tomatic weld sys-tems. They can beupgraded as re-quired with mod-ules into fully auto-matic weld systems.Automation mod-ules include loadingstations with robotsto destack theblanks from the pal-let cart and feedthem into the welder,Soudronic explains.

After welding, seamtreatment modulessuch as cleaningand oiling units canbe integrated. Dim-pling units and turn-ing units are forproper stacking ofthe welded blanks. Further stacking stations with robotsand pallet carts are for stacking of the finished blanks.

Auto manufacturers usually provide custom-designedpallets and pallet handling equipment for companies inthe business of providing tailor welded blanks, accord-ing to general manager, Mark Williamson at OlympicLaser Processing.

Other equipment manufacturers include AutomatedWelding Systems, Markham, Ontario, as well as TWB,Power Laser, Noble, Prototech, Shiloh and JBI.

The techniques involved have been understood for20 years. Soudronic sold its first system to Volvo in 1979.However, it has been only in recent years that theprocess basically has been adopted on a wholesale basisby the auto industry at large. Growth rates of 40 percent,in terms of the size of the tailor welded blank fabricationindustry, mean that more of the welding systems will begoing on-stream in the next few years.

A final report will be finished on thetotal vehicle in mid-2001.

As for tailor welded blanks, the re-searchers expect the trend to contin-ue, with some 30 million such partsused in 2000and upwardsof 70 millionparts expectedin 2005. Theprocess is usedmuch more inEurope, sincethey use tailorwelded blanksin places wherecrash perfor-mance is criti-cally important.

Trends intailor weldedblank fabrica-tion technologyinclude moreand more non-linear welding,more interest in YAG lasers, far greaterefficiencies in the manufacturing ofsuch parts, elimination of precisionshearing and the use of die cut edges,more and more custom steel pallets,and cleaner material handling.

Were starting a program calledSAFE, they add, which stands forsafety, affordability, fuel efficiencyand environmentally friendly. The ideais to see to it that steel stays on theagenda of car makers and tailor weldedblanks are part of that. We will be aim-ing for their use in crash performanceareas as they already are in Europe.ULSAB-AVC prepares an annual reporton its research as well as a tailor weld-ed blank manual that is available onthe Internet at www.a-sp.org.

ULSAB-AVC also now is affiliated withthe Federal GovernmentsPartnership fora New Genera-tion of Vehicles,which has agoal of 80-mpgtechnology.

Nearly all of the laser welding equipment usedin the process comes from Soudronic AG,Neftenbach, Switzerland. Photo courtesy of ProCoil, Canton, MI.

After welding, seam treatment modules, such ascleaning and oiling units, can be integratedinto the system. Stacking stations with robotsand pallet carts are for stacking of finishedblanks. Photo courtesy of ProCoil, Canton, MI.

24 www.metalforming.com MetalForming/February 2000

Tailor Welded Blanks

Already, the number of suchcompanies has grown to nearly 20.Many of these are companiesformed by steel makers and largeservice centers as well as the autoproducers themselves. Clearly, it isthe policy of the auto industry tomove to tailored blanks as fast aspossible and in as many appropriateareas as practical.

One area of focus for the industryis to use tailor welded blanks inareas of critical crash performance.They are used in Europe for suchapplications. However, Americanauto companies so far have avoidedsuch uses. (See USLAB box). Manyof the companies in the business arecentered within 50 miles of Detroit.

Suffice it to say that the use of tai-lor welded blanks in all but the exte-rior parts of a car will continue tospread rapidly throughout the vehi-cle. And, if a weld can ever be madeso smooth and even as to be com-pletely unnoticeable to the touch,then even exterior parts may use theprocess. MF

The Roller Seam Weld Methods

Flow Chart for Typical Tailored Blank Welding System

Illustrations on this page furnished by Soudronic AG,Neftenbach, Switzerland.

26 www.metalforming.com MetalForming/February 2000