Evaluation of the Low‐Cycle Fatigue Life of Thin Dual‐Phase Steel Sheets for Automobiles Using Miniature Specimens. Issue 11 (2nd September 2019)

• Record Type: Journal Article
• Authors: Ma, Zhen-Hua; Zhang, Bin; Song, Zhu-Man; Liu, Hua-Sai; Zhang, Guang-Ping
• Is Part Of: Steel research international. Volume 90:Issue 11(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-09-02
• Subjects: cantilever beam bending -- dual-phase steels -- fatigue lives -- low-cycle fatigue -- miniature specimens; Steel -- Periodicals; Steel -- Metallurgy -- Periodicals; 669.142
• DOI: 10.1002/srin.201900186
• Languages: English
• ISSNs: 1611-3683

Abstract

Abstract : Using miniature 95 μm‐thick cantilever beam specimens, the fatigue life of a thin dual‐phase steel sheet is evaluated under deflection‐controlled repeatedly bending fatigue (RBF) loading and compared with that of 2 mm‐thick sheet specimens under strain‐controlled uniaxial tension‐compression fatigue (TCF) loading. The results indicate that the fatigue lives of the two types of specimens subjected to the respective two sorts of fatigue testing methods are almost identical in the low‐cycle fatigue (LCF) regime, whereas the fatigue life of the 95 μm‐thick foil specimens is much lower than that of the 2 mm‐thick sheet specimens in the high‐cycle fatigue regime. The fatigue performance and fracture mechanism under the two types of fatigue loadings are discussed and the application of this method using miniature cantilever beam specimens under RBF loading is further explored. The finding provides a potential way to obtain credible LCF data for vehicle steel sheets using miniature cantilever beam foils under RBF loading instead of TCF loading which becomes more difficult for the very thin steel sheets with a thickness less than 2 mm. Abstract : The low‐cycle fatigue (LCF) life of miniature 95 μm‐thick beam specimens under deflection‐controlled repeatedly bending fatigue loading is almost identical to that of 2 mm‐thick sheet specimens under strain‐controlled uniaxial tension‐compression loading. The finding provides a potential way to obtain credible LCF data for vehicle steel sheets using miniature beam foils under repeatedly bending loading instead of tension‐compression fatigue loading.