金属热处理 ›› 2021, Vol. 46 ›› Issue (1): 70-74.DOI: 10.13251/j.issn.0254-6051.2021.01.013

• 工艺研究 • 上一篇    下一篇

淬火温度对2200 MPa级超高强度钢力学性能与微观组织的影响

张鹏杰, 王春旭, 厉勇, 韩顺, 刘少尊   

  1. 钢铁研究总院 特殊钢研究所,北京 100081
  • 收稿日期:2020-06-20 出版日期:2021-01-25 发布日期:2021-01-26
  • 通讯作者: 王春旭,教授,博士,E-mail:wangchunxu@nercast.com
  • 作者简介:张鹏杰(1994—),男,硕士,主要研究方向为超高强度钢,E-mail:zhpengjie94@163.com。
  • 基金资助:
    国家自然科学基金(51675363)

Effect of quenching temperature on mechanical properties and microstructure of 2200 MPa ultra-high strength steel

Zhang Pengjie, Wang Chunxu, Li Yong, Han Shun, Liu Shaozun   

  1. Institute of Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China
  • Received:2020-06-20 Online:2021-01-25 Published:2021-01-26

摘要: 采用力学性能测试、光学显微镜(OM)、透射电镜(TEM)、X射线衍射(XRD)等材料分析方法研究了淬火温度对2200 MPa级超高强度钢的力学性能及微观组织的影响。结果表明,试验钢最佳淬火温度为1025 ℃,再经后续热处理能获得最佳的强韧性匹配,此时抗拉强度为2244 MPa,屈服强度为1836 MPa,U型缺口冲击吸收能量为59 J,断裂韧性为57.7 MPa·m1/2。淬火温度较低时,出现粗大一次碳化物富Mo型M6C碳化物,严重影响强度和韧性。随着淬火温度升高,一次碳化物逐渐减少,直至1000 ℃完全消失,当淬火温度高于1025 ℃时晶粒显著粗化,晶粒尺寸成为主要的负面影响因素。

关键词: 2200 MPa级超高强度钢, 淬火, 力学性能, 微观组织, M6C

Abstract: Effect of quenching temperature on the mechanical properties and microstructure of 2200 MPa ultra-high strength steel was studied by means of mechanical properties test,optical microscope (OM),transmission electron microscope (TEM),X-ray diffraction (XRD) and other analysis methods.The results show that the optimal quenching temperature of the tested steel is 1025 ℃,so the subsequent heat treatment can obtain the best strength and toughness match:the tensile strength is 2244 MPa,the yield strength is 1836 MPa,the U-notch impact absorbed energy is 59 J,and the fracture toughness is 57.7 MPa·m1/2.When the quenching temperature is low,coarse primary carbides appear in Mo-rich M6C carbides,which seriously affect strength and toughness.As the quenching temperature increases,the primary carbide gradually decreases until it completely disappears at 1000 ℃.When the quenching temperature is higher than 1025 ℃,the grains are significantly coarsened,and the grain size becomes the main negative influencing factor.

Key words: 2200 MPa ultra-high strength steel, quenching, mechanical properties, microstructure, M6C

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