Studies On Physical Properties And Microstructures Of GH536 Superalloy Argon-(shielded)arc Welding Joint

The microstructures and properties of GH536 welding joint is analyized in this paper, which provided theoretical basis for GH536 superalloy used in aerospace industry.GH536 is one kind of Ni-based wrought superalloy, with chromium and molybdenum solid solution strengthening. It has good comprehensive performance, such as high anti-oxidation and corrosion resistance. GH536 has excellent machining properties and welding performance, especially used for combustion chamber components of aero-engine and other high-temperature parts.A argon-(shielded) arc welding techniques is used to weld superalloys GH536. The physical properties and microstructures of the welded joint of superalloys GH536 are studied by engineer test, room-temperature tensile test, high-temperature tensile test, high-temperature stressrupture test, bend test, microhardness and metallographic analysis in this paper. The results show that the tensile strength of the welded joint of GH536 superalloy is 806.7MPa and the yield strength is 440.2Mpa, which are almost the same to the base metal, while the percentage elongation and reduction of area of the welded joint is lower than the vale of base metal of GH536. The bend nature, the high-temperature property and high-temperature stressrupture property of joints are well. And the high-temperature tensile strength of the welded joint is almost the same to the vale of base metal. The high-temperature stressrupture strength of the rolled and unrolled joints is more than 50Mpa at 900℃lasting for 100 hours. The microhardness of the joints is between 150 and 270 . The microstructure of welded joint is epuiaxial tree-like austenite. The microstructure of welding heat-affected zone and base metal are austenite. The grain size of welding heat-affected zone grows seriously.The results provide theorical foundation for application and extension of the superalloy for aviation industry.