Mechanism of Dynamic Strain-Induced Ferrite Transformation in a 3Mn-0.2C Medium Mn Steel

doi:10.11900/0412.1961.2021.00192

Acta Metall Sin

2022, Vol. 58

Issue (5): 649-659 DOI: 10.11900/0412.1961.2021.00192

Research paper

Current Issue | Archive | Adv Search

Mechanism of Dynamic Strain-Induced Ferrite Transformation in a 3Mn-0.2C Medium Mn Steel

SUN Yi¹^,², ZHENG Qinyuan²^,³, HU Baojia²^,³, WANG Ping¹(

), ZHENG Chengwu²^,³(

), LI Dianzhong²^,³

^1.Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China
^2.Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
^3.School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China

Cite this article:

SUN Yi, ZHENG Qinyuan, HU Baojia, WANG Ping, ZHENG Chengwu, LI Dianzhong. Mechanism of Dynamic Strain-Induced Ferrite Transformation in a 3Mn-0.2C Medium Mn Steel. Acta Metall Sin, 2022, 58(5): 649-659.

Download:

HTML

PDF(5862KB)
Export: BibTeX | EndNote (RIS)

Abstract

Medium Mn steels (MMSs) have Mn contents of 3%-12% (mass fraction), and have been energetically investigated as the most promising candidates of the third-generation advanced high-strength steel. Their phase transformations and microstructures during various heat treatments and thermomechanical processes have received wide attention with the purpose to achieve an optimal balance of cost-efficient alloying compositions and mechanical properties. The aim of this work is to investigate the microstructural behavior of deformation-induced ferrite transformation (DIFT), starting from austenite, which occurs in MMS. Then, improved understandings of the formation of ultrafine ferrite via the DIFT and conservation of this microstructure during the post-deformation period can be obtained. For this purpose, a 3Mn-0.2C MMS with lower contents of alloying elements was selected. Microstructures and alloying element distributions of the thermomechanically processed samples were analyzed via EBSD and EPMA. The results showed that the DIFT occurred in the thermomechanically processed 3Mn-0.2C MMS in the α + γ region. Characteristic multiphase microstructures consisting isolated martensite and fine-grained equiaxed ferrite concomitant with fine islands of retained austenite dispersed between ferrite grains can be obtained. During the DIFT, the enhanced nucleation of ferrite at α/γ interfaces can not only increase the ferrite nucleation density but also facilitate extensive impingement among the neighboring grains. Formation of ultrafine ferrite via the DIFT in MMS can be interpreted in terms of unsaturated nucleation and limited growth. In addition, partitioning of Mn between the ultrafine ferrite and austenite is accelerated during the DIFT such that a large number of Mn-enriched fine islands of austenite are left untransformed at the α/α grain boundaries or at triple junctions. These islands of austenite are considered to play critical roles not only for obtaining retained austenite at room temperature but also for conserving the ultrafine microstructure of the DIFT during the post-deformation processing.

Key words: hot deformation ultra-fine grained ferrite Mn partitioning deformation induced ferrite transformation medium Mn steel

Received: 07 May 2021

ZTFLH:

TG142.1

Fund: National Natural Science Foundation of China(52071322);National Natural Science Foundation of China(51771192);National Natural Science Foundation of China(U1708252)

About author: WANG Ping, professor, Tel: (024)83684630, E-mail: wping@epm.neu.edu.cn
ZHENG Chengwu, associate professor, Tel: (024)23971973, E-mail: cwzheng@imr.ac.cn

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	Yi SUN
	Qinyuan ZHENG
	Baojia HU
	Ping WANG
	Chengwu ZHENG
	Dianzhong LI

URL:

https://www.ams.org.cn/EN/10.11900/0412.1961.2021.00192 OR https://www.ams.org.cn/EN/Y2022/V58/I5/649

Fig.1 Schematics showing the thermal-mechanical cycles used for the deformation induced ferrite transformation (a) and the isothermal ferrite transformation (b) of the 3Mn-0.2C medium Mn steel (MMS) (A_e3 is the highest temperature at which ferrite and austenite phases can coexist in equilibrium. A_e1 is the lowest temperature at which ferrite, cementite, and austenite phases can coexist in equilibrium in the steel)

Fig.2 True stress-true strain curve of the 3Mn-0.2C MMS (a) and corresponding EBSD maps at strains of ε = 0.22 (b), 0.51 (c), and 0.92 (d) at temperature of T = 660^oC and strain rate of $ε ˙$ = 0.001 s^-1(The green and blue lines in Figs.2b~d represent boundaries with 2° ≤ θ < 15° and θ ≥ 15°, respectively. θ is misorientation angle of the boundary. M—martensite, α—ferrite)

Fig.3 SEM images of 3Mn-0.2C MMS soaking at T = 660^oC for 1800 s (a) and deformed to ε = 0.51 with $ε ˙$ = 0.001 s^-1 at T = 660^oC (b) (RA—retained austenite)

Fig.4 EBSD images of the 3Mn-0.2C MMS at ε = 0.22 (a), 0.51 (b), and 0.92 (c) with the hot deformation under T = 660^oC and $ε ˙$ = 0.001 s^-1 (The yellow arrows in Fig.4b indicate the ferrite grains formed along the intragranular deformation bands. The green and blue lines in the figures represent boundaries with 2° ≤ θ < 15° and θ ≥ 15°, respectively)

Fig.5 SEM image of the 3Mn-0.2C MMS deformed to ε = 0.92 under T = 660^oC and $ε ˙$ = 0.001 s^-1, and the associated alloying elements distributions of C, Si, and Mn

Fig. 6 EBSD images of the 3Mn-0.2C MMS deformed to ε = 0.92 under T = 660^oC and $ε ˙$ = 0.001 s^-1 (a), and the 3Mn-0.2C MMS continuously soaked for 1000 s after deformation at the same temperature (b) (The green and blue lines in the figures represent boundaries with 2° ≤ θ < 15° and θ ≥ 15°, respectively)

Fig.7 SEM images and the distributions of Mn of the 3Mn-0.2C MMS deformed to ε = 0.92 under T = 660^oC and $ε ˙$ = 0.001 s^-1 (a), and the 3Mn-0.2C MMS continuously soaked for 1000 s after deformation at the same temperature (b)

Fig.8 EBSD images of the 3Mn-0.2C MMS deformed to ε = 0.92 at T = 660^oC with $ε ˙$ = 0.1 s^-1 (a), 0.01 s^-1 (b), and 0.001 s^-1 (c) ^{(The green and blue lines in the figures represent boundaries with 2° ≤ θ < 15° and θ ≥ 15°, respectively)}

Fig.9 SEM images and the distributions of C and Mn of the 3Mn-0.2C MMS deformed to ε = 0.92 at T = 660^oC with $ε ˙$ = 0.1 s^-1 (a), 0.01 s^-1 (b), and 0.001 s^-1 (c)

Fig.10 Schematics of the microstructure evolution during the deformation induced ferrite transformation of the medium Mn steel (a-d)

1	Wei Y J, Li Y Q, Zhu L C, et al. Evading the strength-ductility trade-off dilemma in steel through gradient hierarchical nanotwins [J]. Nat. Commun., 2014, 5: 3580 doi: 10.1038/ncomms4580
2	Bouaziz O, Zurob H, Huang M X. Driving force and logic of development of advanced high strength steels for automotive applications [J]. Steel Res Int., 2013, 84: 937
3	Tang D, Zhao Z Z, Mi Z L, et al. Advanced High Strength Strip Steel for Automobile [M]. Beijing: Metallurgical Industry Press, 2016: 1
	唐荻, 赵征志, 米振莉等. 汽车用先进高强板带钢 [M]. 北京: 冶金工业出版社, 2016: 1
4	Raabe D, Sun B H, Silva A K D, et al. Current challenges and opportunities in microstructure-related properties of advanced high-strength steels [J]. Metall. Mater. Trans., 2020, 51A: 5517
5	Fonstein N. Advanced High Strength Sheet Steels: Physical Metallurgy, Design, Processing, and Properties [M]. New York: Springer, 2015: 1
6	Wang C Y, Chang Y, Zhou F L, et al. M3 microstructure control theory and technology of the third-generation automotive steels with high strength and high ductility [J]. Acta Metall. Sin., 2020, 56: 400
	王存宇, 常颖, 周峰峦等. 高强度高塑性第三代汽车钢的M3组织调控理论与技术 [J]. 金属学报, 2020, 56: 400 doi: 10.11900/0412.1961.2019.00371
7	Zhao Z Z, Chen W J, Gao P F, et al. Progress and perspective of advanced high strength automotive steel [J]. J. Iron Steel Res., 2020, 32: 1059
	赵征志, 陈伟健, 高鹏飞等. 先进高强度汽车用钢研究进展及展望 [J]. 钢铁研究学报, 2020, 32: 1059
8	Lee Y K, Han J. Current opinion in medium manganese steel [J]. Mater. Sci. Technol., 2015, 31: 843 doi: 10.1179/1743284714Y.0000000722
9	Suh D W, Kim S J. Medium Mn transformation-induced plasticity steels: Recent progress and challenges [J]. Scr. Mater., 2017, 126: 63 doi: 10.1016/j.scriptamat.2016.07.013
10	Ma Y. Medium-manganese steels processed by austenite-reverted-transformation annealing for automotive applications [J]. Mater. Sci. Technol., 2017, 33: 1713 doi: 10.1080/02670836.2017.1312208
11	Liu L, He B B, Huang M X. The role of transformation-induced plasticity in the development of advanced high strength steels [J]. Adv. Eng. Mater., 2018, 20: 1701083 doi: 10.1002/adem.201701083
12	Jacques P J. Transformation-induced plasticity for high strength formable steels [J]. Curr. Opin. Solid State Mater. Sci., 2004, 8: 259 doi: 10.1016/j.cossms.2004.09.006
13	Lee S, Lee S J, De Cooman B C. Austenite stability of ultrafine-grained transformation-induced plasticity steel with Mn partitioning [J]. Scr. Mater., 2011, 65: 225 doi: 10.1016/j.scriptamat.2011.04.010
14	Cai Z H, Ding H, Misra R D K, et al. Austenite stability and deformation behavior in a cold-rolled transformation-induced plasticity steel with medium manganese content [J]. Acta Mater., 2015, 84: 229 doi: 10.1016/j.actamat.2014.10.052
15	Miller R L. Ultrafine-grained microstructures and mechanical properties of alloy steels [J]. Metall. Mater. Trans., 1972, 3B: 905
16	Zhang X L, Hou H F, Liu T, et al. Microstructure and mechanical properties of a novel heterogeneous cold-rolled medium Mn steel with high product of strength and ductility [J]. Chin. J. Mater. Res., 2019, 33: 927
	张喜亮, 侯华峰, 刘涛等. 一种新型高强塑积异质冷轧中锰钢的力学性能 [J]. 材料研究学报, 2019, 33: 927
17	Li Y, Li W, Min N, et al. Mechanical response of a medium manganese steel with encapsulated austenite [J]. Scr. Mater., 2020, 178: 211 doi: 10.1016/j.scriptamat.2019.11.033
18	Ding R, Yao Y J, Sun B H, et al. Chemical boundary engineering: A new route toward lean, ultrastrong yet ductile steels [J]. Sci. Adv., 2020, 6: eaay1430 doi: 10.1126/sciadv.aay1430
19	He B B, Hu B, Yen H W, et al. High dislocation density-induced large ductility in deformed and partitioned steels [J]. Science, 2017, 357: 1029 doi: 10.1126/science.aan0177 pmid: 28839008
20	Hu B, Luo H W, Yang F, et al. Recent progress in medium Mn steels made with new designing strategies, a review [J]. J. Mater. Sci. Technol., 2017, 33: 1457 doi: 10.1016/j.jmst.2017.06.017
21	Suh D W, Park S J, Lee T H, et al. Influence of Al on the microstructural evolution and mechanical behavior of low-carbon, manganese transformation-induced-plasticity steel [J]. Metall. Mater. Trans., 2010, 41A: 397
22	Cai M H, Li Z, Chao Q, et al. A novel Mo and Nb microalloyed medium Mn TRIP Steel with maximal ultimate strength and moderate ductility [J]. Metall. Mater. Trans., 2014, 45A: 5624
23	Shao C W, Hui W J, Zhang Y J, et al. Microstructure and mechanical properties of a novel cold rolled medium-Mn steel with superior strength and ductility [J]. Acta Metall. Sin., 2019, 55: 191
	邵成伟, 惠卫军, 张永健等. 一种新型高强度高塑性冷轧中锰钢的组织和力学性能 [J]. 金属学报, 2019, 55: 191 doi: 10.11900/0412.1961.2018.00081
24	Li S S, Wen P Y, Li S L, et al. A novel medium-Mn steel with superior mechanical properties and marginal oxidization after press hardening [J]. Acta Mater., 2021, 205: 116567 doi: 10.1016/j.actamat.2020.116567
25	Liu D G, Cai M H, Ding H, et al. Control of inter/intra-granular κ-carbides and its influence on overall mechanical properties of a Fe-11Mn-10Al-1.25C low density steel [J]. Mater. Sci. Eng., 2018, A715: 25
26	Zhao J W, Jiang Z Y. Thermomechanical processing of advanced high strength steels [J]. Prog. Mater. Sci., 2018, 94: 174 doi: 10.1016/j.pmatsci.2018.01.006
27	Essadiqi E, Jonas J J. Effect of deformation on the austenite-to-ferrite transformation in a plain carbon and two microalloyed steels [J]. Metall. Trans., 1988, 19A: 417
28	Dong H, Sun X J. Deformation induced ferrite transformation in low carbon steels [J]. Curr. Opin. Solid State Mater. Sci., 2005, 9: 269 doi: 10.1016/j.cossms.2006.02.014
29	Hurley P J, Hodgson P D. Formation of ultra-fine ferrite in hot rolled strip: Potential mechanisms for grain refinement [J]. Mater. Sci. Eng., 2001, A302: 206
30	Wen Y Q. Ultra-Fine Grained Steels [M]. Beijing: Metallurgical Industry Press, 2003: 1
	翁宇庆. 超细晶钢 [M]. 北京: 冶金工业出版社, 2003: 1
31	Chen M M, Wu R M, Liu H P, et al. An ultrahigh strength steel produced through deformation-induced ferrite transformation and Q&P process [J]. Sci. China Technol. Sci., 2012, 55: 1827 doi: 10.1007/s11431-012-4880-z
32	Ito A, Matsui Y, Bai Y, et al. Ferrite transformation and mechanical properties of medium manganese steel [A]. Proceedings of 1st International Conference on Automobile Steel and 3rd International Conference on High Manganese Steels [C]. Beijing: Metallurgical Industry Press, 2016: 123
33	Hou F F, Bai Y, Shibata A, et al. Microstructure evolution during thermomechanical processing in 3Mn-0.1C medium-Mn steel [J]. Mater. Sci. Technol., 2019, 35: 2101 doi: 10.1080/02670836.2018.1548099
34	Beladi H, Kelly G L, Hodgson P D. Ultrafine grained structure formation in steels using dynamic strain induced transformation processing [J]. Int. Mater. Rev., 2007, 52: 14 doi: 10.1179/174328006X102538
35	Ghosh C, Aranas C, Jonas J J. Dynamic transformation of deformed austenite at temperatures above the A_e3 [J]. Prog. Mater. Sci., 2016, 82: 151 doi: 10.1016/j.pmatsci.2016.04.004
36	Nakada N, Mizutani K, Tsuchiyama T, et al. Difference in transformation behavior between ferrite and austenite formations in medium manganese steel [J]. Acta Mater., 2014, 65: 251 doi: 10.1016/j.actamat.2013.10.067
37	Shibata A, Takeda Y, Park N, et al. Nature of dynamic ferrite transformation revealed by in-situ neutron diffraction analysis during thermomechanical processing [J]. Scr. Mater., 2019, 165: 44 doi: 10.1016/j.scriptamat.2019.02.017
38	Zheng C W, Xiao N M, Hao L H, et al. Numerical simulation of dynamic strain-induced austenite-ferrite transformation in a low carbon steel [J]. Acta Mater., 2009, 57: 2956 doi: 10.1016/j.actamat.2009.03.005
39	Zheng C W, Li D Z, Lu S P, et al. On the ferrite refinement during the dynamic strain-induced transformation: A cellular automaton modeling [J]. Scr. Mater., 2008, 58: 838 doi: 10.1016/j.scriptamat.2007.12.040

[1]	LI Fulin, FU Rui, BAI Yunrui, MENG Lingchao, TAN Haibing, ZHONG Yan, TIAN Wei, DU Jinhui, TIAN Zhiling. Effects of Initial Grain Size and Strengthening Phase on Thermal Deformation and Recrystallization Behavior of GH4096 Superalloy[J]. 金属学报, 2023, 59(7): 855-870.
[2]	SHEN Guohui, HU Bin, YANG Zhanbing, LUO Haiwen. Influence of Tempering Temperature on Mechanical Properties and Microstructures of High-Al-Contained Medium Mn Steel Having δ-Ferrite[J]. 金属学报, 2022, 58(2): 165-174.
[3]	YAN Mengqi, CHEN Liquan, YANG Ping, HUANG Lijun, TONG Jianbo, LI Huanfeng, GUO Pengda. Effect of Hot Deformation Parameters on the Evolution of Microstructure and Texture of β Phase in TC18 Titanium Alloy[J]. 金属学报, 2021, 57(7): 880-890.
[4]	NI Ke, YANG Yinhui, CAO Jianchun, WANG Liuhang, LIU Zehui, QIAN Hao. Softening Behavior of 18.7Cr-1.0Ni-5.8Mn-0.2N Low Nickel-Type Duplex Stainless Steel During Hot Compression Deformation Under Large Strain[J]. 金属学报, 2021, 57(2): 224-236.
[5]	LIU Chao, YAO Zhihao, JIANG He, DONG Jianxin. The Feasibility and Process Control of Uniform Equiaxed Grains by Hot Deformation in GH4720Li Alloy with Millimeter-Level Coarse Grains[J]. 金属学报, 2021, 57(10): 1309-1319.
[6]	ZHOU Li, LI Ming, WANG Quanzhao, CUI Chao, XIAO Bolv, MA Zongyi. Study of the Hot Deformation and Processing Map of 31%B₄Cp/6061Al Composites[J]. 金属学报, 2020, 56(8): 1155-1164.
[7]	CHEN Wenxiong, HU Baojia, JIA Chunni, ZHENG Chengwu, LI Dianzhong. Post-Dynamic Softening of Austenite in a Ni-30%Fe Model Alloy After Hot Deformation[J]. 金属学报, 2020, 56(6): 874-884.
[8]	ZHANG Yong, LI Xinxu, WEI Kang, WAN Zhipeng, JIA Chonglin, WANG Tao, LI Zhao, SUN Yu, LIANG Hongyan. Hot Deformation Characteristics of Novel Wrought Superalloy GH4975 Extruded Rod Used for 850 ℃ Turbine Disc[J]. 金属学报, 2020, 56(10): 1401-1410.
[9]	MA Kai, ZHANG Xingxing, WANG Dong, WANG Quanzhao, LIU Zhenyu, XIAO Bolv, MA Zongyi. Optimization and Simulation of Deformation Parameters of SiC/2009Al Composites[J]. 金属学报, 2019, 55(10): 1329-1337.
[10]	Xiting ZHONG, Lei WANG, Feng LIU. Study on Formation Mechanism of Necklace Structure in Discontinuous Dynamic Recrystallization of Incoloy 028[J]. 金属学报, 2018, 54(7): 969-980.
[11]	Feng YANG, Haiwen LUO, Han DONG. Effects of Intercritical Annealing Temperature on the Tensile Behavior of Cold Rolled 7Mn Steel and the Constitutive Modeling[J]. 金属学报, 2018, 54(6): 859-867.
[12]	Yusen SU, Yinhui YANG, Jianchun CAO, Yuliang BAI. Research on Hot Working Behavior of Low-NickelDuplex Stainless Steel 2101[J]. 金属学报, 2018, 54(4): 485-493.
[13]	Ming ZHANG, Guoquan LIU, Benfu HU. Effect of Microstructure Instability on Hot Plasticity During Thermomechanical Processing in PM Nickel-Based Superalloy[J]. 金属学报, 2017, 53(11): 1469-1477.
[14]	Cunyu WANG,Ying CHANG,Jie YANG,Kunmin ZHAO,Han DONG. THE COMBINED EFFECT OF HOT DEFORMATION PLUS QUENCHING AND PARTITIONING TREATMENT ON MARTENSITE TRANSFORMATION OF LOW CARBON ALLOYED STEEL[J]. 金属学报, 2015, 51(8): 913-919.
[15]	Xiaoyun YUAN, Liqing CHEN. HOT DEFORMATION AT ELEVATED TEMPERATURE AND RECRYSTALLIZATION BEHAVIOR OF A HIGH MANGANESE AUSTENITIC TWIP STEEL[J]. 金属学报, 2015, 51(6): 651-658.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed