Welding Characteristics of Type XM-19 Stainless Steel

Type XM-19 stainless steel is a potential structural material for pressure vessel applications in small modular reactors (SMRs). In this study, the welding characteristics of XM-19 stainless steel were investigated using autogenous gas tungsten arc welding (GTAW) and fiber laser welding. The weld morphology, solidification behavior, and microstructure were evaluated using microscopy and solidification-mode prediction. Both GTAW and laser welds exhibited A-mode solidification under all investigated welding conditions; the dominant solidification morphology differed between the two welding processes. Additionally, Z-phase was observed in the interdendritic regions of both arc and laser welds.