HXD_(1)型电力机车电机吊杆裂纹成因分析

Cause Analysis and Research on Cracks of HXD_(1) Electric Locomotive Motor Suspender

分析电机吊杆裂纹产生原因,对保障机车运行的可靠性、提高机车的使用寿命有重要意义。对HXD_(1)型电力机车电机吊杆裂纹进行了宏观形貌和微观组织观察,并检测了电机吊杆的化学成分、机械性能和硬度。结果表明:电机吊杆表面多数裂纹尖端呈钝化特征,裂纹性质应为制造过程中产生的沿晶热裂纹。非金属夹杂物沿晶界分布,使得该缺陷区域的晶界成为薄弱环节,铸件在随后的热处理加工应力作用下沿晶界开裂并扩展,个别裂纹延伸至内壁边缘,可能导致电机吊杆早期失效,应予以重视。

It is of great significance to analyze the cause of motor suspender cracks to ensure the reliability of locomotive operation and improve the service life of locomotive.The macroscopic morphology and microstructure of cracks in motor suspender of HXD_(1) electric locomotive were observed,and the chemical composition,mechanical properties and hardness of motor suspender were inspected.The results show that most crack tips on the surface of the motor suspender show passivation characteristics,and the cracks property could be intergranular thermal cracks produced in the manufacturing process.The distribution of low melting point non-metallic inclusions along the grain boundary makes the grain boundary in the defect area a weak link.The casting cracks and expands along the grain boundary under the action of subsequent heat treatment processing stress,and individual cracks extend to the edge of the inner wall,which may lead to the early failure of the motor suspender,which should be paid attention to.