金属热处理 ›› 2022, Vol. 47 ›› Issue (12): 56-61.DOI: 10.13251/j.issn.0254-6051.2022.12.009

• 工艺研究 • 上一篇    下一篇

热处理对稀土5Cr钢组织及析出相的影响

李涛1,2, 许涛2, 韩强1, 孙昊1, 白岩松1, 梁占磊1   

  1. 1.内蒙古科技大学 材料与冶金学院, 内蒙古 包头 014010;
    2.内蒙古科技大学 分析测试中心, 内蒙古 包头 014010
  • 收稿日期:2022-07-06 修回日期:2022-10-11 出版日期:2022-12-25 发布日期:2023-01-05
  • 通讯作者: 韩 强,副教授,硕士, E-mail:qiang.han163@163.com
  • 作者简介:李 涛(1974—),女,教授,博士,主要研究方向为先进金属材料的基础研究及组织控制、金属材料的自然环境腐蚀与防护,E-mail:836450192@qq.com。
  • 基金资助:
    内蒙古自然科学基金(2021LHMS05028);内蒙古科技计划(2020GG0207)

Effect of heat treatment on microstructure and precipitates of 5Cr steel with RE addition

Li Tao1,2, Xu Tao2, Han Qiang1, Sun Hao1, Bai Yansong1, Liang Zhanlei1   

  1. 1. School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China;
    2. Instrumental Analysis Center, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China
  • Received:2022-07-06 Revised:2022-10-11 Online:2022-12-25 Published:2023-01-05

摘要: 以稀土5Cr钢为对象,研究了热处理工艺(870、900、930 ℃保温50 min水淬,670、690、710 ℃保温90 min回火)对其组织及第二相析出行为的影响。结果表明,试验钢经870 ℃淬火后,组织未完全奥氏体化;随着淬火温度的升高,试验钢完全奥氏体化,原始奥氏体平均晶粒尺寸从900 ℃的13.49 μm增大到930 ℃的15.01 μm,且组织均匀性明显下降。合适的淬火温度为900 ℃。在670~710 ℃回火后,组织分布为回火屈氏体、回火屈氏体+回火索氏体、回火索氏体。回火后第二相为分布在基体上的Cr7C3碳化物及在界面聚集的Cr23C6碳化物。随着回火温度的升高,Cr23C6碳化物比例逐渐增加。为避免回火过程中M23C6型碳化物的聚集和粗化,合适的回火温度为690 ℃。

关键词: 稀土5Cr钢, 热处理, 组织, 析出相

Abstract: Taking 5Cr steel with RE addition as the object, the effect of heat treatment (water quenching at 870, 900, 930 ℃ for 50 min , and then tempering at 670, 690, 710 ℃ for 90 min) on microstructure and second-phase precipitation behavior of the tested steel was studied. The results show that after quenching at 870 ℃, the structure is not completely austenitized. The tested steel is completely austenitized with the increase of quenching temperature, and the prior-austenite average grain size is increased from 13.49 μm at 900 ℃ to 15.01 μm at 930 ℃, while the microstructure uniformity is obviously reduced. By selecting the proper quenching temperature as 900 ℃, and after tempering at 670-710 ℃, the microstructure is tempered troostite, tempered troostite + tempered sorbite and tempered sorbite in turn. The second phases after tempering are Cr7C3 carbide distributed on the matrix and Cr23C6 carbide aggregated at the interface. With the increase of tempering temperature, the proportion of Cr23C6 carbide increases gradually. In order to avoid the aggregation and coarsening of M23C6 carbides during tempering, the appropriate tempering temperature is 690 ℃.

Key words: 5Cr steel with RE addition, heat treatment, microstructure, precipitates

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