Non-Destructive Testing Stress Relieving

The welding process heats large areas of base material around the weld. Due to the thermal gradients, this heat affected zone can have a large number of residual stresses. Untreated residual stresses can lead to stress corrosion cracking and HIC. Residual stresses are released by heating the material to a temperature prescribed by the material type and thickness. The material is then cooled over a long period to allow material properties to equalize which reduces the risk of cracking.