石油化工设备技术 ›› 2019, Vol. 40 ›› Issue (5): 10-13.doi: 10.3969/j.issn.1006-8805.2019.05.004

• 腐蚀与防护 • 上一篇    下一篇

0Cr18Ni10Ti不锈钢换热器管束腐蚀开裂分析

马红杰   

  1. 中国石油天然气股份有限公司独山子石化分公司研究院,新疆 独山子 833699
  • 收稿日期:2019-05-09 接受日期:2019-08-25 出版日期:2019-09-15 发布日期:2019-11-20
  • 作者简介:马红杰,男,2005年毕业于中国石油大学材料科学与工程专业,硕士,主要从事腐蚀监检测与防护工作,高级工程师。Email:yjy_mhj@petrochina.com.cn

Analysis on Corrosion Cracking of Tube Bundles in 0Cr18Ni10Ti Stainless Steel Heat Exchangers

Ma Hongjie   

  1. PetroChina Dushanzi Petrochemical Company, Dushanzi, Xinjiang, 833699
  • Received:2019-05-09 Accepted:2019-08-25 Online:2019-09-15 Published:2019-11-20

摘要: 某石化公司裂解燃料油加氢装置汽提塔进料换热器0Cr18Ni10Ti不锈钢管束发生腐蚀开裂。采用宏观腐蚀调查、光谱分析、金相分析、SEM观察、EDS分析、XRD分析及腐蚀介质分析等方法,对腐蚀失效换热管的腐蚀情况、化学成分、金相组织、腐蚀产物进行了检测分析,结果表明,换热管固溶处理效果不佳,存在一定的残余应力,断口为解理断裂形貌,裂纹呈穿晶扩展,具有典型的应力腐蚀开裂特征。分析结果认为,换热管的腐蚀开裂为氯化物应力腐蚀开裂,而其本身的残余应力及壳程冷低分油中的氯化物为0Cr18Ni10Ti奥氏体不锈钢换热管发生应力腐蚀开裂提供了必要条件。

关键词: 不锈钢, 换热管, 腐蚀产物, 裂纹, 应力腐蚀开裂

Abstract: Corrosion cracking occurred on the tube bundles in 0Cr18Ni10Ti stainless steel stripping tower exchangers of pyrolysis fuel oil hydrogenation unit in a petrochemical company. The macro corrosion investigation, spectral analysis, metallographic analysis, SEM observation, EDS analysis, XRD analysis and corrosion medium analysis methods are adopted to examine and analyze the corrosion condition, chemical composition, metallographic structure and corrosion products. The results showed that the solution treatment effect of heat exchange tube was not good; there was certain amount of residual stress; the fracture was cleavage fracture morphology; the crack presented transcrystalline expanding. These were the characteristics of typical stress corrosion cracking. The analysis results indicated that the corrosion cracking of the heat exchange tube was chloride stress corrosion cracking and the residual stress of heat exchange tube itself and chloride of cold high oil for 0Cr18Ni10Ti stainless steel pipe provided necessary conditions for stress corrosion cracking.

Key words: stainless steel, heat exchanger tube, corrosion products, crack, stress corrosion cracking/SCC