R18CrNi8喷油嘴针阀体断裂原因分析  

Analysis on broken of needle valve body of R18CrNi8 steel

作　　者：郑卫 黄瑞 ZHENG Wei;HUANG Rui(Baosteel Special Metals Long Product Co. ,Ltd. , Shanghai 200940, China;Baoshan Iron & Steel Co. ,Ltd. , Shanghai 201999, China)

机构地区：[1]宝钢特钢长材有限公司,上海200940 [2]宝山钢铁股份有限公司,上海201999

出　　处：《宝钢技术》2022年第2期51-55,共5页Baosteel Technology

摘　　要：柴油发动机的“心脏”即燃油喷射系统的喷油嘴是关键的部件。某公司针阀体在装机过程中发生针阀卡死、针阀体开裂现象,断裂针阀体材料为R18CrNi8钢。失效零件通过化学成分、夹杂物、宏观体式、微观金相、扫描电镜检测分析,结果显示:零件化学成分、夹杂物、带状组织符合标准要求,零件的开裂原因为球头座面内壁渗层碳化物分布不均,在针阀与针阀体座面碰撞时造成应力集中,从而产生纵向开裂。The“heart”of the diesel engine,namely the nozzle of the fuel injection system,is the key component.The needle valve body of a company has been stuck and cracked in the process of installing the machine.The cracked needle valve body is made of R18CrNi8 steel.The components were tested by chemical composition,inclusions,macroscopic type,microscopic metallography and scanning electron microscopy.The results show that the chemical composition,inclusion and banded structure of the parts meet the standard requirements.The cracking reason of the parts is that the uneven distribution of carbides in the inner wall of the ball head seat surface causes stress concentration when the needle valve and the needle body seat surface collide,resulting in longitudinal cracking.

关 键 词：针阀体 断裂 R18CrNi8 

分 类 号：TK425[动力工程及工程热物理—动力机械及工程]