The Q&P process of hot-rolled medium manganese steel (0.11C, 4.95Mn, 1.6Si,0.34Crwt-%) was studied and annealing at 660°C was selected to investigate the mechanism of microstructure evolution of medium manganese steel at different partitioning temperatures, and SEM, EBSD, XRD and transmission electron microscopy were used to analyse and observe the medium manganese steel. The results show that the partitioning temperature affects the distribution of martensite and austenite, with the parallel distribution of martensite being thicker and longer, making the austenite distributed between them more stable; the retained austenite at the boundary of the short rod-like martensite is subjected to larger deformation forces and is less stable. The best overall performance of the test steel was achieved when the partitioning temperature was 230°C, with a total elongation after breaking of 27.4%, and the product of tensile strength and elongation was 34.8 GPa-%.
Get full access to this article
View all access options for this article.
References
1.
HuZXuYLiuHet al.Microstructure evolution and mechanical properties of cold-rolled Mn-Al TRIP steel with δ ferrite. Chin J Mater Res. 2018;32:177–183.
2.
ShaoCHuiWZhangYet al.Microstructure and mechanical properties of hot- rolled medium-Mn steel containing 3% aluminum. MatSci Eng A Struc. 2017;682:45–53. doi:10.1016/j.msea.2016.11.036
3.
CaiZHDingHKamoutsiHet al.Interplay between deformation behavior and mechanical properties of intercritically annealed and tempered medium -manganese transformation-induced plasticity steel. Mat Sci Eng A Struc. 2016;654:359–367. doi:10.1016/j.msea.2015.12.057
4.
CaiMHuangHSuJet al.Enhanced tensile properties of a reversion annealed 6.5Mn-TRIP alloy via tailoring initial microstructure and cold rolling reduction. J Mater Sci Technol. 2017;34:1428–1435. doi:10.1016/j.jmst.2017.12.008
5.
LeeSJLeeSDe CoomanBC.Martensite transformation of sub-micron retained austenite in ultra-fine grained manganese trans-formation-induced plasticity steel. Int J Mater Res. 2013;104:423–429. doi:10.3139/146.110882
6.
JungYSLeeYKMatlockDKet al.Effect of grain size on strain-induced martensitic transformation start temperature in an ultrafine grained metastable austenitic steel. Met Mater Int. 2011;17:553–556. doi:10.1007/s12540-011-0804-x
7.
ChiangJLawrenceBBoydJDet al.Effect of microstructure on retained austenite stability and work hardening of TRIP steels. Mat Sci Eng A Struct. 2011;528:4516–4521. doi:10.1016/j.msea.2011.02.032
8.
JacquesPJDelannayFLadriereJ.On the influence of interactions between phases on the mechanical stability of retained austenite. Metall Mater Trans A. 2001;32:2759–2768.
9.
SpeerJMatlockDKDe CoomanBCet al.Quenching and partitioning: a fundamentally new process to create high strength trip sheet microstructures. Acta Mater. 2003;51:2611–2622. doi:10.1016/S1359-6454(03)00059-4
10.
SeoEJLawrenceCDe CoomanetBC.Application of quenching and partitioning processing to medium Mn steel. Metall Mater Trans A. 2015;46:27–31. doi:10.1007/s11661-014-2657-7
11.
JirkovaHKuc erovaLPru chaVet al.Effect of advanced thermo-mechanical treatment on mechanical properties of low alloyed high strength steels. Metall Mater. 2012: 532–538.
12.
De MoorESpeerJGMatlockDKet al.Effect of carbon and manga-nese on the quenching and partitioning response of CMnSi steels. ISIJ Int. 2011;51:137–144. doi:10.2355/isijinternational.51.137
13.
TanXDXuYBYangXLet al.Microstructure-properties relationship in a one- step quenched and partitioned steel. Mater Sci Eng A. 2014;589:101–111. doi:10.1016/j.msea.2013.09.063
14.
LeeSDe CoomanBC.Tensile behavior of intercritically annealed 10 pct Mn multi-phase steel. Metall Mater Trans. 2014;45(2):709–716.
15.
YangFLuoHHuCet al.Effects of intercritical annealing process on microstructures and tensile properties of cold-rolled 7Mn steel. Mater Sci Eng A. 2017;685(FEB.8):115–122.
16.
LeeSDe CoomanBC.Tensile behavior of intercritically annealed 10 pct Mn multi-phase steel. Metall Mater Trans. 2014;45(2):709–716.
17.
WangCYShiJCaoWQet al.Characterization of microstructure obtained by quenching and partitioning process in low alloy martensitic steel. Mater Sci Eng A. 2010;527(15):3442–3449. doi:10.1016/j.msea.2010.02.020
18.
PengFXuYGuXet al.The relationships of microstructure- mechanical properties in quenching and partitioning (Q&P) steel accompanied with microalloyed carbide precipitation. Mater Sci Eng A. 2018;723:247–258. doi:10.1016/j.msea.2018.03.061
19.
HidalgoJFindleyKOSantofimiaMJ.Thermal and mechanical stability of retained austenite surrounded by martensite with different degrees of tempering. Mater Sci Eng A. 2017;690(6):337–347. doi:10.1016/j.msea.2017.03.017
20.
SongCYuHLiLet al.The stability of retained austenite at different locations during straining of I&Q& amp;P steel. Mater Sci Eng A. 2016;670:326–334.
21.
ToshihiroTJunyaTTeruyukiTet al.Quenching and partitioning treatment of a low-carbon martensitic stainless steel. Mater Sci Eng A. 2012;532:85–592.
22.
LiZCMisraRDKCaiZHet al.Mechanical 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 Struc. 2016;673:63–72. doi:10.1016/j.msea.2016.07.023
23.
TaoLYanFLeiLet al.Influence of partitioning temperature on microstructure and mechanical performance of medium manganese Fe-C-Mn-Cu-Cr-Mo-Nb steel. Metals (Basel). 2022;12(12):2147.
