低铬合金钢的超高周疲劳行为和裂纹扩展路径分析  

VHCF Behavior and Crack Path Analysis for Low Chromium Alloy Steel

作　　者：黄志勇 王清远[1] 

机构地区：[1]四川大学建筑与环境学院,四川成都610065

出　　处：《四川大学学报（工程科学版）》2012年第5期195-199,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(5110117)

摘　　要：SAE5120钢是汽车行业中齿轮构件使用的材料,其实际使用循环数超过了109。研究经过热处理、普通渗碳或表面低压渗碳处理后的低铬合金钢的超高周疲劳行为,应用压电超声疲劳试验机(20 kHz,应力比R=0.1)完成超高周疲劳试验,并获得处理后材料的超高周疲劳行为。通过对表面渗碳处理后试件断口的裂纹扩展路径分析,研究材料表面渗碳处理、微观结构、与杂质有关的裂纹萌生及断裂机理,根据高倍扫描电镜的裂纹条纹测量和应力强度因子计算对Paris公式的参数进行了估计。SAE5120 is a mobile gear component material in the automobile industry of USA,and its service cycles are beyond 109.A piezoelectric gigacycle fatigue machine is employed to do fatigue tests in VHCF regime in the condition of 20 kHz frequency,stress ratio R=0.1,and room temperature.The effects of heat and carburizing and low pressure carburizing treatment to VHCF fatigue strength were investigated.Moreover,the scanning electron microscopy（SEM） observation of fracture surface was analyzed to investigate the mechanism of fracture related to surface treatments,microstructure and inclusion.The long crack propagation behaviour was described by the Paris equation and parameters of the model were evaluated by the crack striation spacing of the high magnification SEM photos.

关 键 词：超高周疲劳 高强度钢 低压渗碳 微观结构 

分 类 号：O346.1[理学—固体力学]