金属热处理 ›› 2020, Vol. 45 ›› Issue (8): 7-11.DOI: 10.13251/j.issn.0254-6051.2020.08.002

• 组织与性能 • 上一篇    下一篇

夹杂物对工程机械用钢Q345FCA疲劳寿命的影响

李明阳1, 王福明1, 李明2, 弓硕1   

  1. 1.北京科技大学 冶金与生态工程学院, 北京 100083;
    2.南京钢铁股份有限公司, 江苏 南京 210035
  • 收稿日期:2020-01-20 出版日期:2020-08-25 发布日期:2020-09-07
  • 通讯作者: 王福明,教授,博士,E-mail:wangfuming@metall.ustb.edu.cn
  • 作者简介:李明阳(1993—),男,硕士,主要研究方向为钢铁材料的合金化、相变及组织与性能,E-mail:18810610463@163.com

Effect of inclusions on fatigue life of engineering machinery structural steel Q345FCA

Li Mingyang1, Wang Fuming1, Li Ming2, Gong Shuo1   

  1. 1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    2. Nanjing Iron & Steel Co. , Ltd. , Nanjing Jiangsu 210035, China
  • Received:2020-01-20 Online:2020-08-25 Published:2020-09-07

摘要: 采用QBWP-6000J型简支梁旋转弯曲疲劳试验机测定了高疲劳寿命工程机械用钢Q345FCA的疲劳寿命;采用扫描电镜(SEM)对疲劳断口形貌进行了观察,并用附带的能谱仪(EDS)寻找断口上的夹杂物;借助夹杂物自动分析系统对钢中的夹杂物进行了分析。通过对试验数据的分析,计算得出了Q345FCA钢和Q345钢夹杂物的表面临界尺寸、次表面临界尺寸和内部临界尺寸。结果表明,Q345FCA钢的疲劳极限为273 MPa,Q345钢的疲劳极限为266 MPa。Q345FCA钢和Q345钢中夹杂物尺寸均小于临界夹杂物尺寸,且断口形貌显示所有疲劳断裂均不是由夹杂物所引起,夹杂物不是疲劳源。

关键词: 工程机械用钢Q345FCA, 疲劳寿命, 夹杂物, 临界尺寸

Abstract: Fatigue life of the high fatigue life Q345FCA steel for engineering machinery was determined by using QBWP-6000J rotary bending fatigue testing machine for simply supported beams. The fatigue fracture morphology was observed by scanning electron microscope (SEM) and the inclusions on fracture surface were searched by energy dispersive spectrometer (EDS). The inclusions were analyzed by inclusion automatic analysis system, and the critical size of inclusions was calculated through experimental data analysis. The results show that the fatigue strength of Q345FCA steel and Q345 steels is 273 MPa and 266 MPa, respectively. The size of the inclusions in the Q345FCA steel and Q345 steel is all small, which is smaller than the critical size of the inclusions, and the fracture morphologies show that all the fatigue fractures are not caused by inclusions, which are not the source of fatigue.

Key words: engineering machinery structural steel Q345FCA, fatigue life, inclusions, critical size

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