Numerical Investigation of Residual Stresses and Distortions due to Multi-Pass Welding in a Pipe-Flange Joint

Abstract

This paper presents a numerical simulation for examining temperature fields, residual stresses, and distortions in multi-pass welding of a pipe-flange joint. A sequentially coupled transient non-linear thermo-mechanical three-dimensional finite-element model is developed to simulate four-pass tungsten inert gas welding process. An ANSI class 300{#} flange is welded with a 6 mm thick, 200 mm long, and 100 mm nominal diameter pipe, using a single V-groove butt joint with a 1.2 mm root opening. Goldak's double ellipsoidal model is used for the weld heat source, and inactive element addition technique is used for the addition of weld filler elements. Axial and hoop residual stresses and out-of-plane distortions along the flange face are plotted. In addition, welding start and end effects are discussed.