Influence of cooling way on microstructure and stress rupture property of DZ951 nickel base alloy
(1.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China2.Department of Superalloys, Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110016, China)
Abstract: The influence of different cooling during heat treatment on microstructure and stress rupture property of DZ951 alloy was investigated by optical microscope, SEM and TEM. The results show that the shape of MC carbide changes from Chinese script in as-cast alloy to small block with different cooling ways. The size of γ′ phase decreases and the shape of γ′ phase changes from cuboid to sphere with the increase of cooling rate. The γ′ phase splits into eight small cuboids when the alloy is cooled by furnace cooling. The stress rupture life of the samples by air cooling is superior to that by other cooling way.
Key words: heat treatment； cooling； microstructure； stress rupture life