高温合金IN792组织与持久性能稳定性研究

研究了700和900℃时效高温合金IN792组织的演变规律和持久寿命的变化情况。700℃时,随着时效时间延长,γ′和碳化物的形貌、尺寸与分布没有发生变化;持久寿命保持稳定。900℃时,时间延长,γ′发生粗化,并形成条状;且在1007h之后,条状γ′的形态基本不变;但时效到2014h时析出少量的针状TCP相;与热处理状态相比(61h),时效500h时持久寿命下降到30h,降低50%左右;时效到1007h之后,直至2014h,持久寿命不再随时间延长而变化。

Stability of Microstructure and Stress-rupture Properties of IN792 Superalloy

The evolutions of microstructure and stress-rupture properties were investigated during aging at 700 and 900 ℃.With the increase of aging time at 700 ℃,the morphology,the size and the distribution of γ’ and carbides did not change,and the stress-rupture time was stable.During aging at 900 ℃,γ’ was coarsened to be worm-shaped.The worm-shaped microstructure was stable from 1007 h to 2014 h.The needle-like TCP phase was precipitated when the alloy was aged for 2014 h,but its content was very small.The stress-rupture time was only 30 h when the alloy was aged for 500 h.It was shortened by 50% in contrast to heat treated state.The stress-rupture time did not change from 1007 h to 2014 h.