金属热处理 ›› 2020, Vol. 45 ›› Issue (12): 189-193.DOI: 10.13251/j.issn.0254-6051.2020.12.037

• 组织与性能 • 上一篇    下一篇

蒸汽管道用P91钢管长时服役后的组织和力学性能

齐全友1, 杨旭2   

  1. 1.内蒙古国华呼伦贝尔发电有限公司, 内蒙古 呼伦贝尔 021025;
    2.中国特种设备检测研究院, 北京 100029
  • 收稿日期:2020-10-16 出版日期:2020-12-25 发布日期:2021-01-14
  • 作者简介:齐全友(1968—),男,工程师,主要从事电厂安全生产、经营管理工作,E-mail: quanyou.qi@chnenergy.com.cn

Microstructure and mechanical properties of P91 steel steam pipe after long service

Qi Quanyou1, Yang Xu2   

  1. 1. Inner Mongolia Guohua Hulunbeier Power Generation Co., Ltd., Hulunbeier Inner Mongolia 021025, China;
    2. China Special Equipment Inspection and Research Institute, Beijing 100029, China
  • Received:2020-10-16 Online:2020-12-25 Published:2021-01-14

摘要: 利用光学显微镜、扫描电镜和透射电镜对比研究了服役38 000 h后P91钢管弯管段和直管段的微观组织,测试了其力学性能,并分析了弯管段软化原因。结果表明:相比直管段,弯管段组织中大量铁素体的存在是其强度、硬度大幅下降的主要原因。分析认为弯管段中的铁素体是由于弯管过程中施加的二次变形导致马氏体内能增加,使得回火过程中马氏体再结晶形成。

关键词: P91钢管, 显微组织, 力学性能, 软化机制

Abstract: Microstructure of both the straight and the elbow section of P91 steel steam pipe served for 38000 h was studied by means of optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM), and corresponding mechanical properties were tested. The results show that the existence of a large amount of ferrite in the elbow microstructure is the main reason for sharp drop of its strength and hardness. It is concluded that the ferrite in the elbow is formed by the recrystallization of martensite during tempering due to the increase of energy caused by secondary deformation during bending.

Key words: P91 steel pipe, microstructure, mechanical properties, softening mechanism

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