50CrVA碟形弹簧开裂原因分析

Analysis on Cracking Cause of 50CrVA Disc Spring

某平台压载系统使用的50CrVA碟形弹簧在服役过程中开裂。为查明原因,对开裂及未开裂的碟形弹簧分别进行宏观检验、化学成分分析、显微组织检验、力学性能检测和断口形貌观察。结果表明,开裂及未开裂碟形弹簧的化学成分、表面质量和力学性能均符合标准要求,显微组织均为回火屈氏体;开裂碟形弹簧内锥面与内圆面交界处存在部分脱碳层,未开裂碟形弹簧无脱碳现象;开裂碟形弹簧断口表面具有典型疲劳开裂特征。

The 50CrVA disc spring used in a platform ballast system cracked during service.In order to find out the reason,the macroscopic inspection,chemical composition analysis,microstructure inspection,mechanical property inspection and fracture morphology observation were conducted on cracked and uncracked disc spring,respectively.The results showed that the chemical composition,surface quality and mechanical properties of cracked and uncracked disc springs met the standard requirements,the microstructure was tempered troostite.There was a partial decarburization layer at the junction between the inner conical surface and the inner circular surface of cracked disc springs,and no decarburization phenomenon was found in the uncracked disc springs.The fracture surface of cracked disc spring had typical fatigue fracture characteristics.