摘要
某厂中变一段换热器新换上的0Cr18Ni9不锈钢制U形膨胀节仅运行2个月即发生突然断裂。检验表明,断裂起始于膨胀节波峰外壁,属高应力下应力腐蚀开裂。外保温材料中含Cl-、S、Na等组份,并较长时间被水浸渍;膨胀节材料已整体严重脆化,显微组织中马氏体所占比例达到50%,显微硬度达到Hv400左右;焊接质量差;膨胀节波峰处应力较高;介质中含氢等是引起破坏的主要原因。本文还提出防止和控制上述问题的技术措施。
The fracture accident of a new U - type expansion joint of middle transform first - section heat exchanger occurred suddenly in service for only two months, it was made of type 0Cr18Ni9 austenitic stainless steel . Test showed that, above fracture originated from out - wall of the expansion joint and was stress corrosion cracking at high stress level. Causes of the accident were： out - insulating - materials contained Cl^-, S, Na , etc , and were soaked by water for longer time; expansion joint materials whole were embrittle seriously and its martensite content was about 50% and micro - hardness were about Hv400; welding quality was inferior; Stress on wave crest was higher;there was hydrogen in medium and so on . The corresponding prevention measures were put forward.
出处
《压力容器》
北大核心
2007年第5期36-40,共5页
Pressure Vessel Technology
关键词
U形膨胀节
应力腐蚀开裂
防治措施
U - type expansion joint
stress corrosion cracking
prevention measures
作者简介
张维波，高工，从事化工装置技术工作和管理工作，通讯地址：吉林市龙潭大街9号吉林石化公司机动处。
