金属热处理 ›› 2024, Vol. 49 ›› Issue (2): 135-141.DOI: 10.13251/j.issn.0254-6051.2024.02.020

• 工艺研究 • 上一篇    下一篇

调质工艺对Cr-Ni-Mo-V超高强韧钢组织和力学性能的影响

周琮1, 陈献刚2, 曹铁山1, 赵杰1   

  1. 1.大连理工大学 材料科学与工程学院, 辽宁 大连 116024;
    2.北方重工业集团有限公司, 内蒙古 包头 014033
  • 收稿日期:2023-08-23 修回日期:2023-12-15 出版日期:2024-03-27 发布日期:2024-03-27
  • 通讯作者: 赵 杰,教授,E-mail:jiezhao@dlut.edu.cn
  • 作者简介:周 琮(1998—),男,硕士研究生,主要研究方向为超高强韧钢性能,E-mail:zc17864274727@163.com。

Effect of quenching and tempering process on microstructure and mechanical properties of a Cr-Ni-Mo-V ultra-high strength and toughness steel

Zhou Cong1, Chen Xiangang2, Cao Tieshan1, Zhao Jie1   

  1. 1. School of Materials Science and Engineering, Dalian University of Technology, Dalian Liaoning 116024, China;
    2. Northern Heavy Industry Group Co., Ltd., Baotou Inner Mongolia 014033, China
  • Received:2023-08-23 Revised:2023-12-15 Online:2024-03-27 Published:2024-03-27

摘要: 利用扫描电镜、金相显微镜、冲击试验机结合维氏硬度计研究了780、830和880 ℃淬火+500~580 ℃高温回火处理对Cr-Ni-Mo-V超高强韧钢显微组织和力学性能的影响。结果表明,随回火温度的升高,尺寸较大碳化物会发生溶解转变,合金碳化物由基体中不断弥散析出。硬度和冲击性能均随回火温度升高呈现先增大后降低的趋势,与碳化物弥散析出形貌和残留奥氏体分解转变有关;3种温度淬火试验钢均在540 ℃回火时出现二次硬化峰值,最高值分别为488、517、532 HV20,在540~560 ℃回火出现最大冲击吸收能量,分别为49.7、58.5、51.0 J。为充分保证钢的强韧性,最佳热处理工艺为830 ℃亚温临界淬火+560 ℃回火。

关键词: Cr-Ni-Mo-V超高强韧钢, 调质处理, 二次硬化, 冲击性能

Abstract: Effects of quenching at 780, 830, and 880 ℃ and high-temperature tempering at 500-580 ℃ on the microstructure and mechanical properties of a Cr-Ni-Mo-V ultra-high strength and toughness steel were studied by means of scanning electron microscope, metallographic microscope, impact testing machine, and Vickers hardness tester. The results show that with the increase of tempering temperature, the carbides with larger size undergo dissolution transformation, while the alloy carbides continuously precipitate out dispersively from the the matrix. Both the hardness and impact properties show a trend of first increasing and then decreasing with the increase of tempering temperature, which are related to the dispersion morphologies of the precipitated carbides and the decomposition of retained austenite. The tested steels quenched at three different temperatures all show secondary hardening peaks when tempering at 540 ℃, with the highest hardness values being 488, 517, and 532 HV20, respectively. The maximum impact absorbed energy is obtained when tempering at 540-560 ℃, with values of 49.7, 58.5, and 51.0 J, respectively. In order to fully ensure the strength and toughness of the steel, the optimal heat treatment process is subcritical quenching at 830 ℃ and then tempering at 560 ℃.

Key words: Cr-Ni-Mo-V ultra-high strength and toughness steel, quenching and tempering treatment, secondary hardening, impact property

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