金属热处理 ›› 2025, Vol. 50 ›› Issue (9): 68-75.DOI: 10.13251/j.issn.0254-6051.2025.09.011

• 组织与性能 • 上一篇    下一篇

拉伸温度对25Cr3Mo3NiNb钢屈服强度的影响

孙玉晓1, 涂明金2, 陈献刚2, 王星2, 刘科虹2, 刘晓辰1, 李玮2,3   

  1. 1.内蒙古科技大学 材料科学与工程学院, 内蒙古 包头 014010;
    2.内蒙古北方重工业集团有限公司, 内蒙古 包头 014010;
    3.内蒙古科技大学 分析测试中心, 内蒙古 包头 014010
  • 收稿日期:2025-04-05 修回日期:2025-07-10 出版日期:2025-09-25 发布日期:2025-10-13
  • 通讯作者: 李 玮,副教授,博士,E-mail: liwei_imust@126.com
  • 作者简介:孙玉晓(1999—),女,硕士研究生,主要研究方向为钢铁材料组织与性能,E-mail: sunyuxiaozhk@163.com。
  • 基金资助:
    内蒙古自治区科技计划(2021GC0141);内蒙古自治区教育厅冶金工程一流学科科研专项(YLXKZX-NKD-001)

Effect of tensile temperature on yield strength of 25Cr3Mo3NiNb steel

Sun Yuxiao1, Tu Mingjin2, Chen Xiangang2, Wang Xing2, Liu Kehong2, Liu Xiaochen1, Li Wei2,3   

  1. 1. School of Materials Science and Engineering, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China;
    2. Inner Mongolia North Heavy Industries Group Co., Ltd., Baotou Inner Mongolia 014010, China;
    3. Analysis and Testing Centre, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China
  • Received:2025-04-05 Revised:2025-07-10 Online:2025-09-25 Published:2025-10-13

摘要: 对经淬火+二次回火处理后的25Cr3Mo3NiNb钢进行不同温度(100~700 ℃)的拉伸试验,研究拉伸温度对其屈服强度的影响。结果表明,25Cr3Mo3NiNb钢热处理后,Mo元素以M2C型碳化物的形式存在,随拉伸温度升高,M2C型碳化物发生粗化和长大,马氏体板条宽度增大,屈服强度降低,从943 MPa降至389 MPa。500~700 ℃拉伸温度下,屈服强度大幅下降。500~700 ℃拉伸时,M2C型碳化物析出强化贡献降低3.67 MPa;位错强化贡献降低11.78 MPa,马氏体板条晶界强化贡献降低51.39 MPa,Mo固溶强化贡献降低267.29 MPa,可见Mo元素的固溶强化是影响25Cr3Mo3NiNb钢高温强度的主要因素。在二次回火态25Cr3Mo3NiNb钢中,每固溶1%质量分数Mo元素,在100、500、600和700 ℃拉伸温度下,强度增量分别为23.38、140.94、126.83和32.42 MPa,可见Mo元素在600 ℃之前具有良好的固溶强化效果,700 ℃时固溶强化效果减弱。

关键词: 高强钢, 拉伸温度, 固溶强化, 屈服强度, M2C型碳化物

Abstract: Tensile tests at different temperatures (100-700 ℃) were carried out on 25Cr3Mo3NiNb steel after quenching+double tempering treatment to study the effect of tensile temperature on its yield strength. The results show that after heat treatment, Mo element of the 25Cr3Mo3NiNb steel exists in the form of M2C-type carbides. As the tensile temperature increases, the M2C-type carbides coarsen and grow, the width of martensite laths increases, and the yield strength decreases from 943 MPa to 389 MPa. At tensile temperature ranging from 500 ℃ to 700 ℃, the yield strength decreases significantly. During tensile testing at 500-700 ℃, the contribution of M2C-type carbide precipitation strengthening decreases by 3.67 MPa, the contribution of dislocation strengthening decreases by 11.78 MPa, the contribution of martensite lath boundary strengthening decreases by 51.39 MPa, and the contribution of Mo solid solution strengthening decreases by 267.29 MPa. It can be seen that the solid solution strengthening of Mo element is the main factor affecting the high-temperature strength of the 25Cr3Mo3NiNb steel. In the double-tempered 25Cr3Mo3NiNb steel, for every 1% mass fraction of Mo element in solid solution, the strength increments at tensile temperatures of 100, 500, 600 and 700 ℃ are 23.38, 140.94, 126.83 and 32.42 MPa, respectively. It can be seen that Mo element exhibits a good solid solution strengthening effect before 600 ℃, while the solid solution strengthening effect weakens at 700 ℃.

Key words: high-strength steel, tensile temperature, solid solution strengthening, yield strength, M2C carbide

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