Effect of Friction Pressure on Mechanical Properties of Austenitic Stainless-Steel Pipe Using Rotary Friction Welding

Rotary friction welding (RFW) is one of the most effective and efficient methods of joining for welding similar and dissimilar materials in different industrial applications. In this study, the influence of friction pressure of Continuous Drive Rotary Friction Welding (CDRFW) was investigated for welding austenitic stainless-steel pipe (grade TP316L) at two different friction times, while other welding process parameters remained constant during the process. The results demonstrate a complex relationship between the friction welding parameters. For the first set of samples with a longer period of friction time of 45 seconds, increasing the friction pressure decreases the mechanical properties. In contrast, for a shorter period of friction time of 15 seconds, increasing the friction pressure increases the mechanical properties. The best result among the welded samples was achieved at the highest friction pressure and the shorter friction time, with the tensile strength reaching 457 MPa. However, for the longer period of friction time of 45 seconds, the tensile strength is dropped to a minimum of 171 MPa. The key parameter in this process is the heat input, which must be carefully controlled. Excessive or insufficient heat input can lead to improper bonding and poor weld quality. The findings of this study show that welded joints with the highest friction pressure combined with lower friction time give the best result of tensile strength and hardness profile. In contrast, the high friction pressure and friction time together need to be avoided to prevent degraded weld performance.