金属热处理 ›› 2022, Vol. 47 ›› Issue (2): 262-266.DOI: 10.13251/j.issn.0254-6051.2022.02.046

• 失效分析 • 上一篇    

20钢等径三通失效分析

李德君1,2, 高华3, 孔祥路3, 杨小平3, 李塔3, 董照远3, 张小佳1,2   

  1. 1.中国石油集团工程材料研究院有限公司, 陕西 西安 710077;
    2.石油管材及装备材料服役行为与结构安全国家重点实验室, 陕西 西安 710077;
    3.中石油煤层气有限责任公司, 北京 100028
  • 收稿日期:2021-10-15 修回日期:2021-12-28 出版日期:2022-02-25 发布日期:2022-04-01
  • 作者简介:李德君(1982—),男,高级工程师,博士,主要研究方向为高性能钢铁材料研究及工程失效分析,E-mail:lidejun352@cnpc.com.cn
  • 基金资助:
    中国石油天然气集团公司基础研究与战略储备项目(2018Z-03);中石油股份公司科技开发项目(2017F-19)

Failure analysis of 20 steel equal-diameter tee

Li Dejun1,2, Gao Hua3, Kong Xianglu3, Yang Xiaoping3, Li Ta3, Dong Zhaoyuan3, Zhang Xiaojia1,2   

  1. 1. CNPC Tubular Goods Research Institute, Xi'an Shaanxi 710077, China;
    2. State Key Laboratory of Performance and Structural Safety for Petroleum Tubular Goods and Equipment Materials, Xi'an Shaanxi 710077, China;
    3. Petrochina Coalbed Methane Company Limited, Beijing 100028, China
  • Received:2021-10-15 Revised:2021-12-28 Online:2022-02-25 Published:2022-04-01

摘要: 通过断口分析、化学成分分析、显微组织、布氏硬度以及电化学腐蚀性能测试,并结合该类三通的生产工艺,对发生脆断开裂的20钢计量撬等径三通进行了失效原因分析。结果表明,20钢无缝管采用液压冷胀成形工艺制造的三通未按标准要求进行正火或退火处理,加工硬化引起的材料脆化未能通过正确的热处理加以消除,导致三通本体缺陷容限的降低,诱发脆性断裂,并且冷变形还会使三通材料的电化学腐蚀性能显著下降,加速三通本体腐蚀,三通内壁上的腐蚀坑成为脆性断裂的裂纹源。建议加强对三通的质量监督和出厂检验。

关键词: 20钢等径三通, 脆性断裂, 腐蚀性能

Abstract: Failure causes of failed 20 steel equal-diameter tee used in a metering skid were investigated through the fracture analysis, chemical composition analysis, microstructure analysis, Brinell hardness and electrochemical corrosion test combining with the manufacture process of the tee. The results show that the tee made of 20 steel seamless pipe by hydraulic cold expansion forming process does not meet the standard requirements of normalizing or annealing treatment. The embrittlement caused by work hardening is not eliminated, which leads to the reduction of defect tolerance of the tee, and then the brittle fracture. Moreover, the electrochemical corrosion properties of the failed tee decline clearly due to the cold deformation, and the corrosion of inner wall of the tee is aggravated, and then the corrosion pit on inner wall of the tee becomes the crack source of brittle fracture. It is recommended to enhance the quality supervision and ex-factory inspection of the tee.

Key words: 20 steel equal-diameter tee, brittle fracture, corrosion resistance

中图分类号: