STUDY OF HEAT-INDUCED AND RESIDUAL STRESS PATTERNS IN STAINLESS STEEL PIPE WELDS

Abstract

In This study provides a comprehensive analysis of the impact of welding parameters, specifically welding speed and the number of passes, on the residual stress distribution in AISI 304 (Z7CN18-09) austenitic stainless-steel tubes. A three-dimensional finite element model (FEM) was developed in ABAQUS to simulate the circumferential welding process. The DFLUX and FILM subroutines were employed to represent the double-ellipsoid moving heat source and thermal boundary conditions, respectively. Model validation was achieved by comparing simulated weld bead profiles and thermal cycles with experimental data, yielding excellent agreement (deviation < 5%).

The coupled thermal-mechanical analysis enabled the evaluation of the spatiotemporal evolution of the temperature field at various welding speeds (80, 160, and 240 mm/min) and the distribution of axial and circumferential residual stresses across the tube thickness. The numerical results highlight the significant influence of welding parameters on the magnitude and distribution of residual stresses. Optimized welding speeds were shown to reduce maximum stress levels, while multi-pass welding improved stress homogenization.