金属热处理 ›› 2022, Vol. 47 ›› Issue (1): 125-129.DOI: 10.13251/j.issn.0254-6051.2022.01.021

• 材料研究 • 上一篇    下一篇

Ti微合金化对22MnB5热成形钢组织和性能的影响

朱赫男, 陈刚, 杨佳伟, 张志建   

  1. 江苏省沙钢钢铁研究院, 江苏 苏州 215600
  • 收稿日期:2021-06-01 修回日期:2021-08-26 出版日期:2022-01-25 发布日期:2022-02-18
  • 通讯作者: 张志建,高级工程师,博士,E-mail:zhangzj-iris@shasteel.cn
  • 作者简介:朱赫男(1993—),女,助理工程师,硕士,主要研究方向为钢铁材料开发及应用,E-mail:2372950322@qq.com。

Effect of Ti micro-alloying on microstructure and properties of 22MnB5 hot press forming steel

Zhu Henan, Chen Gang, Yang Jiawei, Zhang Zhijian   

  1. Institute of Research of Iron and Steel, Shasteel, Suzhou Jiangsu 215600, China
  • Received:2021-06-01 Revised:2021-08-26 Online:2022-01-25 Published:2022-02-18

摘要: 通过热膨胀试验、显微组织分析和硬度测试,分析了冷却速率和Ti元素对两种22MnB5热成形试验钢相变温度、显微组织、析出相以及硬度等的影响,并绘制了CCT曲线。结果表明,当冷却速率低于5 ℃/s时,试验钢的显微组织主要为铁素体和珠光体;冷却速率达到5 ℃/s后开始形成贝氏体;冷却速率达到30 ℃/s时,获得单一马氏体组织。Ti微合金化可降低Ms点,并通过析出Ti(C, N) 相细化奥氏体晶粒,从而获得细小的马氏体板条,产生的析出强化和细晶强化效应提高了试验钢的强度。

关键词: 冷却速率, Ti, 热成形钢, CCT曲线

Abstract: Through thermal expansion test, microstructure analysis and hardness test, the effect of cooling rate and Ti element on the phase transformation temperature, microstructure, precipitated phase and hardness of two 22MnB5 hot forming steels was analyzed, and then the CCT curves was obtained. The results show that the microstructure of the tested steels are composed of ferrite and pearlite when the cooling rate is lower than 5 ℃/s; bainites appear when the cooling rate reaches 5 ℃/s, and the transformation products are totally martensites when the cooling rate reaches 30 ℃/s. Ti micro-alloying deceases the Ms temperature, and the precipitation of Ti(C, N) phase refines the austenite grain size and therefore the lath martensites, which improves the strength of the tested steel by the effects of precipitation strengthening and fine grain strengthening.

Key words: cooling rate, titanium, hot press forming steel, CCT curve

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