城轨机车螺旋弹簧断裂分析  

Fatigue Fracture Analysis on Urban Rail Locomotive Helical Spring

作　　者：徐军[1,2] 梁益龙[1,2] 易艳良 严振[1,2] 

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550025 [2]贵州省材料结构与强度重点实验室,贵州贵阳550025

出　　处：《热加工工艺》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)

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.

关 键 词：51CrV4螺旋弹簧 疲劳断裂失效 表面脱碳 

分 类 号：TG162.74[金属学及工艺—热处理]