An experimental and numerical study of forces and residual stresses in AISI 316L stainless steel joints due to conventional and pulse gas tungsten arc welding

¹ Visteon Electronics Bulgaria, 90 Tsarigradsko Shosse Blvd., Capital Fort Building, 1000 Sofia, Bulgaria
² Technical University – Sofia, Plovdiv Branch, “Mechanical Technologies” Department, 25 Tsanko Diustabanov St., 4000 Plovdiv, Bulgaria
³ Technical University – Sofia, “Strength of Materials” Department, 8 Kliment Ohridski Blvd., 1000 Sofia, Bulgaria

^* Corresponding author: i_muhtarov@tu-sofia.bg

Abstract

This paper aims to present the results of a numerical and experimental study of the temperature field, internal forces and the residual stresses in 2 mm thick autogenous welds of AISI 316L stainless steel produced by continuous and pulse current gas tungsten arc welding. A special experimental device was used to measure the temperature and the internal forces due to the welding. The welds were qualified for internal and external weld imperfections according to ISO 15614-1. FEM software ANSYS® Multyphysics™ was applied in order to solve the thermal and mechanical problems. Normal residual stresses were measured by the hole-drilling strain gauge method in the continuous current weld. The peak value of the longitudinal stress was 80 % of the base metal yield stress. The magnitude of the numerically obtained residual stress values was found to be 16 % to 19 % above the measured one in the longitudinal and transverse direction, respectively. The experimental device used in this study allowed for a real time measurement of forces far from the weld seam. On the basis of the correspondence between the calculated and measured forces the numerical results were verified. Therefore, this device might open up new possibilities for determining thermo-mechanical material data.