Effect of Post Weld Heat Treatment (PWHT) on Mechanical Properties, Chemical Composition, and Microstructure on Carbon Steel Pipe SA-106 B with SMAW-GTAW Welding Combination

chemical composition:, mechanical properties:, microstructure:, PWHT

Abstract

Welding is one of the company's success factors in connecting high-pressure pipes to welding technology implementation projects. The PLTU (Power Plant) construction project carries out the welding process in every construction activity that involves welding experts and various other disciplines. This research uses an experimental method with PWHT temperature variable on mechanical characteristics, microstructure, and chemical composition. The material used is SA-106 B carbon steel pipe with a 6G welding position. Welding is carried out using a combination of SMAW welding with E9016-G electrodes, and GTAW welding with ER90S electrodes. The higher the PWHT temperature, the tensile strength, hardness, and chemical composition of the carbon content and microstructure of the pearlite phase (dark etching) will decrease. Meanwhile, the impact energy will increase and the ferrite phase will experience growth in the ferrite grain structure (bright etching).