Microstructure and mechanical properties of dissimilar joint of stainless steel pipes using rotary friction welding

Dissimilar welding joints of different grades of stainless-steel pipes using various welding processes and technologies have received special attention in the world of manufacturing in the last few years, due to the wide application of different grades of this material in different sectors, including refineries, chemical plants, heat exchangers, and power generation plants. The utilization of rotary friction welding has significantly increased, and more studies on it have been conducted to reduce the difficulties of joining similar and dissimilar materials in general and steel in specific, as it decreases the heat input and thermal cycle. This study investigated the effect of continuous drive rotary friction welding and process parameters on microstructure and mechanical properties of the dissimilar joint of austenitic and super duplex stainless steel. The result of the study shows a significant relation between the friction and forging parameters and the joint quality. The best result achieved in this study was when the process parameters were selected as 30MPa for friction pressure, 10 seconds for friction time, 20 MPa and 30 seconds for forging pressure and time, respectively, and the rotational speed of 1030 rpm. The result reveals that the effect of the process parameters that have the most effect on heat input is more significant. And heat input in this process is a key point in achieving a good or poor joint quality.