Effect of Annealing Process on Microstructures and Mechanical Properties of Cold-Rolled Martensitic Steels for Automotive Structural Parts

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Abstract:

Recently, light-weight and energy-saving requirements for the automobile industry are extremely important in order to protect the environment by a reduction of the emission of CO2. Hence, high-strength steel (AHSS), even ultrahigh strength steels with tensile strength larger than 1GPa is used. Among AHSS, cold-rolled martensitic steels have attracted much attention due to their superior strength to improve crashworthiness. In this research, the influence of different annealing treatments, especially the auto-tempering, on the phase transformation further affecting the mechanical properties and microstructure was investigated. The result shows that the level of auto-tempering and strength in martensitic steel is dominated by the quenching/auto-tempering temperature. Furthermore, the auto-tempering carbides should be cementite which is fine enough to improve yield strength. The suitable chemical composition combined with auto-tempering method has been implemented to develop cold-rolled martensitic steels with a tensile strength of exceeding 1300MPa. These developed martensitic steels can meet the requirements of bumper reinforcement which has applied in a variety of automobiles.

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Materials Science Forum (Volume 1174)

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63-68

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January 2026

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© 2026 Trans Tech Publications Ltd. All Rights Reserved

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[1] Information on https://ahssinsights.org/about/rationale/steel-e-motive/

Google Scholar

[2] M. Gao, K He, L Li, Q Wang, C. Liu, A Review on Energy Consumption, Energy Efficiency and Energy Saving of Metal Forming Processes from Different Hierarchies, Processes 7 (2019) 357-381.

DOI: 10.3390/pr7060357

Google Scholar

[3] B. Hutchinson, D. Lindell, M. Barnett, Yielding Behaviour of Martensite in Steel, ISIJ international 55 (2015) 1114-1122.

DOI: 10.2355/isijinternational.55.1114

Google Scholar

[4] X.T. Deng, T.L. Fu, Z.D. Wang, R.S.K. Misra, G.D. Wang, Epsilon Carbide Precipitation and Wear Behaviour of Low Alloy Wear Resistant Steels, Mater. Sci. Technol. 32 (2016) 320-327.

DOI: 10.1080/02670836.2015.1137410

Google Scholar

[5] H.K.D.H. Bhadeshia, R.W.K. Honeycombe, The Tempering of Martensite, third ed., Butterworth-Heinemann, Oxford, 2006. Reference to a chapter in an edited book: Steels-Microstructure and Properties.

DOI: 10.1016/b978-0-08-100270-4.00009-3

Google Scholar

[6] D. Koistinen, R. Marburger, A General Equation Prescribing the Extent of the Austenite-Martensite Transformation in Pure Iron-Carbon Alloys and Plain Carbon Steels, Acta Metall. 7 (1959) 59-60.

DOI: 10.1016/0001-6160(59)90170-1

Google Scholar

[7] H.K.D.H. Bhadeshia, Lower Bainite, third ed., Maney Publishing, Leeds, 2015. Reference to a chapter in an edited book: Bainite in Steels.

Google Scholar

[8] Z.Y. Chang, Y.J. Li, D. Wu, Enhanced Ductility and Toughness in 2000 MPa Grade Press Hardening Steels by Auto-Tempering, Mater. Sci. Eng. 784 (2020) 139342.

DOI: 10.1016/j.msea.2020.139342

Google Scholar