金属热处理 ›› 2020, Vol. 45 ›› Issue (6): 201-205.DOI: 10.13251/j.issn.0254-6051.2020.06.042

• 材料研究 • 上一篇    下一篇

Si、Mn含量对1000 MPa级工程机械用钢组织和性能的影响

李有新1, 娄振洋1, 李小辉2   

  1. 1. 青海高等职业技术学院 机电工程系, 青海 海东 810799;
    2. 青海大学 机械工程学院, 青海 西宁 810016
  • 收稿日期:2019-12-19 出版日期:2020-06-25 发布日期:2020-09-02
  • 作者简介:李有新(1981—),男 ,高级工程师,主要研究方向为机械工程材料研究应用,Email:xinwhut@qq.com

Effects of Si, Mn content on microstructure and properties of steel for 1000 MPa grade construction machinery

Li Youxin 1, Lou Zhenyang 1, Li Xiaohui2   

  1. 1. Department of Mechanical and Electrical Engineering, Qinghai Higher Vocational and Technical Institute,Haidong Qinghai 810799, China;
    2. College of Mechanical Engineering, Qinghai University, Xining Qinghai 810016, China
  • Received:2019-12-19 Online:2020-06-25 Published:2020-09-02

摘要: 采用光学显微镜、扫描电镜和拉伸试验机等手段,研究了Si、Mn含量对电渣重熔工程机械用钢组织和性能的影响。结果表明,Mn含量适量增加虽然会促进晶粒长大,但是由于组织遗传效应明显高于Mn含量变化造成的晶粒度变化故晶粒尺寸仍然较小;而增加Si对原奥氏体晶粒影响较小;增加Mn并未对调质态工程机械用钢中的碳化物析出造成明显影响,增加Si的试样的碳化物虽然仍以颗粒状为主、并含有少量短棒状碳化物,但是碳化物数量明显较少、尺寸更加细小;增加Mn后,工程机械用钢的抗拉强度、规定塑性延伸强度和布氏硬度有所提高,而断后伸长率、断面收缩率和-40 ℃冲击吸收能量都有不同程度减小;增加Si后,工程机械用钢的抗拉强度、屈服强度和布氏硬度有所减小,而断后伸长率、断面收缩率和-40 ℃冲击吸收能量明显提升,但强度和布氏硬度都不满足工程机械用钢的使用规范要求;试验用1000 MPa级工程机械用钢适宜的Si和Mn含量分别为0.35wt%和1.12wt%。

关键词: 1000 MPa级工程机械用钢, Si和Mn含量, 调质处理, 显微组织, 性能

Abstract: Effects of Si and Mn content on microstructure and properties of steel for construction machinery were studied by means of optical microscope, scanning electron microscope and tensile testing machine. The results show that although the increase of Mn content promoted the grain growth, but the grain size is still low because the structure genetic effect is significantly higher than that caused by the change of Mn content, while the increase of Si content has little effect on the primary austenite grains. The increase of Mn content has no obvious effect on the precipitation of carbides in the quenched and tempered steel for construction machinery. Although the carbides in the specimens with increased Si content are still mainly granular, and has also a small amount of short rod carbides, the number of carbides is obviously less and the size is smaller. With the increase of Mn content, the tensile strength, yield strength and Brinell hardness of steel for construction machinery are improved, while the elongation, section shrinkage and impact absorbed energy at -40 ℃ are reduced to varying degrees. After adding Si content, the tensile strength, yield strength and Brinell hardness of steel for construction machinery are decreased, while the elongation, section shrinkage and impact absorbed energy at -40 ℃ are increased significantly, but the strength and Brinell hardness do not meet the standard requirements of steel for construction machinery; the appropriate Si and Mn content of steel for 1000 MPa grade construction machinery steel for test are 0.35 wt% and 1.12 wt%, respectively.

Key words: steel for 1000 MPa grade construction machinery, Si and Mn content, quenching and tempering, microstructure, properties

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