煤焦油加氢精制装置高压换热器堆焊层开裂检验分析与维修工艺探讨  

Discussion on inspection analysis and maintenance process of weld overlay cracking ofhigh-pressure heat exchanger in coal tar hydro refining unit

作　　者：杨志刚 Yang Zhigang(Henan Boiler and Pressure Vessel Inspection Technology Research Institute,Zhengzhou Henan 450016,China)

机构地区：[1]河南省锅炉压力容器检验技术科学研究院,河南郑州450016

出　　处：《煤化工》2023年第4期72-75,共4页Coal Chemical Industry

摘　　要：针对某煤化工企业煤焦油加氢精制装置高压换热器管程出口接管堆焊层存在大量表面裂纹的问题,基于渗透检测、超声检测、硬度检测、铁素体含量检测等结果和设备运行记录,推测裂纹产生的原因为氯化物应力腐蚀开裂。经现场维修后,再次对缺陷部位进行检测,发现补焊区域周边出现新生裂纹。为防止设备损伤加重,将其进行返厂维修,最终检修合格。对比现场维修和返厂维修的工艺,推断未进行有效的焊前消氢处理是产生新裂纹的根本原因。In view of the problem that a large number of surface cracks existed in the weld overlay of the high-pressure heat exchanger tube side outlet nozzle of the coal tar hydro refining unit of a coal chemical enterprise,based on the results of penetrant testing,ultrasonic testing,hardness testing,ferrite content testing and equipment operation records,it was speculated that the cause of the cracks was chloride stress corrosion cracking.After on-site maintenance,the defect area was retested and new cracks were found around the repair welding area.To prevent further damage to the equipment,it was returned to the factory for maintenance,and the final maintenance was qualified.By comparing the on-site repair and return-to-factory repair processes,it was inferred that the failure to perform effective pre-weld hydrogen removal treatment was the fundamental cause of new cracks.

关 键 词：煤焦油 加氢精制 换热器 堆焊层 氯化物应力腐蚀开裂 消氢处理 

分 类 号：TE965[石油与天然气工程—石油机械设备]