Activated TIG Welding of AISI 321 Austenitic Stainless Steel for Predicting Parametric Influences on Weld Strength of Tensile Test—Experimental and Finite Element Method Approach

Abstract

Tungsten inert gas (TIG) welding is the most common manufacturing process used to join materials like stainless steel, titanium and aluminium alloys due to their high-quality and inexpensive welds. Furthermore, the difficulty in welding plates having a thickness of 4 mm or more is overcome by employing activated TIG (A-TIG) welding process which uses an activating flux for high depth of penetration in a single pass. Uni-axial tensile test is conducted to assess the tensile strength of the material by experimentation. In this study, a uni-axial tensile test of base metal (BM) and weld metal (WM) samples are simulated using ABAQUS to evaluate the accuracy of finite element (FE) simulation results with the experimental results for predicting the tensile strength. The results show that the stress–strain values predicted by the FE analysis agree with experimental results. Also, the fracture behaviour of experimentation and FE simulation is identical with ductile mode of fracture. The fracture location of the sample in FE analysis is found very similar to experimental fractured samples. The results of ferrite measurement indicate that concentration of delta-ferrite in the WM (5.9 FN) is higher than BM (1.2 FN) content and show better mechanical behaviour in the A-TIG weldments. Also, scanning electron microscope (SEM) shows that the failure of BM and WM resembled to ductile mode-type fracture.