【摘要】 研究了不同热处理工艺对M963合金显微组织和拉伸性能的影响。结果表明,经1 210℃,4h空冷固溶处理后,合金的强度升高,但塑性降低,尤其是在高温(900℃)时塑性降低幅度更大;固溶处理后再进行850℃,16h炉冷时效,强度进一步提高,高温塑性获得恢复,但室温塑性进一步降低。扫描电镜观察发现:合金在1 210℃,4h空冷固溶处理过程中,初生MC碳化物发生转变,并在晶界和枝晶间析出M6C碳化物; 在固溶处理后的空冷过程中,从g固溶体基体中析出细小g相;经850℃,16h低温时效后,g充分析出并长大。断口形貌分析表明不同热处理状态的合金,其断裂机制不同。根据位错与强化相之间的相互作用理论讨论了这种热处理工艺对室温和高温拉伸性能的不同影响规律。更多还原

【Abstract】 The effects of heat treatment on the microstructural and tensile properties of conventionally cast M963 superalloy both at ambient temperature and 900℃ have been investigated. The results show that the solution treatment at 1 210℃ for 4h followed by air cooling causes an increase in the tensile strength but a decrease in ductility especially at high temperatures; After the solution treatment, aging at 850℃ for 16h followed by furnace cooling further increases the tensile strength and the ductility at high temperature but decreases the ambient temperature ductility. Scanning electron microscope (SEM) observation reveals that the primary MC carbide becomes different and secondary M6C carbide precipitates at grain boundaries and interdendritic regions during the solution treatment at 1 210℃ for 4h. Fine g phase particles precipitate from the g solid solution during air-cooling following the solution treatment. The aging treatment at 850℃ for 16h makes a fine g phase precipitate and grow. Analysis of the fracture surface indicates that the fracture mechanism varies with heat treatment condition. The effects of heat treatment on the tensile properties at both ambient and high temperatures is discussed in terms of interaction between dislocations and particles.更多还原