Is there some with experience from shot peening parts before welding?
We have some problem with cracks in our welding process, the crack start in the welding joint and propagates in to the sheet metal. We are thinking about doing some test on Shot peening the Sheet metals (.24 inch) before joning them with weld to prevent the crack from growing in to the sheet. (The part is going to be heattreated after the welding to relax the tensions from the welding process, so the finish part want have any benefits from shot peening) Is there someone that have any experience in this or in simular cases.

Hello,

I have never heard of such a process when you shot peen the parts before welding. In order to perform the right procedure, you should understand the problem. After welding, the joined material experience high tensile stresses near the weld at an area called Heat Affected Zone (HAZ). These stresses tend to open the cracks (if exist) / help initiate new cracks. And in order to prevent such an effect, one should shot peen after welding.
The shot peening not only will induce compressive residual stresses but will improve the surface quality after welding, which will affect the joint's fatigue life.

Good luck!