金属热处理 ›› 2022, Vol. 47 ›› Issue (10): 46-51.DOI: 10.13251/j.issn.0254-6051.2022.10.008

• 材料研究 • 上一篇    下一篇

稀土La对NbC在700 ℃等温析出行为的影响

雷梓华1,2, 方琪1,2,3, 金自力1,2,3, 孙伟1,2,3, 熊东东1,2   

  1. 1.内蒙古科技大学 材料与冶金学院, 内蒙古 包头 014010;
    2.内蒙古自治区新金属材料重点实验室, 内蒙古 包头 014010;
    3.白云鄂博共伴生矿资源高效综合利用省部共建协同创新中心, 内蒙古 包头 014010
  • 收稿日期:2022-05-26 修回日期:2022-08-22 出版日期:2022-10-25 发布日期:2022-12-15
  • 通讯作者: 方 琪,教授,博士,E-mail:fq195461162@126.com
  • 作者简介:雷梓华(1996—),男,硕士研究生,主要研究方向为优质资源在微合金高强钢中的开发与应用,E-mail: 912015759@qq.com。
  • 基金资助:
    内蒙古自治区自然科学基金(2019MS05051);内蒙古自治区科技重大专项(zdzx2018032)

Effect of rare earth La on isothermal precipitation behavior of NbC at 700 ℃

Lei Zihua1, 2, Fang Qi1,2,3, Jin Zili1,2,3, Sun Wei1,2,3, Xiong Dongdong1,2   

  1. 1. School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China;
    2. Key Laboratory of New Metal Materials of Inner Mongolia Autonomous Region, Baotou Inner Mongolia 014010, China;
    3. Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Baotou Inner Mongolia 014010, China
  • Received:2022-05-26 Revised:2022-08-22 Online:2022-10-25 Published:2022-12-15

摘要: 对不同稀土La含量(0、0.0006%和0.0048%)的Nb微合金化试验钢进行1250 ℃固溶+700 ℃盐浴等温处理,研究了在铁素体区等温不同时间下,稀土对NbC析出行为的影响。结果表明,在钢中加入稀土La能够促进Nb在1250 ℃时的固溶,未溶第二相数量减少;700 ℃等温时,在析出开始阶段,稀土的促进作用相对较弱,随着等温时间的延长,稀土的促进作用逐渐显著。稀土La使NbC析出动力学曲线左移,加入0.0048%La使NbC析出开始时间由199 s缩短至125 s,结束时间由35 183 s缩短至29 128 s;等温时间为104.25 s时,与不加稀土时相比,添加稀土后试验钢在铁素体区700 ℃等温104.25 s后析出的NbC第二相尺寸小,不加稀土时NbC尺寸主要分布在10~20 nm,占42.8%,而添加0.0006%La和0.0048%La时,NbC尺寸主要分布在1~10 nm之间,分别占53.6%和64.3%,表明稀土La的添加使NbC尺寸得到了明显的细化。

关键词: La, 微合金钢, NbC, 析出动力学

Abstract: By solution treated at 1250 ℃ and salt bath isothermally treated at 700 ℃, the effect of rare earth on isothermal precipitation behavior of NbC in Nb-microalloyed steels with adding La of 0, 0.0006% and 0.0048%, respectively, in the ferrite region for different time was studied. The results show that the addition of rare earth La into the steel can promote the dissolving of niobium at 1250 ℃ and reduce the number of undissolved second phases. When isothermally treated at 700 ℃, the promotion effect of rare earth is relatively weak at the beginning of precipitation, and gradually becomes significant with the increase of isothermal time. Rare earth La makes the NbC precipitation kinetic curve shift to the left. The addition of 0.0048% rare earth reduces the precipitation start time from 199 s to 125 s, and the end time from 35 183 s to 29 128 s. When isothermally treated at 700 ℃ for 104.25 s, the size of the second phase NbC precipitated in the ferrite area of the steel containing rare earth is smaller compared with that in the steel without rare earth. The size of the precipitated NbC in the steel without La is mainly in the range of 10-20 nm, accounting for 42.8%, while the size of the precipitated NbC in the steel containing 0.0006%La and 0.0048%La is mainly in the range of 1-10 nm, accounting for 53.6% and 64.3%, respectively, which indicates that the addition of rare earth La can refine the size of NbC significantly.

Key words: La, microalloyed steel, NbC, precipitation kinetics

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