The welding process when fabricating exhaust parts induces some residual tensile stresses in the joints.
These tensile stresses act to stretch or pull apart the material surface which might initiate a crack when there are enough load cycles.
To improve the life of these welded metal fabrications, the residual stress levels in the materials (this can be stainless steel, Inconel...) need to be modified.
This can be done using either a shot peening process or a heat treatment.
At GoodFabs we work closely together with different companies to make sure that these processes are coordinated at the right time to ensure all delivery deadlines are met.
Image courtesy of Tamworth Heat Treament