What Does Stress-Relief Cracking Mean?
Stress relief cracking occurs when susceptible alloys are subjected to thermal stress after welding to reduce residual stresses and improve toughness.
Stress-relieving is the process generally specified after welding of most materials. Removing or reducing the residual stresses generated by welding is required for improving the dimensional stability of weldments. Stress-relieving occurs by diffusion of atoms within solid materials.
Stress-relief cracking occurs only in metals that can precipitation-harden during such elevated-temperature exposure. It usually occurs at stress raisers, is intergranular in nature, and is generally observed in the coarse-grained region of the weld heat-affected zone.
Stress-relief cracking is also known as post-weld heat treatment cracking.