摘要
对断裂失效的城轨机车螺旋弹簧采用扫描电镜、金相检验、强度和硬度测试等方法进行。结果表明:该弹簧的断裂方式为疲劳断裂,显微组织、晶粒度和非金属夹杂物水平均正常,造成其断裂失效的主要原因是弹簧表面脱碳缺陷深度过大(>0.2mm),从而降低表面强度。基体组织的洛氏硬度和强度检测结果表明,其硬度和强度偏低,导致弹簧疲劳寿命显著降低而出现断裂失效。
A fracture analysis of urban rail locomotive helical spring was carried out by scanning electron microscopy,metallographic examination, strength and hardness testing. The results indicate that the fracture mode is fatigue fracture.The microstructure, grain size and nonmetallic inclusion evaluation are normal. The main reason for fracture is larger decarburization defects depth（〉0.2mm） existing on the surface of spring, which debases the surface strength evidently.Besides, the Rockwell hardness and strength of the matrix show that the hardness and strength are little lower, which can cause the significant reduction in the fatigue life of the spring and morphology of the fracture failure.
出处
《热加工工艺》
CSCD
北大核心
2014年第18期215-217,共3页
Hot Working Technology
基金
贵阳市科技计划项目(筑科合同[2013101]1-3)
