金属热处理 ›› 2023, Vol. 48 ›› Issue (8): 265-271.DOI: 10.13251/j.issn.0254-6051.2023.08.043

• 失效分析 • 上一篇    下一篇

酸气后冷器封头开裂原因分析

刘民1, 鲁美朋1, 刘嘉晨2, 顾宝兰2, 郭静2, 孙跃军1, 宋明2   

  1. 1.辽宁工程技术大学 材料科学与工程学院, 辽宁 阜新 123000;
    2.中国特种设备检测研究院, 北京 100020
  • 收稿日期:2023-04-25 修回日期:2023-07-03 出版日期:2023-08-25 发布日期:2023-10-10
  • 通讯作者: 宋 明,教授级高工,博士,E-mail: songm214@foxmail.com
  • 作者简介:刘 民(1965—),男,副教授,主要研究方向为化工静设备状态评估,E-mail: 18340430635@163.com。

Analysis of cracking cause of acid gas post-cooler head

Liu Min1, Lu Meipeng1, Liu Jiachen2, Gu Baolan2, Guo Jing2, Sun Yuejun1, Song Ming2   

  1. 1. College of Materials Science and Engineering, Liaoning Technical University, Fuxin Liaoning 123000, China;
    2. China Special Equipment Inspection and Research Institute, Beijing 100020, China
  • Received:2023-04-25 Revised:2023-07-03 Online:2023-08-25 Published:2023-10-10

摘要: 某天然气净化厂酸气后冷器浮头式封头内壁出现鼓包和裂纹,采用宏观检验、化学成分分析、硬度测试、金相检验、能谱分析、断口分析及EBSD测试等方法,对鼓包和裂纹产生的原因进行了分析。结果表明,封头内壁鼓包和开裂为氢鼓包(HB)和氢致开裂(HIC)。由于该封头材料(20g钢)显微组织沿轧制方向呈(铁素体+珠光体)带状分布,且在1/2板厚位置存在因元素偏析所致的贝氏体组织和较多MnS夹杂物,而该封头的服役环境中含有湿H2S介质,与钢材发生电化学反应后产生了氢,氢在板厚1/2缺陷处聚集,导致了封头内壁的鼓包和开裂。

关键词: 20g钢, 湿H2S环境, 显微组织, MnS夹杂物, 氢致开裂, 鼓包

Abstract: Bulges and cracks appeared in the inner wall of floating head of acid gas post-cooler in a natural gas purification plant. The causes of bulges and cracks were analyzed by means of macroscopic examination, chemical composition analysis, hardness test, metallographic examination, energy spectrum analysis, fracture analysis and EBSD test. The results show that the bulge and cracking of the inner wall of the head are hydrogen bulge (HB) and hydrogen-induced cracking (HIC). Since the microstructure of the head material (20g steel) is banded ferrite+pearlite along the rolling direction, with bainite and more MnS inclusions appearing at the position of 1/2 plate thickness caused by element segregation, and the service environment of the head contains wet H2S medium which generates hydrogen after electrochemical reaction with the steel, then the hydrogen accumulates at the defects of 1/2 plate thickness, leading to bulge and cracking of the inner wall of the head.

Key words: 20g steel, wet H2S environment, microstructure, MnS inclusion, hydrogen-induced cracking, bulge

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