Evaluation of the Microstructure and Mechanical Properties of Dissimilar Joint between Pure Copper and Stainless Steel 316

In this research, dissimilar joints between copper and stainless steel 316by gas-tungsten arc welding using copper and monel filler metals and also the similar welding of steel 316 have been investigated. The microstructure was studied by OM, SEM and EDS. Tensile and impact tests were done to evaluate the mechanical properties. In order to investigate the sigma phase formation, the specimens were heat treated. The microstructure of the dissimilar welds contained an iron rich and a copper or monel phase. After heat treatment, no sigma phase was observed in the dissimilar joint that it seems that the presence of copper and nickel as an austenite stabilizer elements in the microstructure prevents the sigma phase formation.