关键词: GH3536合金, 选区激光熔化, 固溶处理, 显微组织, 力学性能

Abstract: Effect of different heat treatment processes on the microstructure and mechanical properties of selected lasive melting GH3536 alloy was studied by means of OM, SEM, and mechanical properties tests. The results show that, with the solution treatment temperature increasing, the grain size increases, the tensile strength increases gradually at high temperature and decreases at room temperature. When the solution temperature reaches 1120 ℃, the tensile strengths of transverse and longitudinal specimens at room temperature can reach 816 and 731 MPa, respectively. While that of transverse and longitudinal test bars reach 189 and 204 MPa at 900 ℃, respectively. After aging at 800 ℃, the alloy matrix can precipitate fine carbides, which has an effect on second phase strengthening, and so that the strength can increase. With the increase of aging time, the carbides become denser, but the grain size changes a little, which leads to the increase of both tensile strength and percentage elongation after fracture at room temperature. When the aging time reaches 20 h, tensile strengths of the transversal and longitudinal test bars at room temperature reach 832 and 747 MPa, respectively. The percentage elongations after fracture of transversal and longitudinal test bars at 900 ℃ reaches 8.5% and 21.5%, respectively. Finally, the optimal heat treatment process for the selective laser melting GH3536 alloy is solution treated at 1120 ℃ for 1 h, and then aged at 800 ℃ for 20 h.

Key words: GH3536 superalloy, selective laser melting, solution treatment, microstructure, mechanical properties