Effect of Groove Designs on Residual Stress and Transverse Shrinkage in GMAW and PGMAW of A333 Seamless Steel Pipes

Abstract

The effectiveness of weld joints primarily depends on the fusion of base metal, minimum heat-affected zone (HAZ) and lesser residual stresses. The severity of thermomechanical effects e.g. weld shrinkages and residual stresses is significantly minimized by narrow gap welding technique over the traditional welding. This work describes the welding of A333 Grade 3 steel pipes by the application of GMAW and PGMAW techniques. The analysis is made to capture the effects of groove designs on residual stress and transverse shrinkage. The process parameters used for the analysis are voltage, current and welding speed. In this work, narrow groove design using PGMAW process is capable of reducing the number of passes and area of weld deposit by 35–40% by volume. In PGMAW, decrement in residual stresses is observed with a narrow groove compared to conventional V groove technique. The results are validated by metallurgical and mechanical investigation of welded joints. This work will help other researchers to understand the effect of narrow gap welding using an optimum number of passes for thick pipes.