is a method for reducing and redistributing the residual stresses or stress in the material that have been introduced by welding. The extent of relaxation of the residual stresses depends on the material type and composition, the temperature of PWHT and the soaking time at that temperature.

Beneficial Effects

  • Improve toughness of certain steels; especially steels with relatively high carbon.
  • Mitigate SCC (Stress Corrosion Cracking) in some Service.
  • Outgas hydrogen. (Need can be mitigated by strict low hydrogen practices).
  • Reduce residual stresses; important in SCC service and for dimensional control after machining.

Induction - Post Weld Heat Treatment