先进超超临界机组用Inconel 617与C-HRA-2合金高温低周疲劳性能试验研究  

Experimental Study on High-temperature Low Cycle Fatigue Performance of Inconel 617 and C-HRA-2 Alloys for Advanced Ultra-supercritical Units

作　　者：周港宝 卞双[1] 陈震宇 陈正宗[2] 包汉生[2] 张乃强[1] ZHOU Gangbao;BIAN Shuang;CHEN Zhenyu;CHEN Zhengzong;BAO Hansheng;ZHANG Naiqiang(Key Laboratory of Power Station Energy Transfer,Transformation and System,Ministry of Education,North China Electric Power University,Beijing 102206,China;Institute for Special Steels,Central Iron&Steel Research Institute,Beijing 100081,China)

机构地区：[1]华北电力大学电站能量传递转化与系统教育部重点实验室,北京102206 [2]钢铁研究总院特殊钢研究所,北京100081

出　　处：《动力工程学报》2022年第5期475-483,共9页Journal of Chinese Society of Power Engineering

基　　金：北京市科技计划资助项目(Z181100005218006)。

摘　　要：针对先进超超临界(A-USC)机组用进口和国产候选镍基合金Inconel 617和C-HRA-2,进行了700℃下应变幅为0.25%~0.75%的轴向应变控制低周疲劳(LCF)试验研究。通过循环应力响应、循环应力-应变特性、疲劳寿命预测及断口形貌分析,研究了2种合金的LCF性能。结果表明:材料的循环应力响应和疲劳寿命与应变幅有关;C-HRA-2合金的循环硬化程度明显高于Inconel 617合金,但循环硬化后2种合金的峰值应力幅相近;2种合金的稳定迟滞回线均表现出non-Masing行为;Manson-Coffin模型和能量法均能有效预测疲劳寿命;不同应变幅下2种合金的疲劳源均萌生于试样表面,Inconel 617合金的疲劳裂纹以穿晶方式扩展,而C-HRA-2合金以穿晶和沿晶混合的方式扩展。The axial strain controlled low cycle fatigue(LCF) tests of imported and domestic candidate Inconel 617 and C-HRA-2 nickel-based alloys used in advanced ultra-supercritical(A-USC) units at high temperature of 700 ℃ were carried out, in which the strain amplitudes were ranging from 0.25% to 0.75%. LCF properties of two alloys were studied by cyclic stress response, cyclic stress-strain characteristic, fatigue life prediction and fracture morphology analysis. Results show that the cyclic stress response and fatigue life are related to the strain amplitude, and the cyclic hardening degree of C-HRA-2 alloy is significantly higher than that of Inconel 617 alloy, but the peak stress of two alloys after cyclic hardening is similar. The hysteresis loops of two alloys exhibit non-Masing behavior. Using Manson-Coffin model and energy-based method can effectively predict the fatigue life, and the fatigue initiations of two alloys originate from the specimen surface under different strain amplitudes. The fatigue crack propagation of Inconel 617 alloy is transgranular, while that of C-HRA-2 alloy is transgranular and intergranular.

关 键 词：镍基合金 低周疲劳 non-Masing行为 塑性应变能 寿命预测 

分 类 号：TG115[金属学及工艺—物理冶金]