多联换热器环缝接头断裂分析  

FRACTURE ANALYSIS OF CIRCUMFERENTIAL WELDED JOINT OF A MULTIPLE HEAT EXCHANGER

作　　者：黄嗣罗 林进华 雷小娣 Huang Siluo;Lin Jinhua;Lei Xiaodi(The Challenge Petrochemical Machinery Corporation,Maoming,Guangdong,P.C.525024)

机构地区：[1]茂名重力石化装备股份公司,广东茂名525024

出　　处：《乙烯工业》2025年第1期19-23,I0001,共6页Ethylene Industry

摘　　要：针对某石油化工厂的苯乙烯多联换热器在服役条件下环缝接头的断裂泄漏事故,通过裂纹形貌观察、小型工件模拟热处理试验、显微组织观察、硬度测试等试验手段,结合理论探讨,确定了事故原因,并提出了改进方案,最终获得了良好的效果。该设备运行过程中出现泄漏的根本原因是现有的焊后局部热处理工艺不足以完全消除这种厚板结构焊接残余应力,在设备服役过程中,工作应力与较高的环向残余应力叠加,局部应力超过材料自身的断裂强度而产生横向裂纹,并随着运行时间的延长,裂纹扩展,造成沿厚度方向的贯穿,最终导致出现泄漏事故。采用温度场均匀性更为良好的整体焊后热处理工艺,可消除残余应力,降低接头硬度,增强塑韧性,提高其在恶劣工况条件下的抗裂能力,避免此类开裂泄漏事故的发生。In view of the fracture leakage accident of the circumferential welded joint of a styrene multiple heat exchanger in a petrochemical plant under service conditions,the cause of the accident was determined combined with theoretical discussion through crack morphology observation,simulation heat treatment test for small workpieces,microstructure observation,hardness test and other test methods,some improvement schemes were proposed,and a good result was obtained.The root cause of the leakage during operation of the equipment is that the existing local post-welding heat treatment process can not completely eliminate the welding residual stress of this thick plate structure.During the service of the equipment,the working stress is superimposed on the high circumferential residual stress,and the local stress exceeds the breaking strength of the material itself,resulting in transverse cracks,which cause penetration along the thickness direction and eventually lead to leakage accidents.The overall post-welding heat treatment process with better temperature field uniformity can eliminate residual stress,reduce joint hardness,enhance ductility,improve its cracking resistance under harsh working conditions,and avoid the occurrence of such leakage accidents.

关 键 词：环焊缝 断裂分析 焊接残余应力 焊后热处理 

分 类 号：TG1[金属学及工艺—金属学]