Optimization of process parameters of rotary friction welding of low alloy steel tubes using response surface methodology

Rotary Friction Welding (RFW) is a solid-state welding process that is becoming increasingly popular due to advantages such as low weld heat input, high production efficiency, ease of manufacture, and environmental friendliness. Rotary friction welding can weld materials that are difficult to fuse using fusion welding techniques. The main objective of this study is to join SA 213 T12 and SA 213 F12 low alloy steel (LAS) tubes using a rotary friction welding process and to optimise welding parameters such as friction pressure, forging pressure, and rotating speed. To optimise the welding conditions, the response surface method (RSM) was applied. Empirical relationships were developed to predict tensile properties such as tensile strength (TS), yield strength (YS), elongation (EL), notch tensile strength (NTS), and notch strength ratio (NSR). Using the test results, the tensile properties of the rotary friction-welded low alloy steel (LAS) tubes were determined. The optimum process parameters for better tensile properties of the rotary friction welded joint are found to be rotation speed (N) 60 rps, friction pressure (FF) 0.851 MPa/s, and forging pressure (FOF) 0.851 MPa/s.