Microstructure and mechanical properties of GH3230 superalloy laser welding with filler wire

GH3230 superalloy has broad application prospects in the aviation field. The process, microstructure, and mechanical properties of laser welding with filler wire were investigated, and the weld formation, joint microstructure, room temperature tensile properties, and high-temperature endurance performance were compared with those of traditional tungsten inert gas welding (TIG) joints. The results have shown that the GH3230 butt joint with good shape can be obtained by the laser welding process with filler wire. The formation quality is better than TIG joints. As the energy density of the laser becomes larger, the heat-affected zone (HAZ) of joints is smaller. In terms of microstructure, the large temperature gradient and short duration of the molten pool lead to a weld microstructure mainly composed of dendrite crystals. The precipitation carbides that distribute between and within the grains contribute to precipitation strengthening. In terms of mechanical properties, the room temperature tensile specimens of joints by laser welding with filler wire fracture at base metal (BM), while TIG joints experience a decrease in room temperature tensile properties due to grain coarsening and reduction of carbides, resulting in fracture at the weld seam. Under high-temperature conditions, the high-temperature endurance performance of TIG joints is slightly higher than that of laser welding with filler wire, and both are higher than that of the BM. In the bending test, both joints by laser welding with filler wire and TIG joints show no crack defects and exhibit reliable bending performance.