GH783合金热稳定性研究

Thermal Stability Study on GH783 Alloy

研究了抗氧化低膨胀GH783合金环件在700℃长期时效后的组织和性能的变化。结果表明,合金在700℃长期时效100 h^1 000 h后,强化相γ'有粗化的趋势,但比较缓慢;β相补充析出,数量增加不明显;室温和高温拉伸强度稍有降低;光滑和缺口持久寿命在时效100 h后有所降低,随时效时间的延长,缺口持久寿命有提高的趋势,不存在缺口敏感性。GH783合金环件在700℃长期时效中组织和性能是稳定的。

The microstructure and mechanical properties of low thermal expansion and oxidation-resistance GH738 alloy ring after long time aging at 700 ℃ was investigated in this paper. The results indicated that the main strengthening phase γ′ is coarsening slowly, β phase supplementary precipitates with no obvious increment in its quantity and tensile strength at room temperature and high temperature deceases slightly during aging at 700 ℃ for 100 h^1 000 h. Stress rupture life of both smooth samples and notched samples decreases after aging at 700 ℃ for 100 h. The stress rupture life of notched samples increases with the increasing of aging time, but notch sensitivity would not occur. GH738 alloy ring has good structure and mechanical properties stability during long time aging at 700 ℃.