某型号车轮螺栓拉长和断裂原因  

Reasons for bolt elongation and fracture of a wheel

作　　者：武坤 杨帆 王秀健 李皓 郑喜平 WU Kun;YANG Fan;WANG Xiujian;LI Hao;ZHENG Xiping(Zhengzhou Jingyida Auto Parts Co.,Ltd.,Zhengzhou 450000,China)

机构地区：[1]郑州精益达汽车零部件有限公司,郑州450000

出　　处：《理化检验（物理分册）》2022年第11期65-68,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某型号车轮螺栓在装配过程中出现拉长和断裂情况。采用宏观观察、化学成分分析、力学性能测试、硬度测试、金相检验、扫描电镜及能谱分析、摩擦性能测试等方法,分析了螺栓拉长和断裂的原因。结果表明:螺栓和螺母的扭矩系数一致性较差,在装配过程中,夹紧力超过螺栓屈服强度,导致螺栓拉长;当扭矩系数过小时,夹紧力超过螺栓的抗拉强度,导致螺栓断裂。The wheel bolts of a certain model were elongated and fractured during assembly. The causes of bolt elongation and fracture were analyzed by means of macroscopic observation, chemical composition analysis, mechanical property test, hardness test, metallographic examination, scanning electron microscope and energy spectrum analysis, friction performance test. The results show that the torque coefficients of bolts and nuts were not consistent. During the assembly process, the clamping force exceeded the yield strength of bolts, resulting in bolt elongation. When the torque coefficient was too small, the clamping force exceeded the tensile strength of the bolt, resulting in the bolt fracture.

关 键 词：车轮螺栓 塑性变形 拉长 断裂 扭矩系数 

分 类 号：TB31[一般工业技术—材料科学与工程] TH131[机械工程—机械制造及自动化]