金属热处理 ›› 2023, Vol. 48 ›› Issue (5): 294-297.DOI: 10.13251/j.issn.0254-6051.2023.05.048

• 失效分析 • 上一篇    下一篇

35CrMo钢高强螺栓断裂失效分析

王朴1,2, 童辉3   

  1. 1.上海工程技术大学 高等职业技术学院, 上海 200437;
    2.上海市高级技工学校, 上海 200437;
    3.上海汽车集团有限公司商用车技术中心, 上海 200082
  • 收稿日期:2022-10-24 修回日期:2023-03-21 出版日期:2023-05-25 发布日期:2023-06-21
  • 作者简介:王 朴(1991—),女,讲师,硕士,主要研究方向为材料科学、材料加工,E-mail: wangpu1211@163.com

Fracture failure analysis of 35CrMo steel high strength bolt

Wang Pu1,2, Tong Hui3   

  1. 1. High Vocational and Technical College, Shanghai University of Engineering Science, Shanghai 200437, China;
    2. Shanghai Technician School, Shanghai 200437, China;
    3. Commercial Vehicle Technology Center of SAIC Motor Corporation, Shanghai 200082, China
  • Received:2022-10-24 Revised:2023-03-21 Online:2023-05-25 Published:2023-06-21

摘要: 某重型牵引车鞍座35CrMo钢高强度固定螺栓打紧后放置2天时发生断裂。通过断口分析、金相检测、成分分析、硬度分析和力学测试对断裂螺栓和同批次未使用螺栓样件进行研究。结果表明,该断裂螺栓在酸洗电镀的过程中,引入的有害氢未能得到及时、有效地去除,从而导致螺栓根部在预紧力作用下,氢向应力集中处聚集,出现了螺栓氢致延迟断裂的现象。

关键词: 35CrMo钢, 高强螺栓, 氢致开裂

Abstract: 35CrMo steel high strength bolt of a heavy tractor broke after being tightened and placed for 2 days. The fractured bolt and the unused bolt of the same batch were studied by fracture analysis, metallographic examination, composition analysis, hardness analysis and mechanical testing. The results show that the harmful hydrogen introduced during the pickling and electroplating process is not effectively and timely removed, which results in the hydrogen accumulating towards the stress concentrated root of the bolt under the preload for tightening, so that the hydrogen induced delayed fracture phenomenon for the bolt occurs.

Key words: 35CrMo steel, high strength bolt, hydrogen induced fracture

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