GM GMT900 Case Studies

SUV Rad Support made out of

aluminum converted to

Pick-Up Rad support out of steel

Presented By: Bo Lindgren

VP Engineering

Pick-Up Steel

Radiator Support

• GM steel Rad-Support

production started in

2006

• Volume 600,000 to

1,000,000 /year

Product – Aluminum

Radiator Support

• Our initial order from

GM was an aluminum

rad support structure,

used in their full size

SUV vehicles

• Redesigned from aluminum to

steel

• Mass neutral (compared to

aluminum)

• High strength steel profiles

• Variable thickness material

• Higher load requirement

• Why? Cost savings

Challenge – Pick-Up

Steel Radiator Support

Laser-welded steel profiles

Inner and outer post

Upper and lower tie-bar

Lower Tie Bar •Hot dip galvanized

•Variable thickness

material 1.9 to

1.0mm

•Dual phase

material

550 mpa

•1640mm long

Variable Thickness Material

1.9 mm 1.0mm 1.9 mm

All features are done before welding

Embossing Extrusion

Lower Tie-Bar weld seam

Early Options

Use a flange to create a

lap-weld

Final T joint

•Hot dip galvanized

•16 micron coating

•Laser beam from the

side

•Out-gassing from the

backside

Upper Tie Bar •Galvanized

•Thickness

1.0mm

•Material HSLA

420 Mpa

•Profile formed

after welding

Upper Tie-Bar

• Material galvanized HSLA 420 material

with thickness of 1.0mm

GMT 900 STEEL RAD SUPPORT

MANUFACTURING EQUIPMENT

Early Options

Design of the part profile

Weld

Change

this area.

Early Options

Early Options

Weld area

Early Options

Lap joint

Final configuration for upper tie bar

Upper Tie bar

Laser cutting after welding and forming

Late design change

end tab feature

Upper tie-bar problems showing up

Material changing from uncoated to

galvanized

Inner post

•Uncoated material

•Material 1.0mm

thick

•HSLA material

420 Mpa

The profile started

out with a

overlap in this area

for welding

Inner post

Inner post

Final product

Butt Welding of inner and outer post

Outer Post

•Uncoated material

•Material 1.1 mm

thick

•HSLA material 420

Mpa

•Part manufactured

as a 2-up and

formed before

splitting

Outer Post

Part

manufactured as

a 2-up and

formed before

splitting

Thank you for your interest

Presented By: Bo Lindgren

VP Engineering

w w w . a u t o s t e e l . o r g

North American

Light Vehicle Metallic Material Trends

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