金属热处理 ›› 2020, Vol. 45 ›› Issue (2): 120-124.DOI: 10.13251/j.issn.0254-6051.2020.02.023

• 工艺研究 • 上一篇    下一篇

固溶时效对节镍型高氮奥氏体不锈钢组织的影响

常金宝1, 赵英利1, 嵇爽1, 张福利1, 杨现亮1, 裴建明2   

  1. 1. 河钢集团 钢研总院, 河北 石家庄 052165;
    2. 燕山大学 机械工程学院, 河北 秦皇岛 066000
  • 收稿日期:2019-08-25 出版日期:2020-02-25 发布日期:2020-04-03
  • 通讯作者: 嵇 爽(1992—),男,硕士,工程师,主要从事不锈钢研究工作,E-mail:779533356@qq.com
  • 作者简介:常金宝(1968—),男,教授级高工,主要从事钢铁材料的研发与生产,E-mail:hbisjs@126.com。

Effect of solution treatment and aging on microstructure of low-nickel high nitrogen austenitic stainless steel

Chang Jinbao1, Zhao Yingli1, Ji Shuang1, Zhang Fuli1, Yang Xianliang1, Pei Jianming2   

  1. 1. HESTEEL Group Technology Research Institute, Shijiazhuang Hebei 052165, China;
    2. College of Mechanical Engineering, Yanshan University, Qinhuangdao Hebei 066000, China
  • Received:2019-08-25 Online:2020-02-25 Published:2020-04-03

摘要:

对热轧态节镍型高氮奥氏体不锈钢进行固溶及时效处理,利用光学显微镜、电子背散射衍射,结合相图系统分析该材料固溶处理及时效后组织变化规律。结果表明,1050 ℃固溶处理后,试验钢基体为奥氏体,存在少量的铁素体,奥氏体晶粒形状偏等轴,晶粒内部存在大量孪晶。时效后,析出相主要为Cr2N、CrN、Cr23C6。在时效时间为5 h不变的条件下,温度由650 ℃升高至800 ℃,碳化物及氮化物数量呈现先增长后降低的趋势,在750 ℃时数量最多。而在750 ℃时效5~10 h范围内,随着时效时间的增加,析出相数量变化不大。析出相的析出过程为:先在晶界交叉处析出胞状析出物,随时间的延长,在晶界逐渐析出条状析出物,在晶内开始出现并逐渐长大,最终形成类珠光体的片层状析出。

关键词: 节镍型高氮奥氏体不锈钢, 固溶处理, 时效, 微观组织

Abstract:

Solid solution treatment and aging of hot rolled low-nickel high nitrogen austenitic stainless steel were carried out. Metallographic microscope, electron backscatter diffraction and phase diagram were used to systematically analyze the microstructure changes of the steel after solid solution treatment and aging. The results show that after solid solution treatment at 1050 ℃, the steel matrix is austenite with nearly equiaxial grains containing a large number of twins, and with a small amount of ferrite. After aging, the precipitated phases are mainly Cr2N, CrN, and Cr23C6. With the increase of aging temperature from 650 ℃ to 800 ℃ under the same aging time of 5 h, the amounts of carbides and nitrides increase first and then decrease, reaching to the maximum at 750 ℃. With the increase of aging time in the range of 5-10 h at 750 ℃, the amount of precipitates has little change. The precipitation process of the precipitated phases is as follows: Firstly, cellular precipitation occurs at the triple junctions of grain boundaries. With the extension of aging time, strip precipitates are gradually precipitated at the grain boundaries, and begin to appear and grow up inside the grains, finally form pearlite-like lamellar precipitates.

Key words: low-nickel high nitrogen austenitic stainless steel, solution treatment, aging, microstructure

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