An aluminium-containing medium manganese steel has been designed to undergo intercritical annealing followed by quenching in water and subsequent partitioning. Water quenching, replacing the quenching temperature (QT) between 150 and 300°C in conventional quenching and partitioning steels, is therefore adopted in QP alloys, in order to guarantee the precise QT in practice. The low intercritical annealing temperature of 750°C refines both ferrite and prior austenite grains into submicron size. The large fraction of ultra-fine ferrite, as well as the transformation-induced plasticity effect of retained austenite, improves the overall ductility of this water-quenched and partitioned steel. The alloy has achieved excellent mechanical properties of 1130 MPa ultimate tensile strength combined with 19.2% total elongation.
SpeerJ, MatlockDK, De CoomanBC, Carbon partitioning into austenite after martensite transformation. Acta Mater. 2003;51(9):2611–2622. doi: 10.1016/S1359-6454(03)00059-4
2.
EdmondsDV, HeK, RizzoFC, Quenching and partitioning martensite – a novel steel heat treatment. Mater Sci Eng A. 2006: 25–34: 438–440.
3.
EdmondsDV, SpeerJG.Martensitic steels with carbide free microstructures containing retained austenite. Mater Sci Technol. 2013;26(4):386–391. doi: 10.1179/026708309X12512744154162
4.
BartlettLN, Van AkenDC, MedvedevaJ, An atom probe study of kappa carbide precipitation and the effect of silicon addition. Metall Mater Trans A. 2014;45(5):2421–2435. doi: 10.1007/s11661-014-2187-3
5.
TojiY, MatsudaH, RaabeD.Effect of Si on the acceleration of bainite transformation by pre-existing martensite. Acta Mater. 2016;116:250–262. doi: 10.1016/j.actamat.2016.06.044
6.
ClarkeAJ, SpeerJG, MillerMK, Carbon partitioning to austenite from martensite or bainite during the quench and partition (Q&P) process: a critical assessment. Acta Mater. 2008;56(1):16–22. doi: 10.1016/j.actamat.2007.08.051
7.
KimB, SietsmaJ, SantofimiaMJ.The role of silicon in carbon partitioning processes in martensite/austenite microstructures. Mater Des. 2017;127:336–345. doi: 10.1016/j.matdes.2017.04.080
8.
ClarkeAJ, SpeerJG, MatlockDK, Influence of carbon partitioning kinetics on final austenite fraction during quenching and partitioning. Scr Mater. 2009;61(2):149–152. doi: 10.1016/j.scriptamat.2009.03.021
9.
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(6):370–374. doi: 10.1016/j.scriptamat.2012.10.018
10.
SeoEJ, ChoL, De CoomanBC.Application of quenching and partitioning processing to medium Mn steel. Metall Mater Trans A. 2015;46(1):27–31. doi: 10.1007/s11661-014-2657-7
11.
De MoorE, SpeerJG, MatlockDK, Quenching and partitioning of CMnSi steels containing elevated manganese levels. Steel Res Int. 2012;83(4):322–327. doi: 10.1002/srin.201100318
12.
LuoH, ShiJ, WangC, Experimental and numerical analysis on formation of stable austenite during the intercritical annealing of 5Mn steel. Acta Mater. 2011;59(10):4002–4014. doi: 10.1016/j.actamat.2011.03.025
13.
ChangY, WangCY, ZhaoKM, An introduction to medium-Mn steel: metallurgy, mechanical properties and warm stamping process. Mater Des. 2016;94:424–432. doi: 10.1016/j.matdes.2016.01.048
14.
HanQ, KangY, ZhaoX, Suppression of Ms temperature by carbon partitioning from carbon-supersaturated ferrite to metastable austenite during intercritical annealing. Mater Des. 2013;51:409–414. doi: 10.1016/j.matdes.2013.04.055
15.
KoistinenREMDP.A general equation prescribing the extent of the austenite–martensite transformation in pure iron–carbon alloys and plain carbon steels. Acta Metall. 1959;7:59–60. doi: 10.1016/0001-6160(59)90170-1
16.
SugimotoKI, UsuiN, KobayashiM, Effects of Volume Fraction and Stability of Retained Austenite on Ductility of TRIP-aided Dual-phase Steels. ISIJ International. 1992;32(12):1311–1318. doi: 10.2355/isijinternational.32.1311
17.
SantofimiaMJ, Nguyen-MinhT, ZhaoL, New low carbon Q&P steels containing film-like intercritical ferrite. Mater Sci Eng A. 2010;527(23):6429–6439. doi: 10.1016/j.msea.2010.06.083
18.
SodjitS, UthaisangsukV.Microstructure based prediction of strain hardening behavior of dual phase steels. Mater Des. 2012;41:370–379. doi: 10.1016/j.matdes.2012.05.010
19.
MazaheriY, KermanpurA, NajafizadehA, Effects of initial microstructure and thermomechanical processing parameters on microstructures and mechanical properties of ultrafine grained dual phase steels. Mater Sci Eng A. 2014;612:54–62. doi: 10.1016/j.msea.2014.06.031
20.
SchemmannL, ZaeffererS, RaabeD, Alloying effects on microstructure formation of dual phase steels. Acta Mater. 2015;95:386–398. doi: 10.1016/j.actamat.2015.05.005
21.
SeoEJ, ChoL, De CoomanBC.Application of quenching and partitioning (Q&P) processing to press hardening steel. Metall Mater Trans A. 2014;45(9):4022–4037. doi: 10.1007/s11661-014-2316-z
22.
XiongXC, ChenB, HuangMX, The effect of morphology on the stability of retained austenite in a quenched and partitioned steel. Scr Mater. 2013;68(5):321–324. doi: 10.1016/j.scriptamat.2012.11.003
23.
HajyAkbaryF, SietsmaJ, MiyamotoG, Interaction of carbon partitioning, carbide precipitation and bainite formation during the Q&P process in a low C steel. Acta Mater. 2016;104:72–83. doi: 10.1016/j.actamat.2015.11.032
24.
De KnijfD, PetrovR, FöjerC, Effect of fresh martensite on the stability of retained austenite in quenching and partitioning steel. Mater Sci Eng A. 2014;615:107–115. doi: 10.1016/j.msea.2014.07.054
25.
SpeerJG, De MoorE, FindleyKO, Analysis of microstructure evolution in quenching and partitioning automotive sheet steel. Metall Mater Trans A. 2011;42(12):3591–3601. doi: 10.1007/s11661-011-0869-7
26.
HanlonDN, van BohemenSMC, CelottoS.Critical assessment 10: tensile elongation of strong automotive steels as function of testpiece geometry. Mater Sci Technol. 2014;31(4):385–388. doi: 10.1179/1743284714Y.0000000707
27.
YiHL, LeeKY, BhadeshiaHKDH.Extraordinary ductility in Al-bearing – TRIP steel', proceedings of the royal society A: mathematical. Phys Eng Sci. 2011;467:234–243. doi: 10.1098/rspa.2010.0127
28.
YiHL, LeeKY, BhadeshiaHKDH.Mechanical stabilisation of retained austenite in δ-TRIP steel. Mater Sci Eng A. 2011;528(18):5900–5903. doi: 10.1016/j.msea.2011.03.111
29.
ChenP, WangGD, CeguerraAV, Yield strength enhancement by carbon trapping in ferrite. Metall Mater Trans A. 2018;49(1):235–240. doi: 10.1007/s11661-017-4364-7
30.
ZouDQ, LiSH, HeJ.Temperature and strain rate dependent deformation induced martensitic transformation and flow behavior of quenching and partitioning steels. Mater Sci Eng A. 2017;680:54–63. doi: 10.1016/j.msea.2016.10.083
