调节阀内部弹性垫圈开裂分析  

Cracking analysis of elastic washer inside control valve

作　　者：郑明光 侯艳宏 熊江 ZHENG Mingguang;HOU Yanhong;XIONG Jiang(CNOOC Huizhou Petrochemicals Company Limited,Huizhou 516086,China)

机构地区：[1]中海油惠州石化有限公司,广东惠州516086

出　　处：《石油化工腐蚀与防护》2023年第2期49-53,共5页Corrosion & Protection In Petrochemical Industry

基　　金：中海油惠州石化科研项目“原油劣质化下的一期炼油装置腐蚀研究”(HZSH-SCXKJ 2020008)。

摘　　要：弹性垫圈可防止螺栓松动,增强密封性,通常采用弹簧钢或不锈钢等特殊材质制造。调节阀内部弹性垫圈受到周期性载荷应力作用和硫化氢腐蚀,在短期服役后出现断裂,一次断口呈现典型的脆性断裂特征,垫圈内外均有裂纹。根据金相组织分析和扫描电镜分析结果,结合垫圈服役环境分析,认为高温高压环境下由氢气导致氢脆的可能性极小,垫圈断裂的根本原因在于垫圈表面镀铬时氢原子进入钢中,垫圈在后续加工过程中未进行消氢处理或消氢不彻底,造成残留氢在高温条件下短时间内积聚导致垫圈断裂。Elastic washer can prevent the bolt from loosening and enhance the sealing performance.It is usually made of special materials such as spring steel or stainless steel.The elastic washer inside control valve is subject to periodic load stress and hydrogen sulfide corrosion,so it breaks after short-term service.The primary fracture shows typical brittle fracture feature,and there are cracks inside and outside the washer.According to the results of metallographic structure analysis and scanning electron microscope analysis,combined with service environment of the washer,it is considered that the possibility of hydrogen embrittlement caused by hydrogen under high temperature and high pressure environment is very small.The root cause for broken washer is that hydrogen atoms enter the steel when washer surface is chrome-plated,however the washer hasn’t been through hydrogen removal treatment or hydrogen removal is incomplete during subsequent processing,thus causing accumulation of residual hydrogen in a short time under high temperature condition,eventually leading to washer fracture.

关 键 词：调节阀 弹簧垫圈 断裂 氢脆 

分 类 号：TE980[石油与天然气工程—石油机械设备] TG115[金属学及工艺—物理冶金]