Research Progress of Microstructure Control and Strengthening Mechanism of QPT Process Advanced Steel with High Strength and Toughness
LI Wei(), JIA Xingqi, JIN Xuejun
Institute of Phase Transformation and Structure, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Cite this article:
LI Wei, JIA Xingqi, JIN Xuejun. Research Progress of Microstructure Control and Strengthening Mechanism of QPT Process Advanced Steel with High Strength and Toughness. Acta Metall Sin, 2022, 58(4): 444-456.
Advanced high-strength steels have undergone rapid development from the first to third generation, which has considerably contributed to the continuous improvement of lightweight materials and safety in the automotive industry. The third generation representative steels, including quenching-partitioning (QP) and quenching-partitioning-tempering (QPT) steels have rapidly developed in the past 10 years. This article summarizes the preparation process as well as the strengthening and toughening mechanisms of QP and QPT steels from the following perspectives: (1) process design development and principles from QP to QPT, (2) carbon distribution and microstructure evolution during the partitioning process, (3) stability of metastable austenite and its influence on transformation-induced plasticity, (4) microstructure and heat-treatment process design of nanoprecipitation-strengthened QPT steel, (5) the integrated process of hot-forming QPT steel, and (6) the strengthening and toughening mechanisms and the service performance of QP and QPT steels. Finally, future prospects for manufacturing and using QP and QPT steels are discussed.
Fund: National Natural Science Foundation of China(52071209);National Natural Science Foundation of China(51831002);National Key Research and Development Program of China(2017YFB0703003)
About author: LI Wei, associate professor, Tel: (021)54745567, E-mail: weilee@sjtu.edu.cn
Fig.1 Schematic of quenching-partitioning (QP) heat treatment and corresponding microstructures (Ms—martensite transformation-start temperature, Mf—martensite transformation-finish temperature)
Fig.2 Schematics of QP heat treatment for medium manganese steel and corresponding microstructures (As—austenite transformation-start temperature)
Fig.3 TEM image (a, c) and EDS analyses (b, d) showing evidence of the distribution of Mn across the austenite/ferrite interfaces in the HR-QPT (a, b) and CR-QPT (c, d) steel[54] (QPT—quenching-partitioning-tempering, HR—hot rolling, CR—cool rolling)
Fig.4 TEM-EDS characterization of the core-shell structure austenite with Mn concentration gradient obtained by tempering and double partitioning (TDP) (a) and double partitioning (DP) (b) processes; 3D atom probe characterization of austenite/ferrite interface (c) and precipitation phase (d)[63]
Fig.5 Schematics of the application of non-isothermal partitioning process to hot forming high-strength steel (Ac3—fully austenitizing temperature, α—fresh martensite)
1
Lu K. The future of metals [J]. Science, 2010, 328: 319
2
Ma M T, Yi H L, Lu H Z, et al. On the lightweighting of automobile [J]. Eng. Sci., 2009, 11(9): 20
Speer J G, Streicher A M, Matlock D K, et al. Austenite Formation and Decomposition [M]. Warrendale, PA: TMS, 2003: 505
4
Speer J G, De Moor E, Findley K O, et al. Analysis of microstructure evolution in quenching and partitioning automotive sheet steel [J]. Metall. Mater. Trans., 2011, 42A: 3591
5
Speer J, Matlock D K, De Cooman B C, et al. Carbon partitioning into austenite after martensite transformation [J]. Acta Mater., 2003, 51: 2611
6
Sakuma Y, Matsumura O, Takechi H. Mechanical properties and retained austenite in intercritically heat-treated bainite-transformed steel and their variation with Si and Mn additions [J]. Metall. Trans., 1991, 22A: 489
7
Kim S J, Lee C G, Choi I, et al. Effects of heat treatment and alloying elements on the microstructures and mechanical properties of 0.5 wt pct C transformation-induced plasticity-aided cold-rolled steel sheets [J]. Metall. Mater. Trans., 2001, 32A: 505
8
Matsumura O, Sakuma Y, Takechi H. Enhancement of elongation by retained austenite in intercritical annealed 0.4C-1.5Si-0.8Mn steel [J]. Trans. Iron Steel Inst. Jpn, 1987, 27: 570
9
Matsumura O, Sakuma Y, Takechi H. Trip and its kinetic aspects in austempered 0.4C-1.5Si-0.8Mn steel [J]. Scr. Metall., 1987, 21: 1301
10
Matlock D K, Speer J G. Design considerations for the next generation of advanced high strength sheet steels [A]. Proceedings of the 3rd International Conference on Advanced Structural Steels (ICASS) [C]. Seoul, South Korea: Korean Institute of Metals and Materials, 2006: 774
11
Liu L, He B B, Cheng G J, et al. Optimum properties of quenching and partitioning steels achieved by balancing fraction and stability of retained austenite [J]. Scr. Mater., 2018, 150: 1
12
Allain S Y P, Gaudez S, Geandier G, et al. Internal stresses and carbon enrichment in austenite of quenching and partitioning steels from high energy X-ray diffraction experiments [J]. Mater. Sci. Eng., 2018, A710: 245
13
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
14
Toji Y, Miyamoto G, Raabe D. Carbon partitioning during quenching and partitioning heat treatment accompanied by carbide precipitation [J]. Acta Mater., 2015, 86: 137
15
Hsu T Y, Xu Z Y. Design of structure, composition and heat treatment process for high strength steel [J]. Mater. Sci. Forum, 2007, 561-565: 2283
16
Hsu T Y. Quenching-partitioning-tempering process for ultra-high strength steel [J]. Int. Heat Treat. Surf. Eng., 2008, 2: 64
17
Hsu T Y, Jin X J. Ultra-high strength steel treated by using quenching-partitioning-tempering process [A]. Advanced Steels [M]. Berlin, Heidelberg: Springer, 2011: 67
18
Hsu T Y, Jin X J, Rong Y H. Strengthening and toughening mechanisms of quenching-partitioning-tempering (Q-P-T) steels [J]. J. Alloys Compd., 2013, 577: S568
19
Miller R L. Ultrafine-grained microstructures and mechanical properties of alloy steels [J]. Metall. Mater. Trans., 1972, 3B: 905
20
Lee Y K, Han J. Current opinion in medium manganese steel [J]. Mater. Sci. Technol., 2015, 31: 843
21
De Cooman B C. High Mn TWIP steel and medium Mn steel [A]. Automotive Steels [M]. Design: Woodhead Publishing, 2017: 317
22
Luo H W, Shi J, Wang C, et al. Experimental and numerical analysis on formation of stable austenite during the intercritical annealing of 5Mn steel [J]. Acta Mater., 2011, 59: 4002
23
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
24
Aydin H, Jung I H, Essadiqi E, et al. Twinning and tripping in 10% Mn steels [J]. Mater. Sci. Eng., 2014, A591: 90
25
Lee S, Woo W, De Cooman B C. Analysis of the plasticity-enhancing mechanisms in 12 pctMn austeno-ferritic steel by in situ neutron diffraction [J]. Metall. Mater. Trans., 2014, 45A: 5823
26
Lee S, Lee K, De Cooman B C. Observation of the TWIP + TRIP plasticity-enhancement mechanism in Al-added 6 Wt Pct medium Mn steel [J]. Metall. Mater. Trans., 2015, 46A: 2356
27
Sohn S S, Choi K, Kwak J H, et al. Novel ferrite-austenite duplex lightweight steel with 77% ductility by transformation induced plasticity and twinning induced plasticity mechanisms [J]. Acta Mater., 2014, 78: 181
28
Matas S, Hehemann R F. Retained austenite and the tempering of martensite [J]. Nature, 1960, 187: 685
29
Wang S B, Kistanov A A, King G, et al. In-situ quantification and density functional theory elucidation of phase transformation in carbon steel during quenching and partitioning [J]. Acta Mater., 2021, 221: 117361
30
Morsdorf L, Emelina E, Gault B, et al. Carbon redistribution in quenched and tempered lath martensite [J]. Acta Mater., 2021, 205: 116521
31
Dai Z B, Ding R, Yang Z G, et al. Elucidating the effect of Mn partitioning on interface migration and carbon partitioning during Quenching and Partitioning of the Fe-C-Mn-Si steels: Modeling and experiments [J]. Acta Mater., 2018, 144: 666
32
Zhang J Z, Dai Z B, Zeng L Y, et al. Revealing carbide precipitation effects and their mechanisms during quenching-partitioning-tempering of a high carbon steel: Experiments and modeling [J]. Acta Mater., 2021, 217: 117176
33
Kickinger C, Suppan C, Hebesberger T, et al. Microstructure and mechanical properties of partially ferritic Q&P steels [J]. Mater. Sci. Eng., 2021, A815: 141296
34
Lu H H, Guo H K, Zhang W G, et al. Improving the mechanical properties of the ASIS 430 stainless steels by using Q&P and Q&T processes [J]. Mater. Lett., 2019, 240: 275
35
Zheng H, Hu F, Zhou W, et al. Influence of intercritical heating on the microstructure and mechanical properties of al‐rich quenching-partitioning-tempering steel [J]. Steel Res. Int., 2019, 90: 1900198
36
Wang J J, Van Der Zwaag S. Stabilization mechanisms of retained austenite in transformation-induced plasticity steel [J]. Metall. Mater. Trans., 2001, 32A: 1527
37
Li Z C, Ding H, Misra R D K, et al. Microstructural evolution and deformation behavior in the Fe-(6, 8.5)Mn-3Al-0.2C TRIP steels [J]. Mater. Sci. Eng., 2016, A672: 161
38
Huang H, Matsumura O, Furukawa T. Retained austenite in low carbon, manganese steel after intercritical heat treatment [J]. Mater. Sci. Technol., 1994, 10: 621
39
Maheswari N, Amirthalingam M, Schwedt A, et al. Temperature dependent partitioning mechanisms and its associated microstructural evolution in a CMnSiAl quenching and partitioning (Q&P) steel [J]. Mater. Today Commun., 2021, 29: 102918
40
Ghosh G, Olson G B. Kinetics of F.C.C. → B.C.C. heterogeneous martensitic nucleation—I. The critical driving force for athermal nucleation [J]. Acta Metall. Mater., 1994, 42: 3361
41
Wang M M, Tasan C C, Ponge D, et al. Smaller is less stable: Size effects on twinning vs. transformation of reverted austenite in TRIP-maraging steels [J]. Acta Mater., 2014, 79: 268
42
Tsuji N, Maki T. Enhanced structural refinement by combining phase transformation and plastic deformation in steels [J]. Scr. Mater., 2009, 60: 1044
43
Xiong X C, Chen B, Huang M X, et al. The effect of morphology on the stability of retained austenite in a quenched and partitioned steel [J]. Scr. Mater., 2013, 68: 321
44
Min J Y, Hector Jr L G, Zhang L, et al. Elevated-temperature mechanical stability and transformation behavior of retained austenite in a quenching and partitioning steel [J]. Mater. Sci. Eng., 2016, A673: 423
45
Tirumalasetty G K, van Huis M A, Kwakernaak C, et al. Deformation-induced austenite grain rotation and transformation in TRIP-assisted steel [J]. Acta Mater., 2012, 60: 1311
46
Zhang S, Findley K O. Quantitative assessment of the effects of microstructure on the stability of retained austenite in TRIP steels [J]. Acta Mater., 2013, 61: 1895
47
Ebner S, Schnitzer R, Maawad E, et al. Influence of partitioning parameters on the mechanical stability of austenite in a Q&P steel: A comparative in-situ study [J]. Materialia, 2021, 15: 101033
48
Curtze S, Kuokkala V T, Hokka M, et al. Deformation behavior of TRIP and DP steels in tension at different temperatures over a wide range of strain rates [J]. Mater. Sci. Eng., 2009, A507: 124
49
Curtze S, Kuokkala V T. Dependence of tensile deformation behavior of TWIP steels on stacking fault energy, temperature and strain rate [J]. Acta Mater., 2010, 58: 5129
50
van der Wegen G J L, Bronsveld P M, de Hosson J T M. A comparison between different theories predicting the stacking fault energy from extended nodes [J]. Scr. Metall., 1980, 14: 285
51
Allain S, Chateau J P, Bouaziz O. A physical model of the twinning-induced plasticity effect in a high manganese austenitic steel [J]. Mater. Sci. Eng., 2004, A387-389: 143
52
da Silva A K, Inden G, Kumar A, et al. Competition between formation of carbides and reversed austenite during tempering of a medium-manganese steel studied by thermodynamic-kinetic simulations and atom probe tomography [J]. Acta Mater., 2018, 147: 165
53
Kuzmina M, Herbig M, Ponge D, et al. Linear complexions: Confined chemical and structural states at dislocations [J]. Science, 2015, 349: 1080
54
Li Y, Li W, Min N, et al. Effects of hot/cold deformation on the microstructures and mechanical properties of ultra-low carbon medium manganese quenching-partitioning-tempering steels [J]. Acta Mater., 2017, 139: 96
55
Li Y, Li W, Liu W Q, et al. The austenite reversion and co-precipitation behavior of an ultra-low carbon medium manganese quenching-partitioning-tempering steel [J]. Acta Mater., 2018, 146: 126
56
Dmitrieva O, Ponge D, Inden G, et al. Chemical gradients across phase boundaries between martensite and austenite in steel studied by atom probe tomography and simulation [J]. Acta Mater., 2011, 59: 364
57
Kuzmina M, Ponge D, Raabe D. Grain boundary segregation engineering and austenite reversion turn embrittlement into toughness: Example of a 9 wt.% medium Mn steel [J]. Acta Mater., 2015, 86: 182
58
Chen H, Gamsjäger E, Schider S, et al. In situ observation of austenite-ferrite interface migration in a lean Mn steel during cyclic partial phase transformations [J]. Acta Mater., 2013, 61: 2414
59
Jin H, Elfimov I, Militzer M. Study of the interaction of solutes with Σ5 (013) tilt grain boundaries in iron using density-functional theory [J]. J. Appl. Phys., 2014, 115: 093506
60
Wang M M, Tasan C C, Ponge D, et al. Nanolaminate transformation-induced plasticity—twinning-induced plasticity steel with dynamic strain partitioning and enhanced damage resistance [J]. Acta Mater., 2015, 85: 216
61
Han J, da Silva A K, Ponge D, et al. The effects of prior austenite grain boundaries and microstructural morphology on the impact toughness of intercritically annealed medium Mn steel [J]. Acta Mater., 2017, 122: 199
62
Raabe D, Sandlöbes S, Millán J, et al. Segregation engineering enables nanoscale martensite to austenite phase transformation at grain boundaries: A pathway to ductile martensite [J]. Acta Mater., 2013, 61: 6132
63
Li Y, Li W, Min N, et al. Mechanical response of a medium manganese steel with encapsulated austenite [J]. Scr. Mater., 2020, 178: 211
64
Hu B, Luo H W. A novel two-step intercritical annealing process to improve mechanical properties of medium Mn steel [J]. Acta Mater., 2019, 176: 250
65
Xu Y T, Li W, Du H, et al. Tailoring the metastable reversed austenite from metastable Mn-rich carbides [J]. Acta Mater., 2021, 214: 116986
66
Santofimia M J, Speer J G, Clarke A J, et al. Influence of interface mobility on the evolution of austenite-martensite grain assemblies during annealing [J]. Acta Mater., 2009, 57: 4548
67
Dai Z B, Ding R, Yang Z G, et al. Thermo-kinetic design of retained austenite in advanced high strength steels [J]. Acta Mater., 2018, 152: 288
68
Jin X J, Gong Y, Han X H, et al. A review of current state and prospect of the manufacturing and application of advanced hot stamping automobile steels [J]. Acta Metall. Sin., 2020, 56: 411
Shi Z M, Liu K, Wang M Q, et al. Effect of non-isothermal deformation of austenite on phase transformation and microstructure of 22SiMn2TiB steel [J]. Mater. Sci. Eng., 2012, A535: 290
70
Winter S, Werner M, Haase R, et al. Processing Q&P steels by hot-metal gas forming: Influence of local cooling rates on the properties and microstructure of a 3rd generation AHSS [J]. J. Mater. Process. Technol., 2021, 293: 117070
71
Xu Y S, Gong Y, Du H, et al. A newly-designed hot stamping plus non-isothermal Q&P process to improve mechanical properties of commercial QP980 steel [J]. Int. J. Lightweight Mater. Manuf., 2020, 3: 26
72
Pineau A G, Pelloux R M. Influence of strain-induced martensitic transformations on fatigue crack growth rates in stainless steels [J]. Metall. Mater. Trans., 1974, 5B: 1103
73
Ritchie R O, Suresh S. Some considerations on fatigue crack closure at near-threshold stress intensities due to fracture surface morphology [J]. Metall. Trans., 1982, 13A: 937
74
Stringfellow R G. Mechanics of strain-induced transformation toughening in metastable austenitic steels [D]. Cambridge: Massachusetts Institute of Technology, 1990: 516
75
Leal R H. Transformation toughening of metastable austenitic steels [D]. Cambridge: Massachusetts Institute of Technology, 1984
76
Wu R M. Study on the relationship between toughness and microstructural evolution of quenching & partitioning (Q&P) treated high-strength sheet steel [D]. Shanghai: Shanghai Jiao Tong University, 2015
Gao G H, Gao B, Gui X L, et al. Correlation between microstructure and yield strength of as-quenched and Q&P steels with different carbon content (0.06-0.42 wt%C) [J]. Mater. Sci. Eng., 2019, A753: 1
78
Hockauf K, Wagner M F X, Mašek B, et al. Mechanisms of fatigue crack propagation in a Q&P-processed steel [J]. Mater. Sci. Eng., 2019, A754: 18
79
Calcagnotto M, Ponge D, Raabe D. Effect of grain refinement to 1 μm on strength and toughness of dual-phase steels [J]. Mater. Sci. Eng., 2010, A527: 7832
80
Calcagnotto M, Adachi Y, Ponge D, et al. Deformation and fracture mechanisms in fine-and ultrafine-grained ferrite/martensite dual-phase steels and the effect of aging [J]. Acta Mater., 2011, 59: 658
81
Cao W Q, Zhang M D, Huang C X, et al. Ultrahigh Charpy impact toughness (~ 450 J) achieved in high strength ferrite/martensite laminated steels [J]. Sci. Rep., 2017, 7: 41459
82
Cepeda-Jiménez C M, García-Infanta J M, Pozuelo M, et al. Impact toughness improvement of high-strength aluminium alloy by intrinsic and extrinsic fracture mechanisms via hot roll bonding [J]. Scr. Mater., 2009, 61: 407
83
Pozuelo M, Carreño F, Ruano O A. Delamination effect on the impact toughness of an ultrahigh carbon-mild steel laminate composite [J]. Compos. Sci. Technol., 2006, 66: 2671
84
Kimura Y, Inoue T, Yin F X, et al. Inverse temperature dependence of toughness in an ultrafine grain-structure steel [J]. Science, 2008, 320: 1057
85
Koyama M, Zhang Z, Wang M M, et al. Bone-like crack resistance in hierarchical metastable nanolaminate steels [J]. Science, 2017, 355: 1055
86
Liu L, Yu Q, Wang Z, et al. Making ultrastrong steel tough by grain-boundary delamination [J]. Science, 2020, 368: 1347
87
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
88
Xia P, Vercruysse F, Celada-Casero C, et al. Effect of alloying and microstructure on formability of advanced high-strength steels processed via quenching and partitioning [J]. Mater. Sci. Eng., 2022, A831: 142217
89
Zhang J Z, Cui Y G, Zuo X W, et al. Dislocations across interphase enable plain steel with high strength-ductility [J]. Sci. Bull., 2021, 66: 1058
90
Baker L J, Daniel S R, Parker J D. Metallurgy and processing of ultralow carbon bake hardening steels [J]. Mater. Sci. Technol., 2002, 18: 355
91
Zhao J Z, De A K, De Cooman B C. Formation of the Cottrell atmosphere during strain aging of bake-hardenable steels [J]. Metall. Mater. Trans., 2001, 32A: 417
92
De Cooman B C. Structure-properties relationship in TRIP steels containing carbide-free bainite [J]. Curr. Opin. Solid State Mater. Sci., 2004, 8: 285
93
Zhu X, Li W, Hsu T Y, et al. Improved resistance to hydrogen embrittlement in a high-strength steel by quenching-partitioning-tempering treatment [J]. Scr. Mater., 2015, 97: 21
94
Szost B A, Vegter R H, Rivera-Díaz-del-Castillo P E J. Hydrogen-trapping mechanisms in nanostructured steels [J]. Metall. Mater. Trans., 2013, 44A: 4542
95
Zhang S Q, Huang Y H, Sun B T, et al. Effect of Nb on hydrogen-induced delayed fracture in high strength hot stamping steels [J]. Mater. Sci. Eng., 2015, A626: 136
96
Nagao A, Hayashi K, Oi K, et al. Effect of uniform distribution of fine cementite on hydrogen embrittlement of low carbon martensitic steel plates [J]. ISIJ Int., 2012, 52: 213
97
Bhadeshia H K D H. Prevention of hydrogen embrittlement in steels [J]. ISIJ Int., 2016, 56: 24
98
Zhu X, Li W, Zhao H S, et al. Unveiling the origin of work hardening behavior in an ultrafine-grained manganese transformation-induced plasticity steel by hydrogen investigation [J]. Metall. Mater. Trans., 2016, 47A: 4362
99
Lu H Z, Zhao Y, Feng Y, et al. Progress and prospect for development and application of microalloying press-hardening steel [J]. Mater. Mech. Eng., 2020, 44(12): 1
