常减压蒸馏装置换热器法兰开裂原因分析

摘要

A large number of crackings of different lengths were found on the flanges of 15 heat exchangers in atmospheric-vacuum distillation unit in the turnaround, 2009. The testing concluded that the crackings were divided into two types： corrosion fatigue crack%某石化公司在2009年装置检修中发现15台高温换热器的所有接管法兰存在大量长短不等的径向裂纹。经检测发现裂纹分为两种：一种是腐蚀疲劳裂纹；一种是应力腐蚀裂纹。这二种裂纹的性质都属于环境敏感开裂。开裂法兰的化学成分中Cr，Ni和Ti的质量分数低于JB4728—2000《压力容器用不锈铜锻件标准》的下限，同时交货状态下没有固溶处理。针对产生环境敏感开裂的原因．提出了相应的预防措施．