金属热处理 ›› 2020, Vol. 45 ›› Issue (3): 59-63.DOI: 10.13251/j.issn.0254-6051.2020.03.012

• 材料研究 • 上一篇    下一篇

Nb和时效时间对热轧中锰TRIP钢中P偏聚的影响

李岩1, 付吉雪1, 赵增武1, 定巍1,2   

  1. 1. 内蒙古科技大学 内蒙自治区白云鄂博矿多金属资源综合利用重点实验室, 内蒙古 包头 014010;
    2. 内蒙古科技大学 材料与冶金学院, 内蒙古 包头 014010
  • 收稿日期:2019-09-15 出版日期:2020-03-25 发布日期:2020-04-03
  • 作者简介:李 岩(1983—),女,副教授,博士,主要从事钢材性能改性研究,E-mail:kenshin110@163.com。
  • 基金资助:

    国家自然科学基金(51364033,51304120),内蒙古自然科学基金(2019MS05014)

Effect of Nb and aging time on phosphorus segregation in hot-rolled medium-manganese TRIP steel

Li Yan1, Fu Jixue1, Zhao Zengwu1, Ding Wei1,2   

  1. 1. Key Laboratory of Integrated Exploitation of Bayan Obo Multi-metal Resources, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China;
    2. School of Materials and Metallurgy Engineering, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China
  • Received:2019-09-15 Online:2020-03-25 Published:2020-04-03

摘要:

热轧态中锰TRIP钢首先经650 ℃退火2 h,随后在550 ℃进行等温时效热处理,采用场发射扫描电镜(FE-SEM)研究该钢中P的偏聚和时效析出行为的变化情况。结果表明,中锰TRIP钢中P在晶界的偏聚是一种非平衡偏聚现象,临界时间约为50 h,与理论计算结果48 h较为吻合。在局部偏聚区域内,C与P存在共偏聚的关系,即P偏聚量高的地方,C含量也高。而合金元素Nb具有抑制P偏聚的效果,在20~70 h时效时间内,可以相对降低6.57%~19.5%的最大P偏聚量。根据电子背散射衍射(EBSD)菊池线分析,P偏聚量低于2.28at%时,P为固溶状态,高于2.28at.%时,P为析出状态。

关键词: 中锰钢, 等温时效, P偏聚, 非平衡偏聚, 临界时间

Abstract:

The phosphorus segregation and precipitation behavior in a hot-rolled medium-manganese TRIP steel treated with 650 ℃ annealing for 2 h+550 ℃ isothermal aging were investigated by field emission scanning electron microscopy (FE-SEM). The results show that the grain boundary segregation of P is a non-equilibrium phenomenon. The critical time is about 50 h, which is consistent with the theoretical calculation result of 48 h. C and P co-segregation exists in certain local regions, where the segregations of C and P are both higher. The alloying element Nb has an inhibitory effect on phosphorus segregation in the steel, the maximum P segregation content can be reduced relatively by 6.57%-19.5% within the aging time of 20-70 h. According to the Kikuchi line analysis in the electron backscatter diffraction, P is in solid solution when the content of segregation is less than 2.28at%, while P will be in the precipitated phase when the content of segregation is more than 2.28at%.

Key words: medium-manganese steel, isothermal aging, phosphorus segregation, non-equilibrium segregation, critical time

中图分类号: