金属热处理 ›› 2021, Vol. 46 ›› Issue (2): 14-19.DOI: 10.13251/j.issn.0254-6051.2021.02.003

• 材料研究 • 上一篇    下一篇

稀土元素La对300M钢疲劳性能的影响

刘跃1, 韩顺1, 厉勇1, 王春旭1, 高远航1, 王瑞2, 李建新2   

  1. 1.钢铁研究总院 特殊钢研究所, 北京 100081;
    2.抚顺特殊钢股份有限公司 技术中心, 辽宁 抚顺 113001
  • 收稿日期:2020-07-15 出版日期:2021-02-25 发布日期:2021-05-08
  • 通讯作者: 韩顺,工程师,硕士,E-mail:hanshunfa@126.com
  • 作者简介:刘跃(1996—),男,硕士研究生,主要研究方向为超高强度钢,E-mail:Junexplore@163.com。
  • 基金资助:
    国家重点研发计划(2016YFB0300104)

Effect of rare earth lanthanum on fatigue property of 300M steel

Liu Yue1, Han Shun1, Li Yong1, Wang Chunxu1, Gao Yuanhang1, Wang Rui2, Li Jianxin2   

  1. 1. Institute of Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China;
    2. Technology Center, Fushun Special Steel Co., Ltd., Fushun Liaoning 113001, China
  • Received:2020-07-15 Online:2021-02-25 Published:2021-05-08

摘要: 采用力学性能测试、疲劳断口形貌及裂纹源非金属夹杂物扫描电镜分析等方法,研究了稀土元素La对300M钢常规力学及高周疲劳性能的影响,以及稀土La对300M钢非金属夹杂物形态及尺寸的改性作用。结果表明:添加0.006%(质量分数)的稀土La对300M钢的常规力学性能影响较小,却显著提高300M钢的高周疲劳性能;300M钢加入稀土La后,其疲劳极限σ-1由867 MPa提高至940 MPa;添加稀土La改性后的钢中夹杂物尺寸变大,并转变为含S、O的稀土夹杂物,其硬度、弹性模量、膨胀系数与钢基体更接近,有效减小了夹杂处的应力集中,有利于提高钢的高周疲劳性能。

关键词: 300M钢, 稀土La, 疲劳裂纹源, 非金属夹杂物

Abstract: Effects of rare earth element La on the conventional mechanical properties and high cycle fatigue property of 300M steel and its modification effect on the morphology and size of nonmetallic inclusions in the steel were studied by mechanical property test, SEM analysis of fatigue fracture morphology and non-metallic inclusions at crack sources. The results show that, 0.006wt% lanthanum has little effect on the conventional mechanical properties, but significantly improves the high cycle fatigue property of the 300M steel, leading to that the high cycle fatigue limit σ-1 of the 300M steel increases from 867 MPa to 940 MPa. The inclusions in the La-modified steel become larger in size, and change to rare earth inclusions containing S and O. The hardness, elastic modulus and expansion coefficient of the inclusions are closer to that of the steel matrix, which can effectively reduce the stress concentration around the inclusions and improve the high cycle fatigue properties of the steel.

Key words: 300M steel, lanthanum, fatigue crack source, non-metallic inclusion

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