6106型柴油机排气阀失效分析  

Failure Analysis of 6106-type Diesel Exhausted Valves

作　　者：程世长[1] 李文成[1] 刘正东[1] 林肇杰[1] 

机构地区：[1]钢铁研究总院,北京100081

出　　处：《失效分析与预防》2006年第3期33-37,共5页Failure Analysis and Prevention

摘　　要：6106型柴油机在载重车上运行4万公里和8万公里后发生排气阀"掉头"和"掉块"事故,本文对失效排气阀的金相组织和断口进行了观察分析,分析结果表明,金相组织正常,可以排除冶金质量和热处理的问题,发生在颈部的"掉头"事故,是由于机加工精度不高,表面存在"沟槽"引起。发生在盘部的"掉块"事故,是由于21-4N钢高温强度不足引起的。＂ Head-off＂ and ＂piece-off＂ accidents occurred when 6106-type diesels of trucks served at 40000km and 80000km respectively. The microstructure and morphology of fracture surface of failed exhausted valves were investigated. It was found that the microstructure is normal, implying that metallurgical processes and heat treatment may not contribute to the failure of the valves. Meanwhile, ＂ head-off＂ of the valves is basically resulting from the fact that non-enough machining accuracy, as some grooves existed in the surface of the valves. ＂Piece-off＂ failure is due to the non-enough elevated temperature strength of 21-4N steel.

关 键 词：柴油机 排气阀 沟槽 裂纹 

分 类 号：TK42[动力工程及工程热物理—动力机械及工程]