Improving strength may lightweight car bodies by thinning the structure gauge while bearing the same crash loads. Development of the third generation advanced high-strength steels aiming to boost material ductility to over 30% total elongation has become the common sense of potential solutions for stamping. Not only total elongation but also several other parameters, involving presswork hardening, anisotropy ratio, strain rate sensitivity, uniform elongation, edge sensitivity and internal stress between phases, are critical in determining the formability under the complex stress and strain distributions during stamping. We clarify here the logic of formability and difficulties in this context of three types of steel: quenching and partitioning, δ-transformation-induced plasticity and medium Mn-TRIP.
CoomanBCD, KwonOJ, ChinKG.State-of-the-knowledge on TWIP steel. Mater Sci Technol. 2012;28:513–527. doi: 10.1179/1743284711Y.0000000095
2.
SuehiroM, MakiJ, KusumiK, Properties of aluminized steels for hot-forming. 2003 (0148-7191, SAE Technical Paper).
3.
TurettaA, BruschiS, GhiottiA.Investigation of 22MnB5 formability in hot stamping operations. J Mater Process Technol. 2006;177:396–400. doi: 10.1016/j.jmatprotec.2006.04.041
4.
AbdulhayB, BourougaB, DessainC.Experimental and theoretical study of thermal aspects of the hot stamping process. Appl Therm Eng. 2011;31:674–685. doi: 10.1016/j.applthermaleng.2010.11.010
5.
KarbasianH, TekkayaAE.A review on hot stamping. J Mater Process Technol. 2010;210:2103–2118. doi: 10.1016/j.jmatprotec.2010.07.019
6.
GeorgeR, BardelcikA, WorswickM.Hot forming of boron steels using heated and cooled tooling for tailored properties. J Mater Process Technol. 2012;212:2386–2399. doi: 10.1016/j.jmatprotec.2012.06.028
7.
MoriK, OkudaY.Tailor die quenching in hot stamping for producing ultra-high strength steel formed parts having strength distribution. CIRP Ann Manuf Technol. 2010;59:291–294. doi: 10.1016/j.cirp.2010.03.107
8.
YiHL, DuPJ, WangBG.A new invention of press-hardened steel achieving 1880 MPa tensile strength combined with 16% elongation in hot-stamped parts. Proceedings of 5th International Conference on Hot Sheet Metal Forming of High-performance Steel; 2015; Toronto. p. 725–734.
9.
HosfordWF, CaddellRM.Metal forming: mechanics and metallurgy. Cambridge: Cambridge University Press; 2011.
10.
TakahashiM.Development of high strength steels for automobiles. Nippon Steel Technology Report. 2003;88:2–6.
11.
WuX, BahmanpourH, SchmidK.Characterization of mechanically sheared edges of dual phase steels. J Mater Process Technol. 2012;212:1209–1224. doi: 10.1016/j.jmatprotec.2012.01.006
12.
TengZ, ChenX.Edge cracking mechanism in two dual-phase advanced high strength steels. Mater Sci Eng A. 2014;618:645–653. doi: 10.1016/j.msea.2014.06.101
13.
SartkulvanichP, KroenauerB, GolleR, Finite element analysis of the effect of blanked edge quality upon stretch flanging of AHSS. CIRP Ann Manuf Technol. 2010;59:279–282. doi: 10.1016/j.cirp.2010.03.108
14.
ChintamaniJ, SriramS.Sheared edge characterization of steel products used for closure panel applications. 2006 (0148-7191, SAE Technical Paper).
15.
SpeerJ, MatlockD, De CoomanB, Carbon partitioning into austenite after martensite transformation. Acta Mater. 2003;51:2611–2622. doi: 10.1016/S1359-6454(03)00059-4
16.
EdmondsD, HeK, RizzoF, Quenching and partitioning martensite – a novel steel heat treatment. Mater Sci Eng A. 2006;438–440:25–34. doi: 10.1016/j.msea.2006.02.133
17.
SpeerJG, EdmondsDV, RizzoFC, Partitioning of carbon from supersaturated plates of ferrite, with application to steel processing and fundamentals of the bainite transformation. Curr Opin Solid State Mater Sci. 2004;8:219–237. doi: 10.1016/j.cossms.2004.09.003
18.
ClarkeA, SpeerJ, MillerM, Carbon partitioning to austenite from martensite or bainite during the quench and partition (Q&P) process: a critical assessment. Acta Mater. 2008;56:16–22. doi: 10.1016/j.actamat.2007.08.051
19.
EdmondsD, SpeerJ.Martensitic steels with carbide free microstructures containing retained austenite. Mater Sci Technol. 2010;26:386–391. doi: 10.1179/026708309X12512744154162
20.
SomaniMC, PorterD, KarjalainenL, On various aspects of decomposition of austenite in a high-silicon steel during quenching and partitioning. Metall Mater Trans A. 2014;45:1247–1257. doi: 10.1007/s11661-013-2053-8
21.
GaoG, ZhangH, GuiX, Enhanced ductility and toughness in an ultrahigh-strength Mn–Si–Cr–C steel: the great potential of ultrafine filmy retained austenite. Acta Mater. 2014;76:425–433. doi: 10.1016/j.actamat.2014.05.055
22.
ZhangJ, DingH, MisraRDK.Enhanced strain hardening and microstructural characterization in a low carbon quenching and partitioning steel with partial austenization. Mater Sci Eng A. 2015;636:53–59. doi: 10.1016/j.msea.2015.03.095
23.
SunJ, YuH, WangS, Study of microstructural evolution, microstructure-mechanical properties correlation and collaborative deformation-transformation behavior of quenching and partitioning (Q&P) steel. Mater Sci Eng A. 2014;596:89–97. doi: 10.1016/j.msea.2013.12.054
24.
MandalG, GhoshSK, BeraS, Effect of partial and full austenitisation on microstructure and mechanical properties of quenching and partitioning steel. Mater Sci Eng A. 2016;676:56–64. doi: 10.1016/j.msea.2016.08.094
25.
SunJ, YuH.Microstructure development and mechanical properties of quenching and partitioning (Q&P) steel and an incorporation of hot-dipping galvanization during Q&P process. Mater Sci Eng A. 2013;586:100–107. doi: 10.1016/j.msea.2013.08.021
26.
YanS, LiuX, LiuWJ, Comparative study on microstructure and mechanical properties of a C–Mn–Si steel treated by quenching and partitioning (Q&P) processes after a full and intercritical austenitization. Mater Sci Eng A. 2017;684:261–269. doi: 10.1016/j.msea.2016.12.026
27.
LiuR, SunL, WangX, Strain rate effect on forming limit diagram for advanced high strength steels. SAE Int J Mater Manuf. 2014;7:583–587. doi: 10.4271/2014-01-0993
28.
WuR, LiW, ZhouS, Effect of retained austenite on the fracture toughness of quenching and partitioning (Q&P)-treated sheet steels. Metall Mater Trans A. 2014;45:1892–1902. doi: 10.1007/s11661-013-2113-0
29.
SongC, YuH, LiL, The stability of retained austenite at different locations during straining of I&Q&P steel. Mater Sci Eng A. 2016;670:326–334. doi: 10.1016/j.msea.2016.06.044
30.
XiongXC, SunL, WangJF, Properties assessment of the first industrial coils of low-density duplex δ-TRIP steel. Mater Sci Technol. 2016;32:1403–1408. doi: 10.1080/02670836.2015.1130364
31.
YiHL.Review on δ-transformation-induced plasticity (TRIP) steels with low density: the concept and current progress. JOM. 2014;66:1759–1769. doi: 10.1007/s11837-014-1089-6
32.
YiHL, ChenP, BhadeshiaHKDH.Optimizing the morphology and stability of retained austenite in a δ-TRIP steel. Metall Mater Trans A. 2014;45:3512–3518. doi: 10.1007/s11661-014-2267-4
33.
YiHL, ChenP, HouZY, A novel design: partitioning achieved by quenching and tempering (Q–T & P) in an aluminium-added low-density steel. Scr Mater. 2013;68:370–374. doi: 10.1016/j.scriptamat.2012.10.018
34.
YiHL, LeeKY, BhadeshiaHKDH.Extraordinary ductility in Al-bearing – TRIP steel. Proc R Soc A Math Phys Eng Sci. 2011;467:234–243.
35.
YiHL, LeeKY, BhadeshiaHKDH.Mechanical stabilisation of retained austenite in δ-TRIP steel. Mater Sci Eng A. 2011;528:5900–5903. doi: 10.1016/j.msea.2011.03.111
36.
ChenP, WangGD, XiongXC, Abnormal expansion due to pearlite-to-austenite transformation in high aluminium-added steels. Mater Sci Technol. 2016;32:1678–1682. doi: 10.1080/02670836.2015.1138046
37.
ChenP, XiongXC, WangGD, The origin of the brittleness of high aluminum pearlite and the method for improving ductility. Scr Mater. 2016;124:42–46. doi: 10.1016/j.scriptamat.2016.06.031
38.
YiHL, LeeKY, BhadeshiaHKDH.Stabilisation of ferrite in hot rolled δ-TRIP steel. Mater Sci Technol. 2011;27:525–529. doi: 10.1179/026708309X12506934374001
39.
LuoH, ShiJ, WangC, Experimental and numerical analysis on formation of stable austenite during the intercritical annealing of 5Mn steel. Acta Mater. 2011;59:4002–4014. doi: 10.1016/j.actamat.2011.03.025
40.
CaoWQ, WangC, ShiJ, Microstructure and mechanical properties of Fe–0.2C–5Mn steel processed by ART-annealing. Mater Sci Eng A. 2011;528:6661–6666. doi: 10.1016/j.msea.2011.05.039
41.
MerwinMJ.Low-carbon manganese TRIP steels. Mater Sci Forum. 2007;539–543:4327–4332. doi: 10.4028/www.scientific.net/MSF.539-543.4327
42.
WangC, CaoW, ShiJ, Deformation microstructures and strengthening mechanisms of an ultrafine grained duplex medium-Mn steel. Mater Sci Eng A. 2013;562:89–95. doi: 10.1016/j.msea.2012.11.044
43.
TsuchiyamaT, InoueT, TobataJ, Microstructure and mechanical properties of a medium manganese steel treated with interrupted quenching and intercritical annealing. Scr Mater. 2016;122:36–39. doi: 10.1016/j.scriptamat.2016.05.019
44.
LeeS, De CoomanBC.Tensile behavior of intercritically annealed ultra-fine grained 8% Mn multi-phase steel. Steel Res Int. 2015;86:1170–1178. doi: 10.1002/srin.201500038
45.
SuhD-W, ParkS-J, LeeT-H, Influence of Al on the microstructural evolution and mechanical behavior of low-carbon, manganese transformation-induced-plasticity steel. Metall Mater Trans A. 2010;41:397–408. doi: 10.1007/s11661-009-0124-7
46.
GibbsPJ, De MoorE, MerwinMJ, Austenite stability effects on tensile behavior of manganese-enriched-austenite transformation-induced plasticity steel. Metall Mater Trans A. 2011;42:3691–3702. doi: 10.1007/s11661-011-0687-y
47.
LeeS-J, LeeS, De CoomanBC.Mn partitioning during the intercritical annealing of ultrafine-grained 6% Mn transformation-induced plasticity steel. Scr Mater. 2011;64:649–652. doi: 10.1016/j.scriptamat.2010.12.012
48.
HuJ, CaoW, HuangC, Characterization of microstructures and mechanical properties of cold-rolled medium-Mn steels with different annealing processes. ISIJ Int. 2015;55:2229–2236. doi: 10.2355/isijinternational.ISIJINT-2015-187
49.
SuhDW, RyuJH, JooMS, Medium-alloy manganese-rich transformation-induced plasticity steels. Metall Mater Trans A. 2013;44:286–293. doi: 10.1007/s11661-012-1402-3
50.
WangXG, WangL, HuangMX.Kinematic and thermal characteristics of Lüders and Portevin-Le Châtelier bands in a medium Mn transformation-induced plasticity steel. Acta Mater. 2017;124:17–29. doi: 10.1016/j.actamat.2016.10.069
51.
LuoH, DongH, HuangM.Effect of intercritical annealing on the Lüders strains of medium Mn transformation-induced plasticity steels. Mater Des. 2015;83:42–48. doi: 10.1016/j.matdes.2015.05.085
52.
HanJ, LeeS-J, JungJ-G, The effects of the initial martensite microstructure on the microstructure and tensile properties of intercritically annealed Fe–9Mn–0.05C steel. Acta Mater. 2014;78:369–377. doi: 10.1016/j.actamat.2014.07.005
53.
LeeS, LeeS-J, De CoomanBC.Work hardening behavior of ultrafine-grained Mn transformation-induced plasticity steel. Acta Mater. 2011;59:7546–7553. doi: 10.1016/j.actamat.2011.08.030
54.
LeeS, LeeS-J, Santhosh KumarS, Localized deformation in multiphase, ultra-fine-grained 6 Pct Mn transformation-induced plasticity steel. Metall Mater Trans A. 2011;42:3638–3651. doi: 10.1007/s11661-011-0636-9
55.
RyuJH, KimJI, KimHS, Austenite stability and heterogeneous deformation in fine-grained transformation-induced plasticity-assisted steel. Scr Mater. 2013;68:933–936. doi: 10.1016/j.scriptamat.2013.02.026
