低合金钢在不同条件下的疲劳行为  

THE FATIGUE BEHAVIOR OF LOW ALLOY STEEL UNDER DIFFERENT CONDITIONS

作　　者：刘彦国[1,2] 马进[3] 孙先明[2] 

机构地区：[1]浙江机电职业技术学院,杭州310053 [2]武汉材料保护研究所,武汉430030 [3]浙江农林大学工程学院,临安311300

出　　处：《力学与实践》2010年第6期49-53,59,共6页Mechanics in Engineering

基　　金：国家自然科学基金重点项目(50432020);浙江省自然科学基金项目(Y107428)资助

摘　　要：在空气和腐蚀介质中对低合金钢分别进行疲劳试验,获得了S-N曲线,并对疲劳试样表面和断口形貌进行了观察.结果表明:与空气相比,腐蚀介质使低合金钢的疲劳强度显著降低;在空气中疲劳试样只有一个萌生于试样表面基体的裂纹源,而腐蚀介质中一般有多个裂纹源,多数裂纹源均萌生于点蚀坑;空气中疲劳裂纹扩展区以疲劳辉纹为主,而腐蚀疲劳则以沿晶开裂等脆性特征为主;此外还对空气中的疲劳极限进行了预测,预测值与试验值比较吻合.The fatigue behavior of low alloy steel in air and corrosion media was studied by fatigue tests. The S-N curves were obtained and the observations of specimen surfaces and fatigue fractographs were made. The results show that the fatigue strength of low alloy steel in corrosion media is much lower than that in air. Fatigue cracks in air are initiated from the matrix of surface,while most of fatigue cracks in corrosion media are initiated from pits.The fatigue crack propagation region in air features typically with fatigue striations,while that in corrosion media has intergranular crack characteristics.The fatigue limit in air could be predicted by an empirical equation,and results agree well with the experimental fatigue limit.

关 键 词：低合金钢 疲劳行为 裂纹萌生 疲劳极限预测 

分 类 号：TG405[金属学及工艺—焊接]