摘要
在630℃下,对P92钢进行应力控制下的蠕变-疲劳交互作用实验,研究P92钢高温蠕变-疲劳交互作用下的裂纹扩展行为,并结合断口形貌分析蠕变-疲劳裂纹扩展的机理以及a-N曲线的转折点含义。结果表明:P92钢在蠕变-疲劳交互作用下的断裂属于蠕变韧性断裂,应该用(C_t)_(avg)作为裂纹扩展的断裂参量;P92钢在蠕变-疲劳交互条件下,试样的断口主要表现为蠕变孔洞以及微裂纹。此外,发现a-lg(N_i/N_f)曲线以及(da-dN)-N曲线中的拐点,分别对应蠕变-疲劳裂纹萌生区向扩展区转变周次以及扩展区向瞬断区转变的周次。
Creep-fatigue interaction tests of P92 steel at 630℃ under stress-controlled were carried out, and the crack propagation behaviour of P92 steel was studied. The fracture mechanism of crack growth under creep-fatigue interaction and the transition points in a-N curves were analyzed based on the fracture morphology. The results show that the fracture of P92 steel under creep-fatigue interaction is creep ductile fracture and the （Ct）avg parameter is employed to demonstrate the crack growth behaviour; in addition, the fracture morphology shows that the crack growth for P92 steel under creep-fatigue interaction is mainly caused by the nucleation and growth of the creep voids and micro-cracks. Furthermore, the transition point of a-lg（Ni/Nf） curve corresponds to the turning point of initial crack growth changed into steady crack growth while the transition point of （da/dN）-N curve exhibits the turning point of steady creep crack growth changed into the accelerated crack growth.
作者
荆洪阳
唐梦茹
赵雷
徐连勇
JING Hong-yang TANG Meng-ru ZHAO Lei XU Lian-yong(School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072, China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2017年第5期112-117,共6页
Journal of Materials Engineering
关键词
P92钢
蠕变-疲劳交互
裂纹扩展
断口分析
断裂参量
P92 steel creep-fatigue interaction crack growth fracture morphology fracture parameter
