MSA  Vol.11 No.12 , December 2020
Development of Tailored Structure and Tensile Properties of Thermomechanical Treated Micro Alloyed Low Carbon Dual Phase Steel
Abstract: Direct hot rolled dual phase steel production represents a challenging route, compared with cold rolled and intercritical annealing process, due to complex and sophisticated control of the hot strip mill processing parameters. Instead, high technology compact slab production plant offers economic advantages, adequate control and prompt use of the advanced thermomechanical controlled rolling. The current work aims to obtain different structures and tensile properties by physical simulation of direct hot rolled niobium micro alloyed dual phase low carbon steel by varying the metallurgical temperatures of hot strip mill plant. This starts with adaptation of the chemical analysis of a low carbon content to fall far from the undesired peritectic region to avoid slab cracking during casting. Thermodynamic and kinetics calculations by Thermo-Calc 2020 and JMat pro software are used to define the transformation’s temperatures Ae1 and Ae3 as well as processing temperatures; namely of reheating, finishing rolling, step cooling and coiling temperatures. The results show that the increase of finishing rolling temperature from 780°C to 840°C or decreasing either of step cooling duration at ferrite bay from 7 to 4 seconds, enhances yield and tensile strengths, all due to more martensite volume fraction formation. The yield and tensile strengths also increase with decreasing coiling temperature from 330°C to 180°C, which is explained due to the increase of dislocation densities resulted from the sudden shape change during martensite formation at the lower coiling temperature in additional to the self-tempering of martensite formed at higher coiling temperatures which soften the dual phase steel.
Cite this paper: Khalifa, H. , Megahed, G. , El-Bitar, T. and Taha, M. (2020) Development of Tailored Structure and Tensile Properties of Thermomechanical Treated Micro Alloyed Low Carbon Dual Phase Steel. Materials Sciences and Applications, 11, 851-866. doi: 10.4236/msa.2020.1112056.

[1]   Kumar, N., Gulab, M.J. and Kumar, B.R. (2019) Importance of Martensite Spatial Distribution at Large Volume Fractions in Imparting Ductility in High-Strength Dual-Phase Steel. Journal of Materials Engineering and Performance, 28, 1391-1401.

[2]   Peng, F., Xu, Y., Li, J., Gu, X. and Wang, X. (2019) Interaction of Martensite and Bainite Transformations and Its Dependence on Quenching Temperature in Intercritical Quenching and Partitioning Steels. Materials and Design, 181, Article ID: 107921.

[3]   Dai, J., Meng, Q. and Zheng, H. (2020) High-Strength Dual-Phase Steel Produced through Fast Heating Annealing Method. Results in Materials, 5, Article ID: 100069.

[4]   Shukla, N., Das, S., Maji, S., Chowdhury, S.R. and Show, B.K. (2015) Effect of Pre-Intercritical Annealing Treatments on the Microstructure and Mechanical Properties of 0.33% Carbon Dual-Phase Steel. Journal of Materials Engineering and Performance, 24, 4958-4965.

[5]   Zhao, X., Huang, B., Chen, H., Ma, J., Wang, C. and Yang, Y. (2020) Influence of Intercritical Quenching Temperature on Microstructure, Mechanical Properties and Corrosion Resistance of Dual-Phase Steel. Journal of Materials Engineering and Performance, 29, 4446-4456.

[6]   Deng, Y.G., Li, Y., Di, H. and Misra, R.D.K. (2019) Effect of Heating Rate during Continuous Annealing on Microstructure and Mechanical Properties of High-Strength Dual-Phase Steel. Journal of Materials Engineering and Performance, 28, 4556-4564.

[7]   Srivastava, A.K., Patel, N.K., Kumar, B.R., Sharma, A. and Ahn, B. (2020) Strength-Ductility Trade-Off in Dual-Phase Steel Tailored via Controlled Phase Transformation. Journal of Materials Engineering and Performance, 29, 2783-2791.

[8]   Furukawa, T., Tanion, M., Morikawa, H. and Endo, M. (1984) Effects of Composition and Processing Factors on the Mechanical Properties of As-Hot-Rolled Dual-Phase Steels. Transactions of the Iron and Steel Institute of Japan, 4, 113-121.

[9]   Ji, L.K., Xu, T., Zhang, J.M., Wang, H.T., Tong, M.X., Zhu, R.H. and Zhou, G.S. (2017) The Microstructure Evolution of Dual-Phase Pipeline Steel with Plastic Deformation at Different Strain Rates. Journal of Materials Engineering and Performance, 26, 3104-3111.

[10]   Kumar, S. and Desai, R. (2019) Effect of Boron Micro-Alloying on Microstructure and Corrosion Behavior of Dual-Phase Steel. Journal of Materials Engineering and Performance, 28, 6228-6236.

[11]   Saastamoinen, A., Kaijalainen, A., Porter, D. and Suikkanen, P. (2017) The Effect of Thermomechanical Treatment and Tempering on the Subsurface Microstructure and Bendability of Direct-Quenched Low-Carbon Strip Steel. Materials Characterization, 134, 172-181.

[12]   Xu, S.S., Li, J.P., Cui, Y., Zhang, Y., Sun, L.X., Li, J., Luan, J.H., Jiao, Z.B., Wang, L., Liu, C.T. and Zhang, Z.W. (2020) Mechanical Properties and Deformation Mechanisms of a Novel Austenite-Martensite Dual Phase Steel. International Journal of Plasticity, 128, Article ID: 102677.

[13]   Chen, C.Y., Lib, C.H., et al. (2020) A Novel Technique for Developing a Dual-Phase Steel with a Lower Strength Difference between Ferrite and Martensite. Materials Today Communications, 23, Article ID: 100895.

[14]   Calcagnotto, M., Ponge, D. and Raabe, D. (2010) Effect of Grain Refinement to 1 μm Strength and Toughness of Dual-Phase Steels. Materials Science and Engineering A, 527, 7832-7840.

[15]   Calcagnotto, M., Adachi, Y., Ponge, D. and Raabe, D. (2011) Deformation and Fracture Mechanisms in Fine- and Ultrafine-Grained Ferrite/Martensite Dual-Phase Steels and the Effect of Aging. Acta Materialia, 59, 658-670.

[16]   Zhao, Z., Wang, X., Qiao, G., Zhang, S., Liao, B. and Xiao, F. (2019) Effect of Bainite Morphology on Deformation Compatibility of Mesostructure in Ferrite/Bainite Dual-Phase Steel: Mesostructure-Based Finite Element Analysis. Materials and Design, 180, Article ID: 107870.

[17]   Soliman, M. and Palkowski, H. (2015) Influence of Hot Working Parameters on Microstructure Evolution, Tensile Behavior and Strain Aging Potential of Bainitic Pipeline Steel. Materials and Design, 88, 759-773.

[18]   Podder, A.S., Murugaiyan, A., Pandit, A., Chandra, S., Bhattacharjee, D. and Ray, R. (2006) Phase Transformations in Two C-Mn-Si-Cr Dual Phase Steels. ISIJ International, 46, 1489-1494.

[19]   Gurumurthy, B., Sharma, S. and Kini, A. (2018) Ferrite-Bainite Dual Phase Structure and Mechanical Characterization of AISI 4340 Steel. Materials Today: Proceedings, 5, 24907-24914.

[20]   Soliman, M. and Palkowski, H. (2020) Tensile Properties and Bake Hardening Response of Dual Phase Steels with Varied Martensite Volume Fraction. Materials Science & Engineering A, 777, Article ID: 139044.

[21]   Bleck, W., Homberg, D., Suwanpinij, U. and Togobytska, P. (2014) Optimal Control of a Cooling Line for Production of Hot Rolled Dual Phase Steel. Steel Research International, 85, 1328-1333.

[22]   Olasolo, M., Uranga, P., Rodriguez, M. and Lopez, B. (2011) Effect of Austenite Microstructure and Cooling Rate on Transformation Characteristics in a Low Carbon Nb-V Microalloyed Steel. Materials Science and Engineering A, 528, 2559-2569.

[23]   Mecozzi, M.G., Sietsma, J. and Van der Zwaag, S. (2006) Analysis of γ→α Transformation in a Nb Micro-Alloyed C-Mn Steel by Phase Field Modelling. Acta Materialia, 54, 1431-1440.

[24]   Lee, H.-Y., Park, K.-S., Lee, J.-H., Heo, Y.-U., Suh, D.-W. and Bhadeshia, H.K.D.H. (2014) Dissolution Behavior of NbC during Slab Reheating. ISIJ International, 54, 1677-1681.

[25]   ASTM Int. (2019) ASTM E562-19, Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count.

[26]   ASTM Int. (2013) ASTM E112-13, Standard Test Methods for Determining Average Grain Size.

[27]   ASTM Int. (2013) ASTM E8-13a, Standard Test Methods for Tension Testing of Metallic Materials.

[28]   Tsai, S.-P., Jen, C.-H., Yen, H.-W., Chen, C.-Y., et al. (2017) Effects of Interphase TiC Precipitates on Tensile Properties and Dislocation Structures in a Dual Phase Steel. Materials Characterization, 123, 153-158.