金属热处理 ›› 2023, Vol. 48 ›› Issue (10): 302-306.DOI: 10.13251/j.issn.0254-6051.2023.10.047

• 失效分析 • 上一篇    下一篇

IN718合金螺栓断裂分析

张海峰   

  1. 中国船舶重工集团公司第七二五研究所(洛阳船舶材料研究所), 河南 洛阳 471023
  • 收稿日期:2023-05-10 修回日期:2023-08-15 出版日期:2023-10-25 发布日期:2023-12-07
  • 作者简介:张海峰(1965—),男,研究员,硕士,主要研究方向为失效分析及材料评价,E-mail:ly7256@163.com

Fracture analysis on IN718 alloy bolt

Zhang Haifeng   

  1. Luoyang Ship Material Research Institute, Luoyang Henan 471023, China
  • Received:2023-05-10 Revised:2023-08-15 Online:2023-10-25 Published:2023-12-07

摘要: 柴油机排气管IN718合金螺栓使用过程中发生早期断裂,通过化学成分检测、拉伸试验、金相分析、断口形貌观察、析出相透射电镜观察等手段从螺栓材料组织结构、制造工艺两个方面探究了断裂失效的原因。结果表明,螺栓断裂的主要原因为滚压螺纹后表面处于高能状态,螺纹根部在随后的时效处理时析出大量纳米相,螺牙根部表层脆化所致。

关键词: 螺栓, 纳米相, 脆化, 断裂

Abstract: Early breaking failure occurred during the use of diesel engine exhaust bolts made of IN718 alloy. The causes of the bolt fracture were investigated by means of chemical composition testing, tensile testing, metallographic analysis, observation of fracture morphology, and transmission electron microscope observation of precipitates from two aspects of material microstructure and manufacturing process. The results show that the main reason for the bolt fracture is that the surface of the rolled thread is in a high-energy state, and a large amount of nano phases precipitate at the root of the thread during subsequent aging treatment, resulting in embrittlement of the surface layer at the root of the thread.

Key words: bolt, nanophase, embrittlement, fracture

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