催化裂化再生系统腐蚀开裂失效分析与三效剂应用  

Stress Corrosion Cracking Failure Analysis of FCC Regenerator Unit and Application of New-type Muitifunction catalyst

作　　者：吴俊升[1] 李晓刚[1] 陈华[1] 李明[1] 

机构地区：[1]北京科技大学材料科学与工程学院腐蚀与防护中心,北京100083

出　　处：《金属热处理》2007年第z1期163-166,共4页Heat Treatment of Metals

摘　　要：通过对催化裂化再生系统开裂构件的无损检测、化学成分分析、金相检验、断口观察及介质环境等分析表明,催化裂化再生系统由于设备壁温长期低于烟气露点温度,在NOx-SOx-H2O烟气结露形成的酸性腐蚀介质和残余应力的共同作用下,发生了硝酸盐应力腐蚀开裂。现场试验表明,使用转硫降氮助燃三效催化剂后再生烟气中SO_X平均脱除率达72.86%,NO_X脱除率达92.01%,可有效降低烟气露点温度,防止催化裂化再生系统设备硝酸盐应力腐蚀的发生。The cause and principle of the cracking failure of the regenerator devices of fluid catalytic and cracking unit (FCCU) in a Chinese refinery were analyzed.The results of chemical composition,fracture surface examination, nondestructive detection,microstructure and corrosion mediums analysis show that the failure is caused by the dew point nitrate stress corrosion cracking (SCC).For a long operation period,the wall temperature of the regenerator in the FCCU was below the fume dew point.As a result,an acid fume NO_x-SO_x-H_2O medium presented on the surface, resulting in stress corrosion cracking of the component with high residual stress.The commercial application results of a new-type multifunction catalyst indicate that the removal efficiency of SO_2 and NO_x in the regeneration unit fume have reached 72.86% and 92.01% respectively.Therefore,the dew point of fume can be decreased and the SCC of FCCU can be avoided by using of this new type catalyst.

关 键 词：催化裂化 应力腐蚀开裂 三效剂 

分 类 号：TG15[金属学及工艺—热处理]