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The primary objective of this research is to meticulously examine how pulse magnetic field assisted deep cryogenic (MDC) treatment affects the transformation and stabilization of retained austenite in Cr4Mo4V bearing steel. This study aims to elucidate the underlying mechanisms by which the pulse magnetic field influences the microstructural changes in bearing steel, particularly focusing on the stabilization of retained austenite, which plays a crucial role in determining the mechanical properties and overall performance of the steel.
To achieve a comprehensive understanding of how retained austenite transformed under various treatment conditions, this study utilized several material characterization techniques, including X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and electron backscatter diffraction (EBSD). The use of EBSD analysis allows for a detailed comparison of variations in the dislocation density among samples processed under different conditions. For comparative analysis, the experimental set-up was divided into two distinct treatment processes: the conventional deep cryogenic (DC) treatment and the MDC treatment. Following these treatments, the samples were subjected to high-temperature tempering to evaluate the thermal stability of the retained austenite.
The XRD analysis revealed a reduction in the volume fraction of retained austenite from (23.8%±0.6)% to (21.5%±0.9)% following the DC process. A relatively smaller reduction to (22.5%±0.5)% was observed with the MDC process. These results, supported by VSM and EBSD analyses, highlight the capacity of the pulse magnetic field to partially inhibit the transformation of retained austenite. Further examination of the high-temperature stability of austenite in samples treated with DC and MDC revealed that MDC samples demonstrated improved retention, maintaining 7.1% of retained austenite after high-temperature tempering, compared to 4.9% in DC-treated samples. This indicates that the retained austenite in Cr4Mo4V bearing steel exhibits improved high-temperature stability following treatment with the MDC process. Furthermore, the dislocation density analysis revealed that the DC process led to a 9.8% increase in the dislocation density, whereas the MDC process moderated this increase to only 6.5%. This difference suggests the magnetic field's role in inhibiting dislocation diffusion, which in turn reduces martensite nucleation sites, thereby stabilizing retained austenite. The dislocation density change of the samples treated with DC and MDC after a high-temperature tempering validates this point. The dislocation density in DC-treated samples was approximately 1.23×1015 m-2, while it decreased to 1.13×1015 m-2 in MDC-treated samples. The dislocation density change reflects the extent of phase transformation.
This study provides a thorough analysis that clearly demonstrates the significant impact of applying a pulse magnetic field during deep cryogenic treatment on the microstructural evolution of Cr4Mo4V bearing steel. The magnetic field not only moderates the increase in the dislocation density but also enhances the mobility of dislocations. This contributes to the stabilization of retained austenite, which is crucial for improving the mechanical properties and performance of bearing steel. The findings of this research lay a solid foundation for optimizing heat treatment processes using the magnetic field assisted deep cryogenic treatment.
DU N Y, LIU H H, CAO Y F, et al. Formation mechanism of MC and M2C primary carbides in as-cast M50 bearing steel [J]. Materials Characterization, 2021, 174: 111011.
WANG F, QIAN D S, XIE L C, et al. Microstructure evolution and tempering transformation kinetics in a secondary hardened M50 steel subjected to cold ring rolling [J]. ISIJ International, 2021, 61(1): 361-371.
NAM J M, TERAI T, KAKESHITA T. Effects ofparticle and grain sizes on martensitic transformation in an Fe-30.5at. %Ni alloy [J]. Journal of Alloys and Compounds, 2013, 577: S348-S352.
ANTONY A, SCHMERL N M, SOKOLOVA A, et al. Quantification of the dislocation density, size, and volume fraction of precipitates in deep cryogenically treated martensitic steels [J]. Metals, 2020, 10(11): 1561.
QIAO X, HAN L Z, ZHANG W M, et al. Thermal stability of retained austenite in high-carbon steels during cryogenic and tempering treatments [J]. ISIJ International, 2016, 56(1): 140-147.
DAS D, DUTTA A K, RAY K K. Optimization of the duration of cryogenic processing to maximize wear resistance of AISI D2 steel [J]. Cryogenics, 2009, 49(5): 176-184.
NAWAZ B, LONG X Y, YANG Z N, et al. Effect of magnetic field on microstructure and mechanical properties of austempered 70Si3MnCr steel [J]. Materials Science and Engineering: A, 2019, 759: 11-18.
WANG F, QIAN D S, HUA L, et al. Effect of high magnetic field on the microstructure evolution and mechanical properties of M50 bearing steel during tempering [J]. Materials Science and Engineering: A, 2020, 771: 138623.
KAKESHITA T, SABURI T, KINDO K, et al. Effect of magnetic field and hydrostatic pressure on martensitic transformation and its kinetics [J]. Japanese Journal of Applied Physics, 1997, 36(12A): 7083-7094.
ZHAO L, VAN DIJK N H, BRVCK E, et al. Magnetic and X-ray diffraction measurements for the determination of retained austenite in TRIP steels [J]. Materials Science and Engineering: A, 2001, 313(1-2): 145-152.
ZHOU Y C, CHAO Y S. Studies on Mössbauer spectroscopy of nanocrystallization of amorphous Fe78Si9B13 alloy at low temperature by low frequency pulse magnetic field [J]. Rare Metal Materials and Engineering, 2009, 38(5): 847-850. (in Chinese)
MA L P, ZHAO W X, LIANG Z Q, et al. An investigation on the mechanical property changing mechanism of high speed steel by pulsed magnetic treatment [J]. Materials Science and Engineering: A, 2014, 609: 16-25.
QIAN C K, LI K J, RUI S S, et al. Magnetic induced re-dissolution and microstructure modifications on mechanical properties of Cr4Mo4V steel subjected to pulsed magnetic treatment [J]. Journal of Alloys and Compounds, 2021, 881: 160471.
WINKELMANN A. Dynamical effects of anisotropic inelastic scattering in electron backscatter diffraction [J]. Ultramicroscopy, 2008, 108(12): 1546-1550.
KANG C P, LIU F B, JIANG Z H, et al. Effect of cryogenic treatment on microstructure evolution and mechanical properties of high nitrogen plastic die steel [J]. Journal of Materials Research and Technology, 2021, 15: 5128-5140.
AKHBARIZADEH A, AMINI K, JAVADPOUR S. Effect of simultaneous magnetic field and deep cryogenic heat treatment on the microstructure of 1.2080 tool steel [J]. Materials & Design, 2012, 35: 484-490.
WANG J, TAO Q, FAN J T, et al. Enhanced mechanical properties of a high-carbon martensite steel processed by heavy warm rolling and tempering [J]. Materials Science and Engineering: A, 2023, 872: 144958.
HE T T, WANG L, HU F, et al. Stability of retained austenite and work hardening behavior in ultra-fine medium carbon bainitic steel [J]. Journal of Materials Research and Technology, 2023, 22: 2690-2703.
KOHNO Y, KONISHI H, SHIBATA K, et al. Effects of reheating after solution treatment and magnetic fields on α'martensite formation in SUS304L steel during isothermal holding at cryogenic temperature [J]. Materials Science and Engineering: A, 1999, 273-275: 333-336.
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