The study of effectiveness of half bead technique as an alternative to post weld heat treatment in welded joint

Abstract

Post Weld Heat Treatment (PWHT) had been used after welding to reduce the residual stress hence improved the properties of weld metal. The purpose of this project is to investigate the mechanical properties of weld metal using Half Bead Technique welding compare with Post Weld Heat Treatment (PWHT). This technique was developed using the Manual Metal Arc Welding (MMA W) process and was essentially aimed at providing an alternative to the used of Post Weld Heat Treatment (PWHT). Low carbon steel (Marine Grade) had been used as a parent metal. Each specimen performed with three type of welding technique. The welding techniques that had been performed throughout this research are full bead without post weld heat treatment, full bead with post weld heat treatment and half bead technique. So, there are six specimen produced in this research. Each specimen had been performed hardness test and bending test to evaluate the mechanical properties and the length of heat affected zone had been measured also the angular distortion produced had been recorded by each sample. The result stated that half bead technique give better performance than full bead welding with post weld heat treatment.