Recrystallization Annealing Temperature

When welding cold-formed material, you have to be careful: The forming process leaves stresses frozen in the structure. The welding heat can release them, but only if the right temperature is reached – otherwise the stresses stay in and the part cracks or warps.

The temperature depends on the material; for steel it's in the range of the annealing temperature. It's important that the zone around the weld stays hot long enough for the structure to transform. So put in enough heat and don't let the part cool too quickly, then it'll be fine.