Post weld heat treatment (PWHT) is a controlled process in which a material that has been welded is reheated to a temperature below its lower critical transformation temperature, and then it is held at that temperature for a specified amount of time.

Include:

1. Heating the welding part with heating rate
The rate of heating when PWHT is performed is typically based on the component's thickness and is specified by the governing codes.

2. Hold at the temperature for some time
Holding temperature and time are governed by the material and thickness respectively.

3. Cooling
As with the heating rate, the cooling rate must be controlled also.

Post weld heating treatment type:

1. Resistance heating Ceramic heating pad
2. PWHT furnace
3. Induction PWHT