Indentation Behavior of Additively Manufactured 316L Stainless Steel Welded Joints via Gas Tungsten Arc Welding and Laser Welding

Additively manufactured 316L stainless steel specimens were welded by two different techniques: gas tungsten arc welding (GTAW) and laser welding (LW). The relationship between indentation hardness (H IT ) property and microstructure evolution of the different weldments were studied. Microstructural analysis of the weldments was conducted using laser confocal scanning microscope, while hardness measurements were obtained through micro-indentation Berkovich approach. The microstructure of FZ in GTAW joints displayed austenite matrix with ~2 wt.% delta ferrite, whereas its counterparts welded by LW displayed a fully austenitic structure. This is attributed to the various applied heat inputs, 360 and 50 J/mm for GTAW and LW, respectively. Despite, a filler metal of ER-316L was used in GTAW, LW was autogenous, i.e., without a filler metal. Consequently, the H IT of the FZ processed by GTAW was lower than that processed by LW, recording 1.98±0.18 GPa and 2.1±0.14 GPa, respectively.