金属热处理 ›› 2024, Vol. 49 ›› Issue (10): 234-238.DOI: 10.13251/j.issn.0254-6051.2024.10.038

• 材料研究 • 上一篇    下一篇

微量稀土Ce对DX51D+Z低碳钢连续冷却转变曲线的影响

杨维宇1,2, 魏晓东1,2, 白雅琼1,2, 张晓峰1,2, 郎荣彪1,2   

  1. 1.内蒙古包钢钢联股份有限公司 技术中心, 内蒙古 包头 014010;
    2.内蒙古自治区稀土钢产品研发重点实验室, 内蒙古 包头 014010
  • 收稿日期:2024-04-29 修回日期:2024-08-12 出版日期:2024-11-28 发布日期:2024-11-28
  • 作者简介:杨维宇(1982—),男,高级工程师,硕士,主要研究方向为板材应用技术及金属材料失效分析,E-mail: 153884843@qq.com

Effect of trace rare earth Ce on continuous cooling transformation curve of DX51D+Z low carbon steel

Yang Weiyu1,2, Wei Xiaodong1,2, Bai Yaqiong1,2, Zhang Xiaofeng1,2, Lang Rongbiao1,2   

  1. 1. Technical Center, Inner Mongolia Baotou Steel Union Co., Ltd., Baotou Inner Mongolia 014010, China;
    2. Key Laboratory of Rare Earth Steel Products Research and Development, Baotou Inner Mongolia 014010, China
  • Received:2024-04-29 Revised:2024-08-12 Online:2024-11-28 Published:2024-11-28

摘要: 利用Formaster-F型全自动相变仪,结合显微组织分析,绘制了添加和未添加稀土元素Ce的DX51D+Z低碳钢的连续冷却相变曲线,研究了不同冷速下稀土对DX51D+Z钢连续冷却相变点和显微组织的影响。结果表明,微量稀土Ce(9×10-6)的添加,使DX51D+Z钢的Ac1相变点温度降低3 ℃,Ac3相变点温度升高9 ℃,增大了缓慢加热过程中α-Fe→γ-Fe相变区间;当冷却速度为0.05~2 ℃/s时,微量稀土Ce对试验钢的相变开始和终止温度影响不大;当冷速≥5 ℃/s时,微量稀土Ce使试验钢的相变终止温度降低,扩大了铁素体+珠光体、铁素体+贝氏体的相变区间,使静态CCT曲线向左下方移动;在0.1~20 ℃/s冷速范围内,含稀土Ce的试验钢铁素体晶粒度比不含稀土的高0.2~0.4级,且晶粒尺寸分布更均匀。

关键词: 稀土Ce, DX51D+Z低碳钢, CCT曲线, 微观组织

Abstract: Continuous cooling phase transformation curves of the DX51D+Z low carbon steel with and without rare earth element Ce were drawn by Formaster-F automatic phase transformation instrument combined with microstructure analysis. The effects of rare earth on the continuous cooling phase transformation points and microstructure of the DX51D+Z steel at different cooling rates were studied. The results show that the addition of trace rare earth Ce (9×10-6) reduces the Ac1 transformation point temperature of the DX51D+Z steel by 3 ℃ and increases the Ac3 transformation point temperature by 9 ℃, increasing the phase transformation interval from α-Fe→γ-Fe during slow heating. When the cooling rate is 0.05-2 ℃/s, the trace rare earth Ce has little effect on the the starting and ending temperature of phase transformation of the tested steel. When the cooling rate is greater than 5 ℃/s, the trace rare earth Ce reduces the phase transformation termination temperature, expands the phase transformation range of ferrite+pearlite and ferrite+bainite, and shifts the static CCT curve to the lower left. Within the cooling rate range of 0.1-20 ℃/s, the grain size grade of the tested steel with rare earth Ce is 0.2-0.4 higher than that without rare earth, and the grain size distribution is more uniform.

Key words: rare earth Ce, DX51D+Z low-carbon steel, CCT curve, microstructure

中图分类号: