Post Weld Heat Treatment (PWHT) reheats the welded material using a controlled ramp-soak profile with a temperature below its initial transformation temperature. The temperature ranges from 595˚C to 775˚C depending upon the properties of the metal/material. The heating rate is determined and controlled by the type of material thickness. The holding temperature is the one that is high enough to relieve stress and reduce hardness, but it is lower than the initial transformation temperature. Uneven or quick heating or cooling can form cracks in the component. Heating and cooling rate, holding temperature, and soak duration must be controlled and monitored precisely to avoid any detrimental effects such as reheat cracking, distortion, decrease in the toughness, and over softening to obtain the full benefit of the process.