Medium-Mn steels for hot forming application in the automotive industry

Shuo-shuo Li; Hai-wen Luo

doi:10.1007/s12613-020-2179-9

Volume 28 Issue 5

May 2021

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Article Navigation > International Journal of Minerals, Metallurgy and Materials > 2021 > 28(5): 741-753

Shuo-shuo Liand Hai-wen Luo, Medium-Mn steels for hot forming application in the automotive industry, Int. J. Miner. Metall. Mater., 28(2021), No. 5, pp. 741-753. https://doi.org/10.1007/s12613-020-2179-9

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Shuo-shuo Liand Hai-wen Luo, Medium-Mn steels for hot forming application in the automotive industry, Int. J. Miner. Metall. Mater., 28(2021), No. 5, pp. 741-753. https://doi.org/10.1007/s12613-020-2179-9

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Invited Review

Medium-Mn steels for hot forming application in the automotive industry

Shuo-shuo Li and
Hai-wen Luo

+ Author Affiliations

Corresponding author:
Hai-wen Luo E-mail: luohaiwen@ustb.edu.cn
Received: 20 May 2020; Revised: 28 August 2020; Accepted: 31 August 2020; Available online: 3 September 2020

Abstract

Abstract

Advanced high-strength steels have been widely used to improve the crashworthiness and lightweight of vehicles. Different from the popular cold stamping, hot forming of boron-alloyed manganese steels, such as 22MnB5, could produce ultra-high-strength steel parts without springback and with accurate control of dimensions. Moreover, hot-formed medium-Mn steels could have many advantages, including better mechanical properties and lower production cost, over hot-formed 22MnB5. This paper reviews the hot forming process in the automotive industry, hot-formed steel grades, and medium-Mn steel grades and their application in hot forming in depth. In particular, the adaptabilities of medium-Mn steels and the presently popular 22MnB5 into hot forming were compared thoroughly. Future research should focus on the technological issues encountered in hot forming of medium-Mn steels to promote their commercialization.
- medium-Mn transformation-induced plasticity steel;
- hot forming;
- mechanical properties;
- retained austenite;
- baking

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References

[1]	C.Y. Wang, J. Yang, Y. Chang, W.Q. Cao, and H. Dong, Development trend and challenge of advanced high strength automobile steels, Iron Steel, 54(2019), No. 2, p. 1.
[2]	J.T. Liang, Strengthen-Toughening Mechanism and Application Technology of 2000 MPa Grade Hot Stamping Steel [Dissertation], University of Science and Technology Beijing, Beijing, 2019, p. 1.
[3]	E. Billur, 12-Hot formed steels, [in] R. Rana and S.B. Singh, eds., Automotive Steels, Elsevier, Netherlands, 2017, p. 387.
[4]	Y. Abe, T. Ohmi, K. Mori, and T. Masuda, Improvement of formability in deep drawing of ultra-high strength steel sheets by coating of die, J. Mater. Process. Technol., 214(2014), No. 9, p. 1838. doi: 10.1016/j.jmatprotec.2014.03.023
[5]	K. Mori, K. Akita, and Y. Abe, Springback behaviour in bending of ultra-high strength steel sheets using CNC servo press, Int. J. Mach. Tools Manuf., 47(2007), No. 2, p. 321. doi: 10.1016/j.ijmachtools.2006.03.013
[6]	X.J. Jin, Y. Gong, X.H. Han, H. Du, W. Ding, B. Zhu, Y.S. Zhang, Y. Feng, M.T. Ma, B. Liang, Y. Zhao, Y. Li, J.H. Zheng, and Z.S. Zhi, A review of current state and prospect of the manufacturing and application of advanced hot stamping automobile steels, Acta Metall. Sin., 56(2020), No. 4, p. 411.
[7]	B. Hu, H.W. Luo, F. Yang, and H. Dong, Recent progress in medium-Mn steels made with new designing strategies, a review, J. Mater. Sci. Technol., 33(2017), No. 12, p. 1457. doi: 10.1016/j.jmst.2017.06.017
[8]	C.F. Kuang, Z.W. Zheng, M.L. Wang, Q. Xu, and S.G. Zhang, Effect of hot-dip galvanizing processes on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel, Int. J. Miner. Metall. Mater., 24(2017), No. 12, p. 1379. doi: 10.1007/s12613-017-1530-2
[9]	C.F. Kuang, Z.W. Zheng, G.T. Zhang, J. Chang, S.G. Zhang, and B. Liu, Effects of overaging temperature on the microstructure and properties of 600 MPa cold-rolled dual-phase steel, Int. J. Miner. Metall. Mater., 23(2016), No. 8, p. 943. doi: 10.1007/s12613-016-1310-4
[10]	H.X. Yin, A.M. Zhao, Z.Z. Zhao, X. Li, S.J. Li, H.J. Hu, and W.G. Xia, Influence of original microstructure on the transformation behavior and mechanical properties of ultra-high-strength TRIP-aided steel, Int. J. Miner. Metall. Mater., 22(2015), No. 3, p. 262. doi: 10.1007/s12613-015-1070-6
[11]	M. Mukherjee, S. Tiwari, and B. Bhattacharya, Evaluation of factors affecting the edge formability of two hot rolled multiphase steels, Int. J. Miner. Metall. Mater., 25(2018), No. 2, p. 199. doi: 10.1007/s12613-018-1563-1
[12]	Y.J. Zhao, X.P. Ren, W.C. Yang, and Y. Zang, Design of a low-alloy high-strength and high-toughness martensitic steel, Int. J. Miner. Metall. Mater., 20(2013), No. 8, p. 733. doi: 10.1007/s12613-013-0791-7
[13]	J.H. Choi, M.C. Jo, H. Lee, A. Zargaran, T. Song, S.S. Sohn, N.J. Kim, and S. Lee, Cu addition effects on TRIP to TWIP transition and tensile property improvement of ultra-high-strength austenitic high-Mn steels, Acta Mater., 166(2019), p. 246. doi: 10.1016/j.actamat.2018.12.044
[14]	Z.P. Xiong, X.P. Ren, W.P. Bao, J. Shu, S.X. Li, and H.T. Qu, Effect of high temperature and high strain rate on the dynamic mechanical properties of Fe−30Mn−3Si−4Al TWIP steel, Int. J. Miner. Metall. Mater., 20(2013), No. 9, p. 835. doi: 10.1007/s12613-013-0804-6
[15]	T. Kang, Z.Z. Zhao, J.H. Liang, J. Guo, and Y. Zhao, Effect of the austenitizing temperature on the microstructure evolution and mechanical properties of Q&P steel, Mater. Sci. Eng. A, 771(2020), art. No. 138584. doi: 10.1016/j.msea.2019.138584
[16]	H.T. Jiang, B.T. Zhuang, X.G. Duan, Y.X. Wu, and Z.X. Cai, Element distribution and diffusion behavior in Q&P steel during partitioning, Int. J. Miner. Metall. Mater., 20(2013), No. 11, p. 1050. doi: 10.1007/s12613-013-0833-1
[17]	P.H. Chen, Y.B. Li, R.Q. Li, R.P. Jiang, S.S. Zeng, and X.Q. Li, Microstructure, mechanical properties, and wear resistance of VC_p-reinforced Fe-matrix composites treated by Q&P process, Int. J. Miner. Metall. Mater., 25(2018), No. 9, p. 1060. doi: 10.1007/s12613-018-1657-9
[18]	Y. Li, G.Y. Xiao, L.B. Chen, and Y.P. Lu, Acoustic emission study of the plastic deformation of quenched and partitioned 35CrMnSiA steel, Int. J. Miner. Metall. Mater., 21(2014), No. 12, p. 1196. doi: 10.1007/s12613-014-1027-1
[19]	F. Yang, J. Zhou, Y. Han, P. Liu, H.W. Luo, and H. Dong, A novel cold-rolled medium Mn steel with an ultra-high product of tensile strength and elongation, Mater. Lett., 258(2020), art. No. 126804. doi: 10.1016/j.matlet.2019.126804
[20]	H. Karbasian and A.E. Tekkaya, A review on hot stamping, J. Mater. Process. Technol., 210(2010), No. 15, p. 2103. doi: 10.1016/j.jmatprotec.2010.07.019
[21]	A. Smith, H.W. Luo, D.N. Hanlon, J. Sietsma, and S. van Der Zwaag, Recovery processes in the ferrite phase in C–Mn steel, ISIJ Int., 44(2004), No. 7, p. 1188. doi: 10.2355/isijinternational.44.1188
[22]	T. Taylor and A. Clough, Critical review of automotive hot-stamped sheet steel from an industrial perspective, Mater. Sci. Technol., 34(2018), No. 7, p. 809. doi: 10.1080/02670836.2018.1425239
[23]	M.C. Somani, L.P. Karjalainen, M. Eriksson, and M. Oldenburg, Dimensional changes and microstructural evolution in a B-bearing steel in the simulated forming and quenching process, ISIJ Int., 41(2001), No. 4, p. 361. doi: 10.2355/isijinternational.41.361
[24]	M. Naderi, Hot Stamping of Ultra High Strength Steels [Dissertation], RWTH Aachen, Aachen, 2007.
[25]	S. Graff, T. Gerber, F.J. Lenze and S. Sikora, About the simulation of microstructure evolution in the hot sheet stamping process and the correlation of resulting mechanical properties and crash-performance, [in] Proceedings of 3rd International Conference on Hot Sheet Metal Forming of High-Performance Steel, Kassel, 2011, p. 323.
[26]	J. Zhou, B.Y. Wang, M.D. Huang, and D. Cui, Effect of hot stamping parameters on the mechanical properties and microstructure of cold-rolled 22MnB5 steel strips, Int. J. Miner. Metall. Mater., 21(2014), No. 6, p. 544. doi: 10.1007/s12613-014-0940-7
[27]	L. Lin, B.S. Li, G.M. Zhu, Y.L. Kang, and R.D. Liu, Effects of Nb on the microstructure and mechanical properties of 38MnB5 steel, Int. J. Miner. Metall. Mater., 25(2018), No. 10, p. 1181. doi: 10.1007/s12613-018-1670-z
[28]	ArcelorMittal, Steels for Hot Stamping - Usibor® and Ductibor®, ArcelorMittal [2021-4-15]. https://automotive.arcelormittal.com/products/flat/PHS/usibor_ductibor
[29]	POSCO, POSCO Product: Automotive, POSCO [2021-4-15] http://product.posco.com/homepage/product/eng/jsp/industry/s91u1000170a.jsp
[30]	T. Taylor, G. Fourlaris, and A. Clough, Effect of carbon and microalloy additions on hot-stamped boron steel, Mater. Sci. Technol., 33(2017), No. 16, p. 1964. doi: 10.1080/02670836.2017.1342018
[31]	L. Lin, B.S. Li, G.M. Zhu, Y.L. Kang, and R.D. Liu, Effect of niobium precipitation behavior on microstructure and hydrogen induced cracking of press hardening steel 22MnB5, Mater. Sci. Eng. A, 721(2018), p. 38. doi: 10.1016/j.msea.2018.02.021
[32]	H.P. Liu, X.W. Lu, X.J. Jin, H. Dong, and J. Shi, Enhanced mechanical properties of a hot stamped advanced high-strength steel treated by quenching and partitioning process, Scripta Mater., 64(2011), No. 8, p. 749. doi: 10.1016/j.scriptamat.2010.12.037
[33]	E.J. Seo, L. Cho, and B.C. De Cooman, Application of quenching and partitioning (Q&P) processing to press hardening steel, Metall. Mater. Trans. A, 45(2014), No. 9, p. 4022. doi: 10.1007/s11661-014-2316-z
[34]	B.M. Linke, T. Gerber, A. Hatscher, I. Salvatori, I. Aranguren, and M. Arribas, Impact of Si on microstructure and mechanical properties of 22MnB5 hot stamping steel treated by quenching & partitioning (Q&P), Metall. Mater. Trans. A, 49(2018), No. 1, p. 54. doi: 10.1007/s11661-017-4400-7
[35]	H.L. Cai, P. Chen, J.K. Oh, Y.R Cho, D. Wu, and H.L. Yi, Quenching and flash-partitioning enables austenite stabilization during press-hardening processing, Scripta Mater., 178(2020), p. 77. doi: 10.1016/j.scriptamat.2019.10.047
[36]	H.L. Yi, Z.Y. Chang, H.L. Cai, P.J. Du, and D.P. Yang, Strength, ductility and fracture strain of press-hardening steels, Acta Metall. Sin., 56(2020), No. 4, p. 429.
[37]	L.W. Chen and C.H. Tu, The effect of the tooling temperature on the mechanical properties of CSC-15B22 steel sheets that undergo tailored tempering, Int. J. Mater. Forming, (2020). DOI: 10.1007/s12289-020-01573-w
[38]	J.H. Kim, S.B. Lee, and B.M. Kim, Construction of process window to predict hardness in tailored tool thermomechanical treatment and its application, Metals, 9(2019), No. 1, p. 50. doi: 10.3390/met9010050
[39]	W. Cheng, H.L. Zhang, S. Fu, H. Xie, Z.W. Tang, and Z.L. Zhu, A process-performance coupled design method for hot-stamped tailor rolled blank structure, Thin-Walled Struct., 140(2019), p. 132. doi: 10.1016/j.tws.2019.03.037
[40]	K. Mori, P.F. Bariani, B.A. Behrens, A. Brosius, S. Bruschi, T. Maeno, and J. Yanagimoto, Hot stamping of ultra-high strength steel parts, CIRP Ann., 66(2017), No. 2, p. 755. doi: 10.1016/j.cirp.2017.05.007
[41]	A. Ormaetxea, A. Aramburu, and I. Belategi, Improved productivity and energy consumption on press hardening by means of mechanical servo press technology, [in] Proceedings of 4th International Conference on Hot Sheet Metal Forming of High-Performance Steel, Luleå, 2013, p. 185.
[42]	H. Lehmann, Developments in the field of schwartz heat treatment furnaces for press hardening industry, [in] Proceedings of 3rd International Conference on Hot Sheet Metal Forming of High-Performance Steel, Kassel, 2011, p. 171.
[43]	H. Aydin, E. Essadiqi, I.H. Jung, and S. Yue, Development of 3rd generation AHSS with medium Mn content alloying compositions, Mater. Sci. Eng. A, 564(2013), p. 501. doi: 10.1016/j.msea.2012.11.113
[44]	C.Y. Lee, J. Jeong, J. Han, S.J. Lee, S. Lee, and Y.K. Lee, Coupled strengthening in a medium manganese lightweight steel with an inhomogeneously grained structure of austenite, Acta Mater., 84(2015), p. 1. doi: 10.1016/j.actamat.2014.10.032
[45]	C. Zhao, C. Zhang, W.Q. Cao, and Z.G. Yang, Variation in retained austenite content and mechanical properties of 0.2C–7Mn steel after intercritical annealing, Int. J. Miner. Metall. Mater., 23(2016), No. 2, p. 161. doi: 10.1007/s12613-016-1223-2
[46]	Z.H. Cai, H. Ding, R.D.K. Misra, and H. Kong, Unique serrated flow dependence of critical stress in a hot-rolled Fe–Mn–Al–C steel, Scripta Mater., 71(2014), p. 5. doi: 10.1016/j.scriptamat.2013.09.009
[47]	S. Lee, Y. Estrin, and B.C. de Cooman, Effect of the strain rate on the TRIP–TWIP transition in austenitic Fe–12 pct Mn–0.6 pct C TWIP steel, Metall. Mater. Trans. A, 45(2014), No. 2, p. 717. doi: 10.1007/s11661-013-2028-9
[48]	H.W. Luo, C.H. Qiu, H. Dong, and J. Shi, Experimental and numerical analysis of influence of carbide on austenitisation kinetics in 5Mn TRIP steel, Mater. Sci. Technol., 30(2014), No. 11, p. 1367. doi: 10.1179/1743284713Y.0000000447
[49]	H.W. Luo, J.H. Liu, and H. Dong, A novel observation on cementite formed during intercritical annealing of medium Mn steel, Metall. Mater. Trans. A, 47(2016), No. 6, p. 3119. doi: 10.1007/s11661-016-3448-0
[50]	J.T. Benzing, J. Bentley, J.R. Mcbride, D. Ponge, and J.E. Wittig, Characterization of partitioning in a medium-Mn third-generation AHSS, Microsc. Microanal., 23(2017), No. S1, p. 402. doi: 10.1017/S1431927617002690
[51]	H.W. Luo, Comments on “Austenite stability of ultrafine-grained transformation-induced plasticity steel with Mn partitioning” by S. Lee, S.J. Lee and B.C. de Cooman. Scripta Materialia, 65 (2011) 225–228, Scripta Mater., 66(2012), No. 10, p. 829. doi: 10.1016/j.scriptamat.2012.01.017
[52]	Z.H. Cai, H. Ding, R.D.K. Misra, and Z.Y. Ying, Austenite stability and deformation behavior in a cold-rolled transformation-induced plasticity steel with medium manganese content, Acta Mater., 84(2015), p. 229. doi: 10.1016/j.actamat.2014.10.052
[53]	R.L. Miller, Ultrafine-grained microstructures and mechanical properties of alloy steels, Metall. Mater. Trans. B, 3(1972), No. 4, p. 905. doi: 10.1007/BF02647665
[54]	H.W Luo, J. Shi, C. Wang, W.Q. Cao, X.J. Sun, and H. Dong, Experimental and numerical analysis on formation of stable austenite during the intercritical annealing of 5Mn steel, Acta Mater., 59(2011), No. 10, p. 4002. doi: 10.1016/j.actamat.2011.03.025
[55]	J. Shi, X.J. Sun, M.Q. Wang, W.J. Hui, H. Dong, and W.Q. Cao, Enhanced work-hardening behavior and mechanical properties in ultrafine-grained steels with large-fractioned metastable austenite, Scripta Mater., 63(2010), No. 8, p. 815. doi: 10.1016/j.scriptamat.2010.06.023
[56]	B.B. He, B. Hu, H.W. Yen, G.J. Cheng, Z.K. Wang, H.W. Luo, and M.X. Huang, High dislocation density-induced large ductility in deformed and partitioned steels, Science, 357(2017), No. 6355, p. 1029. doi: 10.1126/science.aan0177
[57]	M.J. Merwin, Hot- and cold-rolled low-carbon manganese TRIP steels, [in] SAE Technical Paper Series, Warrendale, 2007, EPR2007010336
[58]	X.Q. Xu, Reference Value for Critical Temperature of Steels, 7th ed., Northeastern Special Steel Group, 2015. https://wenku.baidu.com/view/ac51e85689eb172dec63b709.html
[59]	Y. Chen, C.Y. Wang, H. Dong, and W.Q. Cao, Warm stamping steel and its forming technology for auto security structure parts, Forging Stamping Technol., 41(2016), No. 7, p. 43.
[60]	L. Vaissiere, J.P. Laurent, and A. Reinhardt, Development of pre-coated boron steel for applications on psa peugeot citroën and renault bodies in white, [in] SAE Technical Paper Series, Warrendale, 2002, EPR2002012048.
[61]	H. Mohrbacher, Martensitic automotive steel sheet—Fundamentals and metallurgical optimization strategies, Adv. Mater. Res., 1063(2014), p. 130. doi: 10.4028/www.scientific.net/AMR.1063.130
[62]	Y. Chang, C.Y. Wang, K.M. Zhao, H. Dong, and J.W. Yan, An introduction to medium-Mn steel: Metallurgy, mechanical properties and warm stamping process, Mater. Des., 94(2016), p. 424. doi: 10.1016/j.matdes.2016.01.048
[63]	X.D. Li, Y. Chang, C.Y. Wang, P. Hu, and H. Dong, Comparison of the hot-stamped boron-alloyed steel and the warm-stamped medium-Mn steel on microstructure and mechanical properties, Mater. Sci. Eng. A, 679(2017), p. 240. doi: 10.1016/j.msea.2016.10.045
[64]	Q. Lu, M. Eizadjou, J. Wang, A. Ceguerra, S. Ringer, H. Zhan, L. Wang, and Q. Lai, Medium-Mn martensitic steel ductilized by baking, Metall. Mater. Trans. A, 50(2019), No. 9, p. 4067. doi: 10.1007/s11661-019-05335-5
[65]	Z.R. Hou, T. Opitz, X.C. Xiong, X.M. Zhao, and H.L. Yi, Bake-partitioning in a press-hardening steel, Scripta Mater., 162(2019), p. 492. doi: 10.1016/j.scriptamat.2018.10.053
[66]	H.J. Pan, M.H. Cai, H. Ding, H.S. Huang, B. Zhu, Y.L. Wang, and Y.S. Zhang, Microstructure evolution and enhanced performance of a novel Nb–Mo microalloyed medium Mn alloy fabricated by low-temperature rolling and warm stamping, Mater. Des., 134(2017), p. 352. doi: 10.1016/j.matdes.2017.08.047
[67]	S.S. Li and H.W. Luo, A novel high-strength oxidization-resistant press hardening steel sheet requiring no Al–Si coating, [in] TMS 2020 149th Annual Meeting & Exhibition Supplemental Proceedings, The Minerals, Metals & Materials Series. Springer, Cham, 2002, p. 505.
[68]	H.L. Yi, P.J. Du, and B.G. Wang, A new invention of press-hardened steel achieving 1880 MPa tensile strength combined with 16% elongation in hot-stamped parts, [in] Proceedings of the 5th International Conference on Hot Sheet Metal Forming of High-performance Steel, Toronto, 2015, p. 725.
[69]	R. Rana, C.H. Carson, and J.G. Speer, Hot forming response of medium manganese transformation induced plasticity steels, [in] Proceedings of the 5th International Conference on Hot Sheet Metal Forming of High-performance Steel, Toronto, 2015, p. 391.
[70]	Q. Han, W. Bi, X. Jin, W. Xu, L. Wang, X. Xiong, J. Wang and P. Belager, Low temperature hot forming of medium-Mn steel, [in] Proceedings of the 5th International Conference on Hot Sheet Metal Forming of High-Performance Steel, Toronto, 2015, p. 381.
[71]	H.W. Luo, X.H. Wang, Z.B. Liu, and Z.Y. Yang, Influence of refined hierarchical martensitic microstructures on yield strength and impact toughness of ultra-high strength stainless steel, J. Mater. Sci. Technol., 51(2020), p. 130. doi: 10.1016/j.jmst.2020.04.001
[72]	H. Kong, Q. Chao, M.H. Cai, E.J. Pavlina, B. Rolfe, P.D. Hodgson, and H. Beladi, One-step quenching and partitioning treatment of a commercial low silicon boron steel, Mater. Sci. Eng. A, 707(2017), p. 538. doi: 10.1016/j.msea.2017.09.038
[73]	E.I. Galindo-Nava and P.E.J. Rivera-Díaz-Del-Castillo, Understanding the factors controlling the hardness in martensitic steels, Scripta Mater., 110(2016), p. 96. doi: 10.1016/j.scriptamat.2015.08.010
[74]	Z.C. Li, X.T. Zhang, Y.J. Mou, R.D.K. Misra, L.F. He, and H.P. Li, The impact of intercritical annealing in conjunction with warm deformation process on microstructure, mechanical properties and TRIP effect in medium-Mn TRIP steels, Mater. Sci. Eng. A, 746(2019), p. 363. doi: 10.1016/j.msea.2019.01.035
[75]	A.R. Park, J.H. Nam, M. Kim, I.S. Jang, and Y.K. Lee, Evaluations of tensile properties as a function of austenitizing temperature and springback by V-bending testing in medium-Mn steels, Mater. Sci. Eng. A, 787(2020), art. No. 139534. doi: 10.1016/j.msea.2020.139534
[76]	J.H. Nam, J. Han, and Y.K. Lee, The effects of process temperatures on the microstructure and tensile properties of warm-stamped Nb-bearing medium-Mn steel, Metall. Mater. Trans. A, 51(2020), No. 3, p. 1098. doi: 10.1007/s11661-019-05570-w
[77]	Y.H. Mu, B.Y. Wang, J. Zhou, X. Huang, and J.L. Li, Influences of hot stamping parameters on mechanical properties and microstructure of 30MnB5 and 22MnB5 quenched in flat die, J. Cent. South Univ., 25(2018), No. 4, p. 736. doi: 10.1007/s11771-018-3778-8
[78]	S. Liu, M.J. Long, S.Y. Ai, Y. Zhao, D.F. Chen, Y. Feng, H.M. Duan, and M.T. Ma, Evolution of phase transition and mechanical properties of ultra-high strength hot-stamped steel during quenching process, Metals, 10(2020), No. 1, p. 138. doi: 10.3390/met10010138
[79]	M. Windmann, T. Opitz, S. Klein, A. Röttger, and W. Theisen, Mn-alloyed high-strength steels with a reduced austenitization temperature: Thermodynamic calculations and experimental investigations, Steel Res. Int., 89(2018), No. 11, art. No. 1800166. doi: 10.1002/srin.201800166
[80]	Y. Chang, C.Y. Wang, K.M. Zhao, H. Dong, and J.W. Yan, Introduction to a third-generation automobile steel and its optimal warm-stamping process, J. Manuf. Sci. Eng., 138(2016), No. 4, art. No. 041010. doi: 10.1115/1.4031636
[81]	X.D. Li, S. Han, C.Y. Wang, Y. Chang, P. Hu, and H. Dong, Research on the warm-hot forming process and its performance evaluation for the third-generation automobile steel, J. Mech. Eng., 53(2017), No. 8, p. 35. doi: 10.3901/JME.2017.08.035
[82]	G.J. Zheng, Y. Chang, Z.Y. Fan, X.D. Li, C.Y. Wang, and H. Dong, Study of thermal forming limit of medium-Mn steel based on finite element analysis and experiments, Int. J. Adv. Manuf. Technol., 94(2018), No. 1-4, p. 133. doi: 10.1007/s00170-017-0858-0
[83]	Y. Chang, X.D. Li, C.Y. Wang, G.J. Zheng, D.X. Ren, P. Hu, and H. Dong, Determination of interfacial heat transfer coefficient and analysis of influencing factors in warm forming the third-generation automotive medium-Mn steel, Int. Commun. Heat Mass Transf., 86(2017), p. 108. doi: 10.1016/j.icheatmasstransfer.2017.05.001
[84]	G.J. Zheng, X.D. Li, Y. Chang, C.Y. Wang, and H. Dong, A comparative study on formability of the third-generation automotive medium-Mn steel and 22MnB5 steel, J. Mater. Eng. Perform., 27(2018), No. 2, p. 530. doi: 10.1007/s11665-018-3183-3
[85]	Y. Chang, S. Han, X.D. Li, C.Y. Wang, G.J. Zheng, and H. Dong, Effect of shearing clearance on formability of sheared edge of the third-generation automotive medium-Mn steel with metastable austenite, J. Mater. Process. Technol., 259(2018), p. 216. doi: 10.1016/j.jmatprotec.2018.04.038
[86]	Y. Chang, M.H. Wang, N. Wang, X.D. Li, C.Y. Wang, G.J. Zheng, D.X. Ren, and H. Dong, Investigation of forming process of the third-generation automotive medium-Mn steel part with large-fractioned metastable austenite for high formability, Mater. Sci. Eng. A, 721(2018), p. 179. doi: 10.1016/j.msea.2018.02.084
[87]	G.J. Zheng, Y. Chang, X.D. Li, C.Y. Wang, and H. Dong, Formability study of the third generation automotive medium-Mn steel, [in] 2018 IEEE International Conference on Mechatronics and Automation (ICMA), Changchun, 2018, p. 661.
[88]	C.Y. Wang, X.D. Li, S. Han, L. Zhang, Y. Chang, W.Q. Cao, and H. Dong, Warm stamping technology of the medium manganese steel, Steel Res. Int., 89(2018), No. 9, art. No. 1700360. doi: 10.1002/srin.201700360
[89]	X.D. Li, Y. Chang, C.Y. Wang, S. Han, D.X. Ren, P. Hu, and H. Dong, Investigation on microstructure and martensitic transformation mechanism for the warm-stamped third-generation automotive medium-Mn steel, J. Eng. Mater. Technol., 139(2017), No. 4, art. No. 041009. doi: 10.1115/1.4037017
[90]	C.Y. Wang, W.Q. Cao, and H. Dong, The third generation automobile steel of medium manganese and its advantages, [in] The 11th Annual Conference on China Iron and Steel-S07: Automotive Steel, Beijing, 2017, p. 94.
[91]	S.L. Li, C.Y. Wang, Y.T. Wang, Y. Chang, and H. Dong, Warm stamping of medium-Mn steel, J. Iron Steel Res., 28(2016), No. 11, p. 46.
[92]	C.Y. Wang, M.B. Zhou, X.D. Li, H.L. Zhao, W.Q. Cao, and H. Dong, Evaluation of microstructure and properties of warm stamped medium manganese steel, Iron Steel, 54(2019), No. 10, p. 58.
[93]	German Automobile Industry Association, VDA 238-100: Plate Bending Test for Metallic Materials, German Automobile Industry Association. Berlin, 2010.
[94]	Q. Lu, J. Wang, and Y. Liu, Impact toughness of a medium-Mn steel after hot stamping, [in] Proceeding of the 6th International Conference on Hot Sheet Metal Forming of High-Performance Steel, Atlanta, 2017, p. 737.
[95]	J.P. Xu, H. Fu, Z. Wang, Y. Yan, and J.X. Li, Research progress and prospect of medium manganese steel, Chin. J. Eng., 41(2019), No. 5, p. 557.
[96]	B. Hu and H.W. Luo, A novel two-step intercritical annealing process to improve mechanical properties of medium Mn steel, Acta Mater., 176(2019), p. 250. doi: 10.1016/j.actamat.2019.07.014
[97]	B. Hu, B.B. He, G.J. Cheng, H.W. Yen, M.X. Huang, and H.W. Luo, Super-high-strength and formable medium Mn steel manufactured by warm rolling process, Acta Mater, 174(2019), p. 131. doi: 10.1016/j.actamat.2019.05.043
[98]	J.H. Han, J.H. Nam, and Y.K. Lee, The mechanism of hydrogen embrittlement in intercritically annealed medium Mn TRIP steel, Acta Mater., 113(2016), p. 1. doi: 10.1016/j.actamat.2016.04.038
[99]	J.X. Li, W. Wang, Y. Zhou, S.G. Liu, H. Fu, Z. Wang, and B. Kan, A review of research status of hydrogen embrittlement for automotive advanced high-strength steels, Acta Metall. Sin., 56(2020), No. 4, p. 444.
[100]	D.W. Fan and B.C. de Cooman, State-of-the-knowledge on coating systems for hot stamped parts, Steel Res. Int., 83(2012), No. 5, p. 412. doi: 10.1002/srin.201100292
[101]	S.S. Li, P.Y. Wen, S.L. Li, W.W. Song, Y.D. Wang, and H.W. Luo, A novel medium-Mn steel with superior mechanical properties and marginal oxidization after press hardening, Acta Mater., 205(2021), art. No. 116567. doi: 10.1016/j.actamat.2020.116567
[102]	M. Pouranvari and S.P.H. Marashi, Critical review of automotive steels spot welding: Process, structure and properties, Sci. Technol. Weld. Joining, 18(2013), No. 5, p. 361. doi: 10.1179/1362171813Y.0000000120
[103]	G. Park, K. Kim, S. Uhm, and C. Lee, A comparison of cross-tension properties and fracture behavior between similar and dissimilar resistance spot-weldments in medium-Mn TRIP steel, Mater. Sci. Eng. A, 752(2019), p. 206. doi: 10.1016/j.msea.2019.03.023
[104]	Q. Jia, L. Liu, W. Guo, Y. Peng, G.S. Zou, Z.L. Tian, and Y.N. Zhou, Microstructure and tensile-shear properties of resistance spot-welded medium Mn steel, Metals, 8(2018), No. 1, p. 48. doi: 10.3390/met8010048
[105]	N. Lun, D.C. Saha, A. Macwan, H. Pan, L. Wang, F. Goodwin, and Y. Zhou, Microstructure and mechanical properties of fibre laser welded medium manganese TRIP steel, Mater. Des., 131(2017), p. 450. doi: 10.1016/j.matdes.2017.06.037
[106]	S.S. Li, S.L. Yang, Q. Lu, H.W. Luo, and W. Tao, A novel shim-assisted resistance spot welding process to improve weldability of medium-Mn transformation-induced plasticity steel, Metall. Mater. Trans. B, 50(2019), No. 1, p. 1. doi: 10.1007/s11663-018-1463-9
[107]	G. Park, K. Kim, S. Uhm, and C. Lee, Remarkable improvement in resistance spot weldability of medium-Mn TRIP steel by paint-baking heat treatment, Mater. Sci. Eng. A, 766(2019), art. No. 138401. doi: 10.1016/j.msea.2019.138401
[108]	X.J. Di, S.J. Deng, and B.S. Wang, Effect of pulse current on mechanical properties and dendritic morphology of modified medium manganese steel welds metal, Mater. Des., 66(2015), p. 169. doi: 10.1016/j.matdes.2014.10.050
[109]	X.J. Di, M. Li, Z.W. Yang, B.S. Wang, and X.J. Guo, Microstructural evolution, coarsening behavior of vanadium carbide and mechanical properties in the simulated heat-affected zone of modified medium manganese steel, Mater. Des., 96(2016), p. 232. doi: 10.1016/j.matdes.2016.02.038