长期时效对GH761合金组织与性能的影响

Effect of Long-Term Aging on Microstructure and Properties of GH761 Alloy

研究了真空感应+真空自耗双真空冶炼工艺条件下GH761合金在650℃和700℃长期时效后的组织和性能变化。结果表明,合金在650℃长期时效后,γ′相尺寸没有明显变化,数量有所增加,拉伸强度随之提高;700℃时效时,γ′相尺寸随时效时间增加而增大,但对室温和650℃拉伸强度影响不大。650℃/637MPa条件下的持久寿命在经650℃和700℃时效2000小时后有所增加;合金经650℃和700℃长期时效后没有新相析出,组织和性能稳定。

The effects of long time aging at 650 ℃ and 700 ℃ on the microstructure and properties of GH761 alloy produced by vacuum induction melting(VIM) plus vacuum are remelting(VAR) techniques were studied. The results showed that after long term aging at 650 ℃, the size of γ′ phase was unaffected, but the amount of γ′ phase was increased and the tensile strength was found to be enhanced. At 700 ℃, with the aging time prolonged, the γ′ phase was coarsened slightly, but the tensile properties at room temperature and 650 ℃ were hardly affected. It also showed that the stress-rupture life of the alloy at 650 ℃/637 MPa was increased with the aging time prolonged at 650 ℃ and 700 ℃. There was no new phase precipitated after long-term aging at 650 ℃ and 700 ℃, which indicated that the microstructure and properties stability of the alloy was good.