40Cr钢副轴断裂分析  

Analysis of 40Cr Steel Countershaft Breaking

作　　者：贺凯林 宋锐 杜兴 HE Kailin;SONG Rui;DU Xing(Muyang Holdings Co,Lud,Yangzhou 225127,Jiangsu China;Famsun Co,Ltd,Yangzhou 225127,Jiangsu China)

机构地区：[1]江苏牧羊控股有限公司,江苏扬州225127 [2]江苏丰尚智能科技有限公司,江苏扬州225127

出　　处：《热处理》2020年第6期51-53,56,共4页Heat Treatment

摘　　要：40Cr钢副轴仅仅使用了1个月即发生断裂。对断裂的副轴进行了断口分析、化学成分分析、金相检验和表面硬度测定。结果表明:副轴的化学成分和表面硬度符合要求,断裂部位表面粗糙,且存在可能是副轴与其他部件之间的摩擦热导致的二次淬火层。应力集中和二次淬硬层使副轴的疲劳缺口因子增大,导致疲劳裂纹萌生和扩展,使副轴过早断裂。40Cr steel countershaft broke when used for as little as one month.The broken countershaft was tested for fracture pattern,chemical composition,microstructure and surface hardness.The results showed that the countershaft had chemical composition and surface hardness which conformed with requirements,but offered relatively rough surface and secondary hardening layer which stemmed perhaps from friction heat between it and other components.The stress concentration and the secondary hardening layer rendered fatigue notch factor of the countershaft greater,and,as a result,fatigue crack initiated and propagated in it,resulting in its premature breaking.

关 键 词：疲劳断裂 二次淬火层 摩擦热 黏着磨损 

分 类 号：TG142.1[一般工业技术—材料科学与工程]