20Cr钢单向器轴在试车时发生破裂, 通过化学成分分析、宏观和微观检验对破裂原因进行了分析。结果表明: 单向器轴的渗碳层深度过深, 马氏体和碳化物级别严重超标。碳势过高、热处理过热导致淬火时开裂是零件破裂失效的根本原因。

20Cr axes of unilateralism organ had broken during short time test, the cracking reason was analyzed by means of chemical composition analysis, macro and micro examination.The rerults showed that, carburized layer＇s depth was too much, the degree of reticulation carbide and martensite were exceed standard seriously. The overhigh carbon potential and overheating of heat treatment led to quenching cracking, wihch was the central reason for the cracking and failure of the unilateralism organ.