喷油泵柱塞套失效分析

Failure Analysis of Plunger Sleeve of a Fuel Injection Pump

某喷油泵GCr15钢柱塞套在使用中早期断裂。对断裂的柱塞套进行了断口分析、化学成分分析、硬度测试、金相检验和能谱分析,以查明其断裂的原因。结果表明:柱塞套中孔表面有氧化铝夹杂物,在高压油的作用下使柱塞套产生纵向裂纹,最终在柱塞套最薄处发生断裂。

Plunger sleeve of a fuel injection pump,made from GCr15 steel,broke early in service.Fracture testing,chemical composition analysis,hardness testing,metallographic examination,and energy spectrum analysis were performed for the the broken plunger sleeve,for the purpose of finding out the cause of its breaking.The results showed that the plunger sleeve displayed alumina inclusions on the middle hole surface,and it was the alumina inclusions that caused the plunger sleeve to originate longitudinal crack and finally to break in its thinnest place under the action of high-pressure oil.