Investigation on friction-stir welding of SS340 steel using a tungsten carbide based stirring tool

Abstract

The research focuses on examining the impact of utilizing a tungsten carbide tool on the friction-stir welding procedure used to join two stainless steel plates. This investigation examines the effects of traversal speed and rotation on microstructural alterations in a tungsten carbide tool, with a specific emphasis on weld resistance and creep strength. Stress analysis is used to understand fluctuations in stress levels during the welding process on a stainless-steel workpiece. The investigation aims to determine the impact of welding parameters, specifically welding speed, on the microstructure, hardness distribution, and tensile strength of welded joints. The effectiveness of the friction-stir welding is determined by the correlation between pin diameter and tool shoulder. A Numerical model and analysis of the experiments to understand tool behaviour, considering lateral bearing loads and viscous frictional torsion loads by using ANSYS. The finite element method is used to find stress distribution in stir welding, considering tool parameters. A tungsten carbide tool with a conical pin tool was used under constant conditions: a rotational speed of 325 r/min, a maximum axial load of 11.2 kN, and a welding speed of 10 mm/min. The results showed that the maximum equivalent stress reached 500 MPa when the tool had traversed a distance of 25 mm. These findings provide valuable insights into the stress dynamics of the tool under these specific operating conditions. Different tests are conducted with varying design parameters and pre-hole conditions to understand the stress distribution on the tungsten carbide tool.