蜡油加氢装置液位计下引线阀出口管失效分析  

Failure Analysis of Outlet Pipe of Downlead Valve for Level Gauge in the Wax Oil Hydrogenation Plant

作　　者：郭福平 吕运容 范志卿 李伟明 GUO Fu-ping;LÜYun-rong;FAN Zhi-qing;LI Wei-ming(College of Mechanical and Electrical Engineering,Guangdong University of Petrochemical Technology,Maoming 525000,China;Guangdong Provincial Key Laboratory of Petrochemical Equipment Fault Diagnosis,Maoming 525000,China)

机构地区：[1]广东石油化工学院机电工程学院,广东茂名525000 [2]广东省石化装备故障诊断重点实验室,广东茂名525000

出　　处：《石油化工设备》2022年第4期75-79,共5页Petro-Chemical Equipment

摘　　要：某石化企业蜡油加氢装置冷高分罐液位计的下引线阀出口管发生开裂失效,采用宏观观察、化学成分分析、硬度检测、垢物pH值检测、金相组织分析及断口电镜扫描能谱分析等方法,对出口管开裂失效原因进行分析。分析结果表明,该下引线阀出口管断裂原因为腐蚀疲劳开裂,裂纹起源于管内壁点蚀坑,进而发生硫化物应力腐蚀,并在循环弯曲载荷的作用下向外壁及轴向扩展,直到断裂。同时提出了防止出口管开裂泄漏的建议。The outlet pipe of the downlead valve of the level gauge on part of the cold high pressure separator broke and failed in the wax oil hydrogenation unit of a petrochemical enterprise.In order to find out the failure cause of the pipeline,macroscopic analysis,chemical composition analysis,hardness analysis,metallographic analysis and fracture analysis were conducted for the failed pipeline.The results show that the fracture of the outlet pipe of the downlead valve is caused by corrosion fatigue cracking,and the crack originates from the pitting pits on the inner wall of the pipe,and then sulfide stress corrosion occurs,under the action of cyclic bending load,it extends to outer wall and axial direction until it breaks.Recommendations were also proposed to prevent cracking of the outlet pipe.

关 键 词：出口管 下引线阀 腐蚀 疲劳 失效分析 

分 类 号：TQ055.807[化学工程]