金属热处理 ›› 2024, Vol. 49 ›› Issue (4): 257-263.DOI: 10.13251/j.issn.0254-6051.2024.04.041

• 表面工程 • 上一篇    下一篇

高能喷丸强化工业纯铁的疲劳裂纹扩展性能

刘荣伟, 黄志国, 刘翔宇, 孙杨锋, 魏艳东, 崔喜贺, 侯和龙, 胥林东   

  1. 河北石油职业技术大学 工业技术中心, 河北 承德 067000
  • 收稿日期:2023-11-06 修回日期:2024-03-11 出版日期:2024-04-25 发布日期:2024-05-27
  • 通讯作者: 黄志国,副教授,E-mail:27841227@qq.com
  • 作者简介:刘荣伟(1992—),男,讲师,硕士,主要研究方向为材料断裂韧性和金属可靠性,E-mail:cdpc_lrw2018@163.com。
  • 基金资助:
    河北省自然科学基金(B2021411001);河北省高等学校科学技术研究项目(ZC2023188);承德市应用技术研究与开发暨可持续发展议程创新示范区专项科技计划项目(202305B018)

Fatigue crack propagation properties of industrial pure iron intensified by high energy shot peening

Liu Rongwei, Huang Zhiguo, Liu Xiangyu, Sun Yangfeng, Wei Yandong, Cui Xihe, Hou Helong, Xu Lindong   

  1. Industrial Technology Center, Hebei Petroleum University of Technology, Chengde Hebei 067000, China
  • Received:2023-11-06 Revised:2024-03-11 Online:2024-04-25 Published:2024-05-27

摘要: 采用高能喷丸在工业纯铁表面形成了自纳米化层,通过疲劳裂纹扩展试验对母材和高能喷丸试样进行对比分析,研究了高能喷丸对疲劳裂纹扩展速率、显微组织、显微硬度和疲劳断口形貌的影响规律。结果表明,高能喷丸对疲劳裂纹萌生及应力强度因子低于50 MPa·m1/2的疲劳裂纹扩展有显著的抑制作用,但对应力强度因子高于50 MPa·m1/2的疲劳裂纹扩展影响不明显。高能喷丸后试样表层组织出现晶粒严重破碎、挤压,表面硬度较母材提升约40%,但随深度的增加硬度迅速降低。高能喷丸的最大影响深度达到3.88×10-4 mm,试样由表及里可划分为表层破坏区域—纳米层—晶粒严重变形区—晶粒变形区—未受影响区,不同区域之间无明显界限。

关键词: 工业纯铁DT4C, 高能喷丸, 疲劳裂纹扩展, 显微组织, 疲劳断口

Abstract: High-energy shot peening was adopted to form self-nanocrystallization layer on the surface of industrial pure iron, and its effects on fatigue crack propagation rate, microstructure, microhardness and fatigue fracture morphology of the base metal were comparatively analyzed by fatigue crack propagation test. The results show that high-energy shot peening has a significant inhibitory effect on initiation and propagation of the fatigue crack when the stress intensity factor is lower than 50 MPa·m1/2, but it is not obvious for that higher than 50 MPa·m1/2. After high-energy shot peening, the grains on surface structure of the specimen are seriously extruded and fragmented, and the surface hardness is about 40% higher than that of the base metal, while the hardness decreases rapidly with the increase of the depth from surface. The maximum effect depth of high-energy shot peening reaches 3.88×10-4 mm. From the surface to the inside of the shot peening specimen, it can be divided into surface damage zone, nano layer, severe grain deformation zone, grain deformation zone and unaffected zone, and there is no obvious boundary between different zones.

Key words: industrial pure iron DT4C, high-energy shot peening, fatigue crack propagation, microstructure, fatigue fracture

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