高温合金IN792组织与持久性能稳定性研究

Stability of Microstructure and Stress-rupture Properties of IN792 Superalloy

摘要:

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1007 h之后，条状γ′的形态基本不变；但时效到2014 h时析出少量的针状TCP相；与热处理状态相比 (61 h)，时效500 h时持久寿命下降到30 h，降低50%左右；时效到1007 h之后，直至2014 h，持久寿命不再随时间延长而变化

Abstract:

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