金属热处理 ›› 2023, Vol. 48 ›› Issue (1): 257-260.DOI: 10.13251/j.issn.0254-6051.2023.01.045

• 失效分析 • 上一篇    下一篇

42CrMo钢六角头螺栓热镀锌裂纹分析

赵全育1, 梁嘉俊2, 陈旭鹏2, 童波1, 夏国华1, 严琴1, 丁志敏1   

  1. 1.飞沃新能源科技股份有限公司, 湖南 常德 415701;
    2.中南大学 材料科学与工程学院, 湖南 长沙 410083
  • 收稿日期:2022-08-17 修回日期:2022-11-14 出版日期:2023-01-25 发布日期:2023-02-03
  • 通讯作者: 梁嘉俊,硕士研究生,主要研究方向为先进钢铁材料,E-mail:1270080863@qq.com
  • 作者简介:赵全育(1983—),男,工程师,主要研究方向为风电紧固件材料,E-mail:fwyoujun2020@126.com。

Cracking analysis of 42CrMo steel hexagon head bolt by hot dip galvanizing

Zhao Quanyu1, Liang Jiajun2, Chen Xupeng2, Tong Bo1, Xia Guohua1, Yan Qin1, Ding Zhimin1   

  1. 1. Finework New Energy Technology Co., Ltd., Changde Hunan 415701, China;
    2. School of Materials Science and Engineering, Central South University, Changsha Hunan 410083, China
  • Received:2022-08-17 Revised:2022-11-14 Online:2023-01-25 Published:2023-02-03

摘要: 42CrMo钢六角头螺栓在热镀锌工艺完成后的磁粉探伤时发现部分螺栓的圆角处存在裂纹。采用光学显微镜、扫描电镜和能谱仪等对螺栓进行了断口、显微组织和成分分析。结果表明,开裂螺栓经破断后的断口符合氢脆断口特征,断口附近氢元素的质量分数偏高,达4×10-6。裂纹形貌特征和氢脆裂纹特征吻合,裂纹两侧组织为正常的调质组织且裂纹内还发现有锌液残余,可以排除裂纹是由于组织异常或在淬火时产生的。因此,可以推断42CrMo钢六角头螺栓开裂类型为氢致开裂,氢致开裂发生在热镀锌过程中。

关键词: 42CrMo钢, 六角头螺栓, 热镀锌, 氢致开裂

Abstract: Cracks were found at the round corners of the 42CrMo steel hexagon head bolts after hot dip galvanizing through magnetic particle inspection. Fracture, microstructure and composition analysis of the cracked bolt were carried out by means of optical microscope, SEM and EDS. The results show that the fracture of the cracked bolts conforms to the characteristics of hydrogen embrittlement, and the mass fraction of hydrogen near the fracture is as high as 4×10-6.The crack characteristics are consistent with the hydrogen embrittlement crack characteristics. The microstructure on both sides of the crack is normal quenched and tempered structure and zinc residue is found in the crack, which can exclude that the crack is caused by abnormal tissue or quenching. Therefore, it can be reasonably inferred that the crack of 42CrMo steel hexagonal bolt is hydrogen-induced cracking, which occurs in the process of hot dip galvanizing.

Key words: 42CrMo steel, hexagon bolts, hot dip galvanizing, hydrogen induced cracking

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