单塔汽提装置汽提塔封头开裂原因分析  

Cause Analysis of Cracking on Stripper Head in Single Stripping Tower Unit

作　　者：符长军[1] 王立坤[1] 周全辉 FU Changjun;WANG Likun;ZHOU Quanhui(CNPC Dushanzi Petrochemical Company,Dushanzi 83399,China)

机构地区：[1]中国石油天然气股份有限公司独山子石化分公司,新疆独山子833699

出　　处：《石油化工腐蚀与防护》2018年第4期47-52,共6页Corrosion & Protection In Petrochemical Industry

摘　　要：某石化分公司检验时发现汽提塔上封头外壁与筒体焊接的焊缝附近出现多处裂纹,通过取样进行宏观检查、化学成分分析、硬度试验、金相检验、扫描电镜分析及能谱分析,并结合保温材料Cl^-检测,认为:在封头外部保温层含Cl^-和水的腐蚀环境中,封头焊缝区综合应力和敏感介质共同作用,使得敏化的奥氏体不锈钢发生晶界开裂,最终导致封头与筒体焊接的热影响区发生了沿晶型应力腐蚀开裂。A large number of cracks were found near the weld between outer wall of the upper head and cylinder body during stripper inspection. Samples were analyzed by macroscopic examination, chemical composition analysis, hardness test, metallographic examination, scanning electron microscope and energy- spectrum analysis. Combined with C1 detection in thermal insulation material, it was concluded that sensitive austenitic stainless steel cracked at the crystalline interface by corrosion environment with C1 and water in external thermal insulation layer, as well as the joint effects of multiple stresses in the head welding zone and sensitive media, which resulted in inter-granular stress corrosion cracks occurred in welding heat-affected zone between head and cylinder body.

关 键 词：汽提塔 封头 应力腐蚀开裂 

分 类 号：TE96[石油与天然气工程—石油机械设备]