A new type of cold-rolled medium manganese steel was investigated. The test steel was treated by Q&P process. With the increase in annealing temperature, the grain size gradually increases, the carbides dissolve progressively and the fine lath grains transform into massive or equiaxed grains. Both the volume fraction and the stability of the retained austenite are continuously decreasing, which together affect the change of mechanical properties. At the intercritical annealing temperature of 680°C, the specimens have higher retained austenite content and transformation rate. At the same time, due to the discontinuous TRIP effect caused by the retained austenite stability gradient inside the specimen, it exhibits excellent comprehensive mechanical properties, and the product of strength and elongation is 43.5GPa·%.
CaiZHDingHMisraRDKAustenite stability and deformation behavior in a cold-rolled transformation-induced plasticity steel with medium manganese content. Acta Mater. 2015;84:229–236.
2.
MatlockDKSpeerJG. Third generation of AHSS: microstructure design concepts. 2009; p. 185–205.
3.
HuBLuoH.A strong and ductile 7Mn steel manufactured by warm rolling and exhibiting both transformation and twinning induced plasticity. J Alloy Compd. 2017;725:684–693.
4.
CoomanBCD.High Mn TWIP steel and medium Mn steel. South Korea: Automotive Steels; 2017.
5.
SohnSSSongHJJoMC.Novel 1.5 GPa-strength with 50%-ductility by transformation-induced plasticity of non-recrystallized austenite in duplex steels. Science. 2017;7:1255.
6.
SomaniMCJuntunenetPKarjalainenalLP.Enhanced mechanical properties through reversion in metastable austenitic stainless steels. Metall Mater Trans A. 2009;40:729–744.
7.
SohnSSLeeBJLeeSEffect of annealing temperature on microstructural modification and tensile properties in 0.35 C–3.5 Mn–5.8 Al lightweight steel. Acta Mater. 2013;61(13):5050–5066.
8.
XuWRivera-Díaz-Del-CastilloEJPYanWA new ultrahigh-strength stainless steel strengthened by various coexisting nanoprecipitates. Acta Mater. 2010;58(11):4067–4075.
9.
SpeerJMatlockDKCooman DeBCCarbon partitioning into austenite after martensite transformation. Acta Mater. 2003;51:2611–2622.
10.
AjcaBJgsAMkmCCarbon partitioning to austenite from martensite or bainite during the quench and partition (Q&P) process: a critical assessment. Acta Mater. 2008;56:16–22.
11.
SpeerJGMoorEDFindleyKOAnalysis of microstructure evolution in quenching and partitioning automotive sheet steel. Metall Mater Trans A. 2011;42(12):3591–3601.
12.
LiJSongRLiXMicrostructural evolution and tensile properties of 70GPa·% grade strong and ductile hot-rolled 6Mn steel treated by intercritical annealing. Mat Sci Eng A. 2019;745:212–220.
13.
LeeSDe CoomanBC.Tensile behavior of intercritically annealed 10 pct Mn multi-phase steel. Metall Mater Trans A. 2014;45(2):709–716.
14.
ZhangZRSongRBZhouNPMicrostructure evolution and mechanical properties of 67GPa% grade medium manganese steel. Mater Sci Forum. 2021;1035:404–409.
15.
ZouYHanYLiuHSMicrostructure evolution and enhanced mechanical properties of a novel Nb-Ti micro-alloyed medium-Mn steel. Mater Charact. 2022;187:111828.
16.
ModassirAAkhilKSahuJKPhase transformations and numerical modelling in simulated HAZ of nanostructured P91B steel for high temperature applications. Appl Nanosci. 2018;8:1669–1685.
17.
ModassirAAkhilK.The synergistic effects among crystal orientations, creep parameters, local strain, macro–microdeformation, and polycrystals’ hardness of boron alloyed P91 steels. Steel Res Int. 2022;93:2100819.
18.
LuJHaoYKangPStudy of microstructure, mechanical properties and impact-abrasive wear behavior of medium-carbon steel treated by quenching and partitioning (Q&P) process. Wear. 2018;414–415:21–30.
19.
ZhuangDWTangYJQinZZ.Materials analysis methods. Beijing: China Machine Press; 2013.
20.
Khajuria1AAkhtarMBediR.Boron addition to AISI A213/P91 steel: preliminary investigation on microstructural evolution and microhardness at simulated heat-affected zone. Materialwiss Werkst. 2022;53:1167–1183.
21.
SohnSSSongHKwakJHDramatic improvement of strain hardening and ductility to 95% in highly-deformable high-strength duplex lightweight steels. Sci Rep-UK. 2017;7(1):1927.
22.
ChiangJLawrenceBBoydJDEffect of microstructure on retained austenite stability and work hardening of TRIP steels. Mat Sci Eng A. 2011;528(13):4516–4521.
23.
SuhDWRyuJHJooMSMedium-alloy manganese-rich transformation induced plasticity steels. Metall Mater Trans A. 2013;44:286–293.
24.
ShiJSunXWangMEnhanced work-hardening behavior and mechanical properties in ultrafine-grained steels with large-fractioned metastable austenite. Scripta Mater. 2010;63(8):815–818.
25.
LiZCMisraRCaiZHMechanical properties and deformation behavior in hot-rolled 0.2C-1.5/3Al-8.5Mn-Fe TRIP steel: the discontinuous TRIP effect. Mat Sci Eng A. 2016;673:63–72.
26.
LiZCDingHCaiZH.Mechanical properties and austenite stability in hot-rolled 0.2C–1.6/3.2Al–6Mn–Fe TRIP steel. Mat Sci Eng A. 2015;639:559–566.
27.
HuBHeBBChengGJSuper-high-strength and formable medium Mn steel manufactured by warm rolling process. Acta Mater. 2019;174:131–141.
28.
CaiZHDingHXueXSignificance of control of austenite stability and three-stage work-hardening behavior of an ultrahigh strength–high ductility combination transformation-induced plasticity steel. Scripta Mater. 2013;68(11):865–868.
29.
LeeSJLeeSCoomanBCD.Martensite transformation of sub-micron retained austenite in ultra-fine grained manganese transformation-induced plasticity steel. Int J Mater Res. 2013;104(5):423–429.
30.
JungYSLeeYKMatlockDKEffect of grain size on strain-induced martensitic transformation start temperature in an ultrafine grained metastable austenitic steel. Met Mater Int. 2011;17(4):553–556.
31.
ChiangJLawrenceBBoydJDEffect of microstructure on retained austenite stability and work hardening of TRIP steels. Mat Sci Eng A. 2011;528(13):4516–4521.
