Distortion on Stainless Steel

Date 03-28-2008 08:34

Stainless sheet stock can be a pain....

Some things you can do is use "chill bars", "heat sinks", (whatever you want to call them)....basically we are talking about a copper or aluminum backing to your weldment that is much thicker then what your welding. This helps soak up some of the heat and reduce distortion. Basically clamp your "sinks" to your metal with as much solid surface contact as you can get. Any kind of fillets or butt welds are going to result in a lot of drawing....fitting your butt welds with a set gap and lots of tacks prior to welding helps a lot. Remember on SS you will be putting in way more tacks much closer together then what you might on carbon. Clamping a solid piece of flat stock on both sides close to your weld will also help things stay straighter. Just remember you need to restrain that metal close to the weld with something much more rigid and anything you can use to absorb the heat will help as well.

Another usefull technique is backstepping your welds.....10 inch long weld, (example)direction of travel will be left to right, so weld the last 2-3 inches on the right side, then go 3 inches to the left of where you started that weld and weld left to right till you get to your last weld and repeat. This can be a great way to keep from putting to much draw in a joint.

Hope that helps out
Tommy

By jrw159

Date 03-28-2008 14:27

Good reply Tommy. SS is a real beast when it comes to distortion and weld draw.

By 100perpen (*)

Date 03-28-2008 16:45

The Avesta Welding Manual has some tips as well. We have referred to it here and it has helped with reducing the shrinking on SST. frames.

By Stringer (***)

Date 04-03-2008 03:05

If it's a cosmetic weld where the metallurgy isn't critical, you can also include wet rags to your tricks. Lay short beads, skip around, take breaks and do something else. The distortion is caused by heat shrinkage, so if you limit distance the heat travels into the sheet you can limit the shrinkage. I've also used silicone heat dam gels. I hate them. All of these methods are messy, and multiple starts and stops mean the final finish will be accomplished by grinding, sanding and buffing. To me this is too much like automotive body work so I have to really like the project to do this sort of work.