某炼油厂常减压装置换热器腐蚀情况分析  

Corrosion Analysis on Crude Vacuum Distillation Unit's Heat Exchangers in Petrochemical Company

作　　者：杨东平[1] 胥聪敏[1] 李辉辉[1] 

机构地区：[1]西安石油大学材料科学与工程学院材料加工工程重点实验室,陕西西安710065

出　　处：《热加工工艺》2014年第18期225-229,共5页Hot Working Technology

基　　金：陕西省教育厅专项科研计划项目(2013JK0895);陕西省重点学科专项资金资助项目(ys37020203)

摘　　要：针对某公司500万吨/年常减压装置换热器E-502设备在使用过程中发生的腐蚀失效问题,通过金相组织观察、SEM、EDS及XRD分析,研究了换热管的腐蚀失效原因及机理。结果表明:换热管内、外表面均发生了局部腐蚀,且外表面要比内表面腐蚀严重;换热管外表面腐蚀产物中的主要物相有α-FeO(OH)、Fe2O3和Fe3O4,内表面腐蚀产物有大量非晶体,以及少量Fe3O4和Fe2O3;E-502换热器的腐蚀作用主要来源于溶解氧对碳钢的电化学腐蚀及含盐污水中高含量Cl-的吸附、渗入膜内破坏膜的保护性,引起了坑蚀核,在自催化作用下导致孔蚀破坏。Based on the corrosion failure problem of 5 million t/year crude vacuum distillation unit’s heat exchanger E-502 equipment of a petrochemical refinery in the process of service, the corrosion failure reason and mechanism of heat exchange tube were investigated by microstructure observation, SEM, EDS and XRD analysis. The results indicate that the heat exchange tubes’ inside and outside have local corrosion, and of the corrosion of outer surface is more serious than that of inner surface. The main corrosion products of heat exchange tube of outer surface have α-FeO（OH）, Fe2O3 and Fe3O4. The inner surface has lots of amorphous and a small amount of Fe3O4 and Fe2O3. E-502 heat exchangers’ corrosion effect mainly originates from the electrochemical corrosion of dissolved oxygen and the damage of membrane protective by adsorption and seeping into membrane of high levels of Cl-, which can cause the pitting corrosion nuclear, under the action of autocatalytic,as a result of pitting corrosion damage.

关 键 词：换热器 换热管 点腐蚀 腐蚀产物 

分 类 号：TG113.2[金属学及工艺—物理冶金]