Microstructure and mechanical properties of the 316 stainless steel nuclear grade experimental component made by wire and arc additive manufacturing

An experimental component of nuclear grade austenitic stainless steel 316 (SS316) shielding plate was manufactured by wire and arc additive manufacturing (WAAM) method. Its microstructure, tensile properties at room and high temperatures, Vickers hardness, and impact properties were analyzed. The results show that the microstructure of WAAM SS316 product is mainly composed of austenite (gamma) and delta-ferrite (delta) phases. The delta exhibits a fine vermicular morphology in the austenite matrix and is distributed at the boundaries of and inside the grains. The tensile properties of WAAM SS316 product are comparable to those of wrought SS316 and exceed the corresponding requirements of the nuclear industry. WAAM SS316 product has good uniform impact toughness in all directions, and the impact energy can fully meet the technical requirements of the nuclear industry with excellent performance. The results of nondestructive testing show that the quality of the WAAM SS316 shield plate product meets the evaluation requirements of the nuclear industry.