Open AccessFatigue life extension of 42CrMo high-strength steel and its micro strengthening mechanism under laser shock peening
Author(s) -
Rujian Sun,
Weiqing Huang,
Ziwen Cao,
Zhigang Che,
Shikun Zou,
Junfeng Wu
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/892/1/012005
Subject(s) - peening , materials science , residual stress , shock (circulatory) , laser peening , misorientation , metallurgy , shot peening , grain boundary , indentation hardness , fatigue limit , composite material , microstructure , medicine
Laser shock peening is an advanced surface treatment technique in improving the fatigue properties of metallic components. In this study, the effects of different laser shock peening regions on the high cycle fatigue of 42CrMo high-strength steel were investigated. Surface deformation, residual stress, and microhardness were analyzed, and microstructural evolution including grain size, boundary distribution, and misorientation was examined. Results show that peening the specimen with both surfaces and sides resulted in a better fatigue life than only peening the surface. The compressive residual stress introduced in both the surfaces and sides provided a higher resistance for fatigue initiation. In addition, the increase of low angle grain boundary accounted for the micro strengthening mechanism for the fatigue life extension.