Synergistic Effect of Magnetic Field and Grain Size on Martensite Nucleation and Variant Selection
YUAN Jiahua1, ZHANG Qiuhong2, WANG Jinliang3, WANG Lingyu1, WANG Chenchong1, XU Wei1()
1.State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China 2.School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China 3.School of Mechanical and Power Engineering, Guangdong Ocean University, Zhanjiang 524088, China
Cite this article:
YUAN Jiahua, ZHANG Qiuhong, WANG Jinliang, WANG Lingyu, WANG Chenchong, XU Wei. Synergistic Effect of Magnetic Field and Grain Size on Martensite Nucleation and Variant Selection. Acta Metall Sin, 2022, 58(12): 1570-1580.
Extrinsic (magnetic fields) and intrinsic (austenite grain sizes) factors can effectively control the martensitic transformation. Until now, research has mainly focused on the separate effects of magnetic fields and austenite grain sizes on the kinetics of the martensitic transformation. Systematic studies considering the coupling effects of magnetic fields and austenite grain sizes on the temperature at which martensite is formed (Ms), the final volume fraction of the transformed martensite, and the kinetics of the martensitic transformation during continuous cooling are still lacking. Furthermore, no study has yet been reported on the mechanism underlying how magnetic fields and austenite grain sizes affect the martensitic transformation. In this study, SUS321 stainless steel is used to investigate the effect of grain size on the kinetics and mechanisms of the martensitic transformation during continuous cooling from 300 K to 4 K under various magnetic fields by using the physical property measurement system (PPMS). The results show that at a constant grain size, the Ms temperature and the final amount of martensite increase as a function of the magnetic field magnitude. Under the same magnetic field, a critical austenite grain size exists, which obviously accelerates the martensitic transformation during cooling. Detailed microstructural characterizations also show that the external magnetic field effectively promotes the formation of ε nucleation sites, which consequently enhances the nucleation rate of α′-martensite and its transformation during further cooling. These findings provide mechanistic insights into the previously found phenomenological results. Additionally, in-depth crystallographic analyses also demonstrate that although the magnetic field promotes ε nucleation, the variant selection during the γ→ε transformation is insensitive to the magnetic field magnitude, unlike the austenite grain size. Under the same magnetic field, the increase in the austenite grain size results in more ε variants during cooling. The collision of similar ε variants restricts the growth of martensite laths and retards the martensitic transformation in coarse-grained austenite. The variant selection of the final transformation ε→α′ is insensitive to the magnetic field magnitude and the austenite grain size.
Fund: National Natural Science Foundation of China(U1808208);National Natural Science Foundation of China(51961130389);National Natural Science Foundation of China(52011530032)
About author: XU Wei, professor, Tel: (024)83680246, E-mail: xuwei@ral.neu.edu.cn
Fig.1 OM images (a, c, e) and statistical results of average grain size (b, d, f) of the 50% cold-rolled sheet treated at different annealing temperatures for 30 min (a, b) 1073 K (c, d) 1173 K (e, f) 1473 K
Fig.2 Variation curves of martensite content under 1 and 9 T magnetic fields of SUS321 stainless steel with different gain sizes during cooling (a) 6.6 μm (b) 29.3 μm (c) 203 μm
Fig.3 EBSD phase maps of microstructure evolution of SUS321 stainless steel with different grain sizes during cooling under 1 T (a, c, e) and 9 T (b, d, f) magnetic fields (a, b) 6.6 μm (c, d) 29.3 μm (e, f) 203 μm
Fig.4 Inverse pole figure (IPF) of ε-martensite in the 29.3 μm austenite grain
Fig.5 Contrast maps by electron channeling contrast imaging (ECCI) of microstructure evolution of SUS321 stainless steel with different grain sizes during cooling under 1 T (a, c, e) and 9 T (b, d, f) magnetic fields (Numbers 1-4 represent ε-martensite variants) (a, b) 6.6 μm (c, d) 29.3 μm (e, f) 203 μm
Fig.6 IPFs and pole figures (insets) of α′-martensite of SUS321 stainless steel with different grain sizes under 1 T (a, c, e) and 9 T (b, d, f) magnetic fields (Numbers 1-6 represent the α′-martensite variants) (a, b) 6.6 μm (c, d) 29.3 μm (e, f) 203 μm
Fig.7 Phase maps and the crystallographic information of grain boundary by EBSD for 29.3 μm samples under 1 T (a) and 9 T (b) magnetic fields (White, cyan, and black colors represent austenite, ε-martensite, and α'-martensite, respectively)
1
Emadoddin E, Akbarzadeh A, Petrov R, et al. Anisotropy of retained austenite stability during transformation to martensite in a TRIP‐assisted steel [J]. Steel Res. Int., 2013, 84: 297
doi: 10.1002/srin.201200197
2
Zhou T P, Wang C Y, Wang C, et al. Austenite stability and deformation-induced transformation mechanism in cold-rolled medium-Mn steel [J]. Mater. Sci. Eng., 2020, A798: 140147
3
De Knijf D, Petrov R, Föjer C, et al. Effect of fresh martensite on the stability of retained austenite in quenching and partitioning steel [J]. Mater. Sci. Eng., 2014, A615: 107
4
Samanta S, Das S, Chakrabarti D, et al. Development of multiphase microstructure with bainite, martensite, and retained austenite in a Co-containing steel through quenching and partitioning (Q&P) treatment [J]. Metall. Mater. Trans., 2013, 44A: 5653
5
Xu H F, Zhao J, Cao W Q, et al. Heat treatment effects on the microstructure and mechanical properties of a medium manganese steel (0.2C-5Mn) [J]. Mater. Sci. Eng., 2012, A532: 435
6
Ren Y Q, Xie Z J, Shang C J. Regulation of retained austenite and its effect on the mechanical properties of low carbon steel [J]. Acta Metall. Sin., 2012, 48: 1074
doi: 10.3724/SP.J.1037.2012.00210
Herrera C, Ponge D, Raabe D. Design of a novel Mn-based 1 GPa duplex stainless TRIP steel with 60% ductility by a reduction of austenite stability [J]. Acta Mater., 2011, 59: 4653
doi: 10.1016/j.actamat.2011.04.011
8
Lee H, Jo M C, Sohn S S, et al. Novel medium-Mn (austenite + martensite) duplex hot-rolled steel achieving 1.6 GPa strength with 20% ductility by Mn-segregation-induced TRIP mechanism [J]. Acta Mater., 2018, 147: 247
doi: 10.1016/j.actamat.2018.01.033
9
Li X, Song R B, Zhou N P, et al. An ultrahigh strength and enhanced ductility cold-rolled medium-Mn steel treated by intercritical annealing [J]. Scr. Mater., 2018, 154: 30
doi: 10.1016/j.scriptamat.2018.05.016
10
Yang F, Zhou J, Han Y, et al. A novel cold-rolled medium Mn steel with an ultra-high product of tensile strength and elongation [J]. Mater. Lett., 2020, 258: 126804
11
Hu J, Cao W Q, Huang C X, et al. Characterization of microstructures and mechanical properties of cold-rolled medium-Mn Steels with different annealing processes [J]. ISIJ Int., 2015, 55: 2229
doi: 10.2355/isijinternational.ISIJINT-2015-187
12
Xie Z J, Shang C J, Zhou W H, et al. Effect of retained austenite on ductility and toughness of a low alloyed multi-phase steel [J]. Acta Metall. Sin., 2016, 52: 224
doi: 10.11900/0412.1961.2015.00280
Chen S, Hu J, Shan L Y, et al. Characteristics of bainitic transformation and its effects on the mechanical properties in quenching and partitioning steels [J]. Mater. Sci. Eng., 2021, A803: 140706
14
Chen S, Wang C C, Shan L Y, et al. Revealing the conditions of bainitic transformation in quenching and partitioning steels [J]. Metall. Mater. Trans., 2019, 50A: 4037
15
Seo E J, Cho L, Estrin Y, et al. Microstructure-mechanical properties relationships for quenching and partitioning (Q&P) processed steel [J]. Acta Mater., 2016, 113: 124
doi: 10.1016/j.actamat.2016.04.048
16
Xu W, Huang M H, Wang J L, et al. Review: Relations between metastable austenite and fatigue behavior of steels [J]. Acta Metall. Sin., 2020, 56: 459
doi: 10.11900/0412.1961.2019.00399
Kakeshita T, Shimizu K, Funada S, et al. Composition dependence of magnetic field-induced martensitic transformations in Fe-Ni alloys [J]. Acta Metall., 1985, 33: 1381
doi: 10.1016/0001-6160(85)90039-2
18
Fukuda T, Kakeshita T, Kindo K. Effect of high magnetic field and uniaxial stress at cryogenic temperatures on phase stability of some austenitic stainless steels [J]. Mater. Sci. Eng., 2006, A438-440: 212
19
Tanhaei S, Gheisari K, Zaree S R A. Effect of cold rolling on the microstructural, magnetic, mechanical, and corrosion properties of AISI 316L austenitic stainless steel [J]. Int. J. Miner. Metall. Mater., 2018, 25: 630
doi: 10.1007/s12613-018-1610-y
20
Shrinivas V, Varma S K, Murr L E. Deformation-induced martensitic characteristics in 304 and 316 stainless steels during room-temperature rolling [J]. Metall. Mater. Trans., 1995, 26A: 661
21
Shi J T, Hou L G, Zuo J R, et al. Quantitative analysis of the martensite transformation and microstructure characterization during cryogenic rolling of a 304 austenitic stainless steel [J]. Acta Metall. Sin., 2016, 52: 945
doi: 10.11900/0412.1961.2015.00635
Wang J L, Wang C C, Huang M H, et al. The effects and mechanisms of pre-deformation with low strain on temperature-induced martensitic transformation [J]. Acta Metall. Sin., 2021, 57: 575
doi: 10.11900/0412.1961.2020.00292
Matsuoka Y, Iwasaki T, Nakada N, et al. Effect of grain size on thermal and mechanical stability of austenite in metastable austenitic stainless steel [J]. ISIJ Int., 2013, 53: 1224
doi: 10.2355/isijinternational.53.1224
24
Brofman P J, Ansell G S. On the effect of fine grain size on the Ms temperature in Fe-27Ni-0.025C alloys [J]. Metall. Trans., 1983, 14A: 1929
25
Koho K, Söderberg O, Lanska N, et al. Effect of the chemical composition to martensitic transformation in Ni-Mn-Ga-Fe alloys [J]. Mater. Sci. Eng., 2004, A378: 384
26
Song C H, Yu H, Li L L, et al. The stability of retained austenite at different locations during straining of I&Q&P steel [J]. Mater. Sci. Eng., 2016, A670: 326
27
Kakeshita T, Saburi T. Effects of magnetic field and hydrostatic pressure on martensitic transformation [J]. Met. Mater., 1997, 3: 87
doi: 10.1007/BF03026130
28
Yang H S, Bhadeshia H K D H. Austenite grain size and the martensite-start temperature [J]. Scr. Mater., 2009, 60: 493
doi: 10.1016/j.scriptamat.2008.11.043
29
Van Bohemen S M C, Morsdorf L. Predicting the Ms temperature of steels with a thermodynamic based model including the effect of the prior austenite grain size [J]. Acta Mater., 2017, 125: 401
doi: 10.1016/j.actamat.2016.12.029
30
Wang J L, Xi X H, Li Y, et al. New insights on nucleation and transformation process in temperature-induced martensitic transformation [J]. Mater. Charact., 2019, 151: 267
doi: 10.1016/j.matchar.2019.03.023
31
Umemoto M, Owen W S. Effects of austenitizing temperature and austenite grain size on the formation of athermal martensite in an iron-nickel and an iron-nickel-carbon alloy [J]. Metall. Mater. Trans., 1974, 5B: 2041
32
Martin D S, van Dijk N H, Brück E, et al. The isothermal martensite formation in a maraging steel: A magnetic study [J]. Mater. Sci. Eng., 2008, A481-482: 757
33
Choi J Y, Fukuda T, Kakeshita T. Effect of magnetic field on successive γ→ε'→α' isothermal martensitic transformation in a SUS304L stainless steel [J]. Mater. Sci. Forum, 2010, 654-656: 130
doi: 10.4028/www.scientific.net/MSF.654-656.130
34
Celada-Casero C, Sietsma J, Santofimia M J. The role of the austenite grain size in the martensitic transformation in low carbon steels [J]. Mater. Des., 2019, 167: 107625
35
Shibata K, Shimozono T, Kohno Y, et al. Effects of heat treatment, pre-strain and magnetic field on the formation of α martensite in Fe-25.5Ni-4Cr and 304L steels [J]. Mater. Trans., JIM, 2000, 41: 893
36
Shimozono T, Kohno Y, Konishi H, et al. Effects of pre-strain, heat treatments and magnetic fields on α' martensite formation in Fe-25.5%Ni-3-5%Cr alloys [J]. Mater. Sci. Eng., 1999, 273-275: 337
doi: 10.1016/S0921-5093(99)00425-6
37
Takaki S, Fukunaga K, Syarif J, et al. Effect of grain refinement on thermal stability of metastable austenitic steel [J]. Mater. Trans., 2004, 45(7): 2245
doi: 10.2320/matertrans.45.2245
38
Xu Z Y. Martensitic transformation [J]. Heat Treat., 1999, (2): 1
徐祖耀. 马氏体相变 [J]. 热处理, 1999, (2): 1
39
Humbert M, Petit B, Bolle B, et al. Analysis of the γ-ɛ-α′ variant selection induced by 10% plastic deformation in 304 stainless steel at -60oC [J]. Mater. Sci. Eng., 2007, A454-455: 508
40
Rodríguez-Martínez J A, Rusinek A, Pesci R, et al. Experimental and numerical analysis of the martensitic transformation in AISI 304 steel sheets subjected to perforation by conical and hemispherical projectiles [J]. Int. J. Solids Struct., 2013, 50: 339
doi: 10.1016/j.ijsolstr.2012.09.019
41
Tian Y, Borgenstam A, Hedström P. Comparing the deformation-induced martensitic transformation with the athermal martensitic transformation in Fe-Cr-Ni alloys [J]. J. Alloys Compd., 2018, 766: 131
doi: 10.1016/j.jallcom.2018.06.326
42
Wu B B, Wang Z Q, Wang X L, et al. Toughening of martensite matrix in high strength low alloy steel: Regulation of variant pairs [J]. Mater. Sci. Eng., 2019, A759: 430
43
Inoue T, Matsuda S, Okamura Y, et al. The fracture of a low carbon tempered martensite [J]. Trans. Jpn. Inst. Met., 1970, 11: 36
doi: 10.2320/matertrans1960.11.36
44
Celada-Casero C, Kwakernaak C, Sietsma J, et al. The influence of the austenite grain size on the microstructural development during quenching and partitioning processing of a low-carbon steel [J]. Mater. Des., 2019, 178: 107847
45
Li, Y, Martín D S, Wang, J L, et al. A review of the thermal stability of metastable austenite in steels: Martensite formation [J]. J. Mater. Sci. Technol., 2021, 91: 200
doi: 10.1016/j.jmst.2021.03.020
46
Liu F, Sommer F, Bos C, et al. Analysis of solid state phase transformation kinetics models and recipes [J]. Int. Mater. Rev., 2007, 52: 193
doi: 10.1179/174328007X160308
47
Lecroisey F, Pineau A. Martensitic transformations induced by plastic deformation in the Fe-Ni-Cr-C system [J]. Metall. Mater. Trans., 1972, 3B: 391
48
Raghavan V, Cohen M. A nucleation model for martensitic transformations in iron-base alloys [J]. Acta Metall., 1972, 20: 333
doi: 10.1016/0001-6160(72)90025-9
49
Morito S, Saito H, Ogawa T, et al. Effect of austenite grain size on the morphology and crystallography of lath martensite in low carbon steels [J]. ISIJ Int., 2005, 45: 91
doi: 10.2355/isijinternational.45.91
