Local Post Weld Heat Treatment in Industry

In the manufacture, field fabrication, and repair of piping, problems associated with welding are common issues in these fields. Weldability of steel refers to the maximum hardness of the heat affected zone and the cold cracking susceptibility of welds. It may be necessary to heat components in different states, before welding (bake-out or preheating) between passes (interpass heating) or after welding (post-heating or post-weld heat treatment [PWHT]). This article focuses on all these heating purposes, with the main focus on PWHT. Brief discussions of the purposes for bake-out, preheat/interpass heating, post-heating, and PWHT are provided. Therefore, most emphasizes is given to the local ۳۶۰-degree band heating. However, limited consideration of local spot heating is also provided. Because the hardness caused by welding can cause destructive effects such as cracking and creating residual stress in the material, this article, tried to consider the practical aspects of the standard in the industry.

Keywords:

Post-weld heat treatment , thermocouple , Annealing , hardness , Soak Band