Microstructure Evolution Mechanism of AISI 1045 Steel Under High Speed Deformation

AISI 1045 steel has the characteristics of high strain rate, large strain, and sharp rise in temperature during high-speed deformation process, resulting in a concentrated deformation band and fine structure. In this work, the microstructure of submicron-sized grains in AISI 1045 steel material formed under 106 s-1 during a high speed cutting process was examined. To reveal the dynamic evolution mechanism of the AISI 1045 microstructure, the continuous dynamic recrystallization theory was introduced. The results show a high dislocation density which favor the formation of small angle grain boundaries during the high speed cutting process. Kinetics calculations that use continuous dynamic recrystallization mechanisms prove that the recrystallization size is constant when the strain rate increases from 103 s-1 to 106 s-1, and the transition time is reduced from 6×10-5 s to 4×10-8 s. The recrystallization grains were gradually formed during the deformation of the material, not generated after the deformation.

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This research was supported by the Project of the National Natural Science Foundation of China (Grant No. U1960101, No. 51874272 and No. 52111540265), Sichuan Science and Technology Program (No. 2021YJ0548), Chongqing Municipal Natural Science Foundation (cstc2020jcyj-msxmX0060), Panzhihua Science and Technology Project (Grant No. 2020CY-G-15), the Open Project of the State Key Laboratory of Advanced Metallurgy (KF20-03), Key Laboratory of Comprehensive Utilization of Vanadium and Titanium Resources in Sichuan Province (2019FTSZ06), the PhD Fund of Panzhihua University, and Funded by the State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization; Open Foundation of State Key Laboratory of Mineral Processing (No. BGRIMM-KJSKL-2022-23) and Open Foundation of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization (No. CNMRCUKF2205), Scientific Research Key Project of Yibin University (412-0219020202); The Education and Teaching Reform Project of Tangshan Normal University of China (Grant No. 2019JG020); Sichuan Vanadium and Titanium Industry Development Research Center (2020VTCY-Y-02); Sichuan Vanadium Titanium Material Engineering Technology Research Center (2022FTGC06).