Microstructure and Properties of Nickel-Based Superalloy C-276 Pulse Laser Weld Joints Based on 0.381mm Thickness

摘要

Based on Ilastelloy C-276 sheet materials, the microstructure, element segregation and mechanical properties of weld joints were studied using pulse laser welding technology. It is noted that there are three morphological grains in the weld zone, which is columnar dendrites, cellular crystals and equiaxed grains, respectively. Compared with the base metal, the microstructure of the weld zone is obviously refined. Element segregation exists in the weld zone where no secondary phases formed. In addition, the microhardness of the weld joints is greater than that of the base metal by 12%. Its yield strength is equivalent to the yield strength of the base metal, and the tensile strength is 93% of that of the base metal. There are plenty of dimples in the fracture of the weld joints and the base metal, and the fracture modes of both are all ductile fracture.