摘要
采用销加载拉伸(PLT)方法和直流电压降法(DCPD)测试技术,测量了690合金管在室温和高温325℃空气中的疲劳裂纹扩展速率。结果采用Priddle模型拟合分析,预测得到了690合金管在室温和325℃下的门槛应力强度因子幅值ΔK_(th)和断裂韧性K_c,高温下材料的疲劳裂纹扩展速率明显加快,表现为ΔK_(th)和K_c显著下降。试验结束后在扫描电镜下观察断口形貌,疲劳裂纹的扩展为穿晶形式,疲劳断口上观察到大量的TiN夹杂物,分析表明TiN夹杂物对690合金管的疲劳裂纹萌生和扩展有促进作用。
Fatigue crack growth rates（FCGR） of alloy 690 tubes were obtained in air at room temperature（RT） and 325 ℃ by pin-loading tension（PLT） and a direct current potential drop（DCPD） method. Testing data were fitted with Priddle model, and thus the threshold stress intensity factor amplitude ΔKth and fracture strength Kc were predicted. Results show that at higher temperature, fatigue crack growth rates are much faster than that at RT; as a result, the ΔKth and Kc decrease at higher temperature. Scanning electron microscopy（SEM） results reveal that the propagation of fatigue crack is transgranular attack, and the fracture surface is covered with a lot of TiN inclusions. It is reasonable to believe that TiN inclusions could enhance fatigue crack initiation and propagation of alloy 690 tubes.
作者
陈凯
杜东海
陆辉
张乐福
石秀强
徐雪莲
Chen Kai;Du Donghai;Lu Hui;Zhang Lefu;Shi Xiuqiang;Xu Xuelian(Shanghai Jiao Tong University, Shanghai 200240, China;Shanghai Key Laboratory for Nuclear Power Engineering, Shanghai 200233, China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2018年第4期1180-1184,共5页
Rare Metal Materials and Engineering
基金
大型先进压水堆核电站重大专项(2010ZX06004-018)
