摘要
研究了４２ＣｒＭｏ钢亚温淬火及二次淬火两种双相组织的疲劳裂纹扩展行为，结果表明，亚温淬火双相组织可显著提高裂纹萌生抗力，降低扩展速率；较高的疲劳性能与裂纹尖端闭合应力、断口表面粗糙度以及裂纹扩展路径弯折程度有关。断裂力学分析表明，粗糙度诱发裂纹闭合效应及裂纹路径弯折效应是提高裂纹扩展抗力的主要因素，同时得到上述两种效应对裂纹扩展速率影响的表达式。
The fatigue crack propagation of dual-phase microstructures was investigated in 42CrMo steel. The results showed that the dual-phase structures could significantly increase the crack initiation and propagation time and decrease the propagation rate.The high fatigue properties were found to be related with higher crack closure stress,rough fracture surface and tortuousity of crack path. Based on the analysis of fatigue fracture mechanism,it was concluded that the superior fatigue crack growth resistance of the dualphase structure was attributed to the roughness-induced crack closure effect and deflection effect as well, which reduced the effective driving force at the crack tip.
出处
《材料科学与工艺》
CAS
CSCD
北大核心
1994年第3期40-45,共6页
Materials Science and Technology
关键词
双相组织
裂纹扩展
中碳合金钢
dual-phase structure
fatigue mechanism
crack propagation
closure effect
