Welding Tips and Tricks

Hello!

I work as a fabricator at a sled testing facility. We do crash simulation of vehicle bodies. I’m currently building a test fixture that the B-Pillar and roof structure consists of Usibor 1500 which is a hot formed steel. I plan an reinforcing the vehicle body, attaching to the b-pillar and roof structure, with 2x2 mild steel box tubing and trying to figure out the best way to attach the dissimilar metals. I’ve welded some scrap pieces together, which it seems to weld okay, I’m just concerned with longevity, as this test fixture will be used multiple times. Through some research I’ve found that auto body repair uses silicon brazing on these types of materials. I’ve never used that process before, and was wondering if that would be a better option than just using regular filler wire and mig welding the mild steel to the hot formed steel. Any input would be appreciated!

Thanks!

Looking at the pubished data: https://automotive.arcelormittal.com/pr ... r_ductibor

There doesn't seem to be a big issue welding it as they state: " MAG, MIG and conventional metal welding techniques, including brazing, can readily be applied."

And of course like most car body parts these are resistance spot-welded into structures at assembly time anyway. It's basically still steel, just alloyed.. (oh and coated with Zinc or Alu of course..).

Also 'ArcelorMittal can provide technical support for welding parameter adjustment.'. You could shoot them a message to see what hey say. But from your description I suspect there's no big issue welding to this. The only thing I can imagine is that the HAZ around the weld becomes annealed so it's less strong than the rest.

As far as I know the difficulty for actual repairs in shops on parts like this comes from actually trying to fix-up such structures instead of cutting out damaged ones and welding in new replacement pieces as sections. A repair on a large part of such a panel/rib/structure will likely weaken it a lot and brazing may be a 'workaround' to stop it annealing and losing it's strength.

Bye, Arno.

That's what I figured, just wanted to get another opinion or to see if anyone had personal experience. I believe I actually read through that article once before. I'll go ahead and weld to it. The rest of the structure is pretty rigid, and the welds are only to help support the roof structure.

Thanks for the reply! It's much appreciated!