Effect of heat treatment on microstructure and
high temperature tensile properties of
cast nickel-base superalloy with
high W,Mo and Nb cont ents
high temperature tensile properties of
cast nickel-base superalloy with
high W,Mo and Nb cont ents
(1.Institute of Metal Research,The Chinese Academy of Sciences,
Shenyang 110016,China;
2.Mechanical Engineering Department,Shandong Institute of Technology,
Zibo 255012,China)
Shenyang 110016,China;
2.Mechanical Engineering Department,Shandong Institute of Technology,
Zibo 255012,China)
Abstract: The microstructural features and high temperature tensile properties of M963 superalloy at as-cast, as-solutioned and as-aged conditions were investigated in detail. The results show that the solution treatment at 1220℃ for 4h,AC causes an increase in high temperature yield strength but a drastic drop in high temperature ductility due to the precipitation of both the secondary carbide M6C along grain boundaries and at the interdendritic regions and very fine γ′ particles in the dendrite cores. Aging treatment following the solution treatment can improve the high temperature tensile properties of M963 super alloy due to the coarsing of the γ′ precipitate. One stage aging at 850℃ for 16h following the solution treatment causes an increase in both strength and ductility of alloy M963, and two-stage aging of 1089℃/2h,AC plus 850℃/16h, AC following the solution treatment further increases the ductility of alloy M963 but slightly decreases its strength.
Key words: cast nickel base super alloy;mechanical properties; microstructure; heat treatment