Post weld heat treatment is a controlled process which consists in heat the welded joint without reach the critical temperature of transformation (AC1). The post weld heat treatment is often usually after the union by welding of two material base such us carbon steels or alloy steels.

Post weld heat treatment (PWHT) can be apply to one complete piece or locally, by applying only the heat treatment to the welded joint area.

The post weld heat treatment (PWHT) will help to:

• remove the hydrogen that could be retained in the base material after welding
• reduce tensions created in the HAZ (Heat-affected zone)
• reduce and control hardness

As a consequence, it will be reduced the possibility of appearance of cracks. The cracks could contribute to have problems of corrosion.