摘要
本文通过使用扫描电子显微镜等手段,探讨了不同浇注温度下K403返回料高温合金中晶粒组织、γ′相及断裂机制,研究了晶粒尺寸与γ′相对合金高温持久性能的影响。结果表明:在焙烧温度为1050℃,空冷和风冷条件下,随着浇注温度在1420℃~1490℃范围内的升高,合金的平均晶粒尺寸先降低后增大,γ′相尺寸逐渐增大,合金在975℃/195 MPa试验条件下的持久寿命出现先降低后增加的趋势。K403在975℃/195 MPa试验条件下的持久断裂机制为沿晶断裂,且γ′相均发生了与拉应力方向垂直的筏化现象。
In this study,scanning electron microscope(SEM)was used to investigate the grain size,γ′phase and the fracture mechanism of K403 alloy casted at different temperatures.The effect of grain size andγ′phase on the stress rupture property of alloy was studied.The results indicate that as pouring temperature increases from 1420?C to 1490?C,followed by calcination at 1050?C and cooling by air or wind,the average grain size of alloy decreases firstly and then increases,the size of theγ′phase gradually grow up,and the life of alloy at 975?C/195 MPa tends to decrease firstly and then increase.The fracture of K403 alloy during stress rupture tests is mainly characterized by intergranular fracture,meanwhile,γ′phase is rafted perpendicular to the direction of tensile stress.
出处
《冶金工程》
2019年第2期80-88,共9页
Metallurgical Engineering
