40Cr钢锥阀断裂失效分析

采用低倍金相、扫描和透射电子显微镜，对40Cr钢锥阀断裂的原因做了分析。结果表明，造成该阀断裂的原因是由于锥头氮化层破裂，脱落形成网状小裂纹。裂纹萌生源头含有露头冶金缺陷，非金属夹杂物和沿晶析出富铬脆化相，致命与金属基体结合能力降低而发生脆断。

The fracture failure analysis or 40Cr steel cone valve

This paper makes an analysis for the reason of fracture of 40Cr steel cone valve by the use of low - powered, metallographical scanning, transmission electron microscope. The result shows that the reason is that the nitration case at cone tip ruptures and pulls out into net crack, and that the crack eruption origin has outcrop metallurgical defect, non - metal impuritier and high - chromium brittle phase educed along grain bomdary which makes metal's biding ability decrease and brittle fracture occur.