金属热处理 ›› 2021, Vol. 46 ›› Issue (12): 294-297.DOI: 10.13251/j.issn.0254-6051.2021.12.049

• 失效分析 • 上一篇    

汽车前轴用40Cr钢锻件开裂失效分析

程源1, 胡芳忠2, 杨少朋2,3, 汪开忠2, 金国忠2, 陈世杰2, 王良林1   

  1. 1.安徽华菱汽车有限公司 车桥分公司, 安徽 马鞍山 243000;
    2.马鞍山钢铁股份有限公司 技术中心, 安徽 马鞍山 243000;
    3.钢铁研究总院 特殊钢研究所, 北京 100081
  • 收稿日期:2021-07-23 出版日期:2021-12-25 发布日期:2022-02-18
  • 通讯作者: 杨少朋,中级工程师,博士研究生,E-mail:1848554205@qq.com
  • 作者简介:程 源(1985—),男,中级工程师,本科,主要研究方向为汽车车桥产品开发,E-mail:chengyuan4698@163.com。
  • 基金资助:
    工信部工业强基项目(TC180A3Y1/分包号:14)

Cracking failure analysis of 40Cr steel forgings for automobile front axle

Cheng Yuan1, Hu Fangzhong2, Yang Shaopeng2, 3, Wang Kaizhong2, Jin Guozhong2, Chen Shijie2, Wang Lianglin1   

  1. 1. Cheqiao Branch, Anhui Hualing Automobile Co., Ltd., Ma'anshan Anhui 243000, China;
    2. Technology Center, Ma'anshan Iron and Steel Co., Ltd., Ma'anshan Anhui 243000, China;
    3. Research Institute of Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China
  • Received:2021-07-23 Online:2021-12-25 Published:2022-02-18

摘要: 利用化学成分、显微组织以及硬度分析等方法,对汽车前轴用40Cr钢锻件的开裂原因进行了分析。结果表明:裂纹位于锻件的R角处,为淬火裂纹;锻件R角处的元素偏析造成淬透性显著高于周围其它位置,锻造过程中产生了表面缺陷,使得淬火时马氏体相变产生的体积内应力超过了材料的强度,造成了淬火裂纹的产生;通过增大R角半径、控制原材料的成分偏析以及调整锻造工艺等措施,能够减小汽车前轴用40Cr钢锻件热处理后淬火开裂的风险。

关键词: 40Cr钢, 汽车前轴, 淬火裂纹, 元素偏析

Abstract: Cracking reason of 40Cr steel forgings used for automobile front axle was analyzed by means of chemical composition, microstructure and hardness analysis. The results show that the crack is a quenching crack occurred at the R angle of the forgings. The elemental segregation at the R angle of the forgings results in significantly higher hardenability than that of other locations around. Surface defects are produced in the forging process, so that the volume stress generated by martensitic transformation during quenching exceeds the strength of the material, resulting in the generation of quenching cracks. By increasing the R angle radius, controlling the chemical segregation of raw materials and adjusting the forging process, the risk of quenching cracking of 40Cr steel forgings for automobile front axle after heat treatment can be reduced.

Key words: 40Cr steel, automotive front axle, quenching crack, elemental segregation

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