Abstract: In order to satisfy simultaneously the mechanical and welding properties of the aerospace-used forged GH4169 alloy parts in solution treated state, the effect of solution treatment temperature on hardness and tensile properties of the alloy forging was studied, and the qualities of homogeneous welding and dissimilar metal welding for solution treated GH4169 alloy and 0Cr18Ni9 stainless steel were characterized at corresponding solution treatment temperatures. The results show that the solution treatment temperature has significant impact on microstructure and mechanical properties of the GH4169 alloy, the dissolved degree of coarse second phases (δ phase mainly) increases and both the hardness and the tensile strength reduce significantly with the increase of solution treatment temperature, while the elongation increases significantly. The experiment results of both the homogeneous welding between GH4169 alloy solution treated at different temperatures and the dissimilar metal welding with the stainless steel 0Cr18Ni9 indicate that their macrostructure, microstructure and X-ray test results all satisfy the requirement for using. Considering both the mechanical properties and welding properties, the optimal range of solution treatment temperature of the GH4169 alloy forging used in solution treated state is 900-940 ℃.

Key words: GH4169 alloy, forging, solution treatment temperature, mechanical properties, welding quality