【摘要】 在566℃、0.2%恒定应变条件下对GH4145合金进行2000 h拉伸应力松弛试验。结果表明:该合金具有良好的抗应力松弛性能。应力松弛试验前,GH4145合金由等轴晶组成,且晶粒大小不均匀,存在着尺寸相差较大的大、小2种晶粒。应力松弛试验后,小尺寸晶粒明显长大,致使合金的平均晶粒尺寸显著增大。应力松弛试验过程中,GH4145合金中各种形态和尺寸的二次γ′相长大缓慢,立方形二次γ′相的体积分数稍有增大,同时析出了尺寸更加细小的球形三次γ′相,致使合金的硬度升高。更多还原

【Abstract】 Stress relaxation behavior of GH4145 alloy at 566 oC was investigated. The results show that the alloy has good resistance to stress relaxation. Before the stress relaxation test, the GH4145 alloy is composed of equiaxed grains in a wide size range. After the stress relaxation test, the small particles grow obviously and thus the average particle size increases. Although the average grain size of the alloy obviously increases, the coarsening rate of secondary γ′ phase is very slow. The hardness of the alloy is increased by the increase of the volume fraction of cuboidal secondary γ′ particles with larger size and the precipitation of spherical tertiary γ′ particles with smaller size.更多还原