气动凿岩机活塞失效的分析与研究

Analysis and research on failure of piston of pneumatic rock drill

使用光学显微镜、电子显微镜对气动凿岩机活塞失效试样进行分析。发现凿岩机活塞外表面组织为回火马氏体和少量的残余奥氏体,芯部组织为回火索氏体,内表面组织为板条马氏体和大量的残余奥氏体。冲击韧性试验表明,活塞内表面处试样冲击韧性平均值为46 J/cm^2,与材料30CrNi4Mo冲击韧性值范围110～184 J/cm^2相差很大,此为活塞失效的主要原因。

The failed specimen of the piston of the pneumatic rock drill was analyzed with OM and SEM.Observations showed: the microstructure of the outer surface of the piston of the pneumatic rock drill involved tempered martensite and a small amount of residual austenite, the core involved tempered sorbite, the microstructure of the inner surface involved lath martensite and a large amount of residual austenite. The impact toughness test showed the average impact toughness of the piston sample on its inner surface was 46 J/cm^2, which was very different from that of 30CrNi4Mo ranged 110 ~ 184 J/cm^2. It was the main cause of piston failure.