In order to find an alternative choice for structural load-bearing components, an effort was made to improve the impact toughness of medium Mn steel through inter-critical annealing treatment without significant reduction in strength. Besides, the relative effect of C and Mn contents on microstructure and mechanical properties of medium Mn steels was also studied. Fibrous microstructures with fine, alternate films of ferrite and martensite with retained austenite were obtained. The low-C, high-Mn steel showed a superior combination of yield strength, ductility and impact toughness due to finer microstructure and higher retained austenite fraction, as compared to high-C, low-Mn steel. Thus, the beneficial effect of Mn enrichment in stabilising retained austenite and improving mechanical properties by transformation induced plasticity effect becomes evident.
JangJM, KimSJ, KangNH, Effects of annealing conditions on microstructure and mechanical properties of low carbon, manganese transformation-induced plasticity steel. Met Mater Int. 2009;15:909–916. doi: 10.1007/s12540-009-0909-7
2.
De MoorE, MatlockDK, SpeerJG, Austenite stabilization through manganese enrichment. Scr Mater. 2011;64:185–188. doi: 10.1016/j.scriptamat.2010.09.040
3.
CaiZH, DingH, MisraRDK, Austenite stability and deformation behavior in a cold-rolled transformation-induced plasticity steel with medium manganese content. Acta Mater. 2015;84:229–236. doi: 10.1016/j.actamat.2014.10.052
4.
JacquesP, FurnémontQ, PardoenT, On the role of martensitic transformation on damage and cracking resistance in TRIP-assisted multiphase steels. Acta Mater. 2001;49:139–152. doi: 10.1016/S1359-6454(00)00215-9
5.
XiongXC, ChenB, HuangMX, The effect of morphology on the stability of retained austenite in a quenched and partitioned steel. Scr Mater. 2013;68:321–324. doi: 10.1016/j.scriptamat.2012.11.003
6.
MillerRL.Ultrafine-grained microstructures and mechanical properties of alloy steels. Metall Trans. 1972;3:905–912. doi: 10.1007/BF02647665
7.
GibbsPJ, De MoorE, MerwinMJ, Austenite stability effects on tensile behavior of manganese-enriched- austenite transformation-induced plasticity steel. Metall Mater Trans A. 2011;42:691–3702. doi: 10.1007/s11661-011-0687-y
8.
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
9.
ShiJ, SunX, WangM, Enhanced work-hardening behavior and mechanical properties in ultrafine-grained steels with large-fractioned metastable austenite. Scr Mater. 2010;63:815–818. doi: 10.1016/j.scriptamat.2010.06.023
10.
ZouY, XuYB, HuZP, Austenite stability and its effect on the toughness of a high strength ultra-low carbon medium manganese steel plate. Mater Sci Eng A. 2016;675:153–163. doi: 10.1016/j.msea.2016.07.104
11.
HanJ, LeeYK.The effects of the heating rate on the reverse transformation mechanism and the phase stability of reverted austenite in medium Mn steels. Acta Mater. 2014;67:354–361. doi: 10.1016/j.actamat.2013.12.038
12.
LiuH, LuX, JinX, Enhanced mechanical properties of a hot stamped advanced high-strength steel treated by quenching and partitioning process. Scr Mater. 2011;64:749–752. doi: 10.1016/j.scriptamat.2010.12.037
13.
HanHN, OhCS, KimG, Design method for TRIP-aided multiphase steel based on a microstructure-based modelling for transformation-induced plasticity and mechanically induced martensitic transformation. Mater Sci Eng A. 2009;499:462–468. doi: 10.1016/j.msea.2008.09.026
14.
LeeS, LeeSJ, 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
15.
SpeerJG, De MoorE, FindleyKO, Analysis of microstructure evolution in quenching and partitioning automotive sheet steel. Metall Mater Trans A. 2011;42:3591–3601. doi: 10.1007/s11661-011-0869-7
16.
LeeS, De CoomanBC.On the selection of the optimal intercritical annealing temperature for medium Mn TRIP steel. Metall Mater Trans A. 2013;44:5018–5024. doi: 10.1007/s11661-013-1860-2
17.
LiZC, DingH, MisraRDK, Microstructure-mechanical property relationship and austenite stability in medium-Mn TRIP steels: The effect of austenite-reverted transformation and quenching-tempering treatments. Mater Sci Eng A. 2017;682:211–219. doi: 10.1016/j.msea.2016.11.048
18.
AndersonTL.Fracture mechanics: fundamentals and applications. London: CRC Press; 1995.
19.
DuchateauD, GuttmannM.An X-ray microanalysis study of the partition of manganese in 6 and 9% Mn cryogenic steels and its influence on the stability of austenite dispersed in a tempered martensitic matrix. Acta Metall. 1981;29:1291–1297. doi: 10.1016/0001-6160(81)90020-1
20.
KimJI, MorrisJW.The composition of precipitated austenite in 5.5Ni steel. Metall Trans A. 1981;12:1957–1963. doi: 10.1007/BF02643809
21.
FurukawaT, HuangH, MatsumuraO.Effects of carbon content on mechanical properties of 5% Mn steels exhibiting transformation induced plasticity. Mater Sci Technol. 1994;10:964–970. doi: 10.1179/mst.1994.10.11.964
22.
BhattacharyyaT, SinghSB, DasS, Development and characterisation of C-Mn-Al-Si-Nb TRIP aided steel. Mater Sci Eng A. 2011;528:2394–2400. doi: 10.1016/j.msea.2010.11.054
23.
LancasterJF.Metallurgy of welding. London: Woodhead Publishing Limited; 1980.
24.
SkMB, GhoshA, RarhiN, Effect of reheating temperature and cooling treatment on the microstructure, texture, and impact transition behavior of heat-treated naval grade HSLA steel. Metall Mater Trans A. 2017;48:3231–3247. doi: 10.1007/s11661-017-4099-5
25.
SugimotoK, YuB, MukaiY, Microstructure and formability of aluminum bearing TRIP-aided steels with annealed martensite matrix. ISIJ Int. 2005;45:1194–1200. doi: 10.2355/isijinternational.45.1194
26.
American Society for Testing and Materials (ASTM). Standard test methods for tension testing of metallic materials-vol03.01. Pennsylvania: ASTM; 2005. Standard No.ASTME8/E8M-09.
27.
American Society for Testing and Materials (ASTM). Standard test methods for notched bar impact testing of metallic materials-vol 03.01. Pennsylvania: ASTM; 2005. Standard No.ASTME23-05.
28.
QiuH, OhmoriA, HagiwaraY.Mechanical properties of welded joints of 780 MPa grade ultra-fine grained steels. ISIJ Int. 2003;43:2046–2053. doi: 10.2355/isijinternational.43.2046
29.
European structural steel standard. Part 6: Technical delivery conditions for flat products of high yield strength structural steels in the quenched and tempered condition. UK; 2004. Standard No. EN 10025:2004.
30.
LeeS, De CoomanBC.Influence of carbide precipitation and dissolution on the microstructure of ultra-fine-grained intercritically annealed medium manganese steel. Metall Mater Trans A. 2016;47:3263–3270. doi: 10.1007/s11661-016-3507-6
31.
SpeichGR, DemarestVA, MillerRL.Formation of austenite during intercritical annealing of dual-phase steels. Metall Mater Trans A. 1981;12:1419–1428. doi: 10.1007/BF02643686
32.
MonteiroSN, Reed-HillRE.On the Double-n Behavior of Iron. 1971;2:0–1.
33.
CaiXL, Garratt-ReedAJ, OwenWS.The development of some dual-phase steel structures from different starting microstructures. Metall Trans A. 1985;16:543–557. doi: 10.1007/BF02814228
34.
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
35.
SugimotoK, KobayashiM, HashimotoS, Ductility and strain-induced transformation in a high-strength TRIP aided dual phase steel. Metall Trans A. 1992;23:3085–3091. doi: 10.1007/BF02646127
36.
KarmakarA, SivaprasadS, KunduS, Tensile behavior of ferrite-carbide and ferrite-martensite steels with different ferrite grain structures. Metall Mater Trans A. 2014;45:1659–1664. doi: 10.1007/s11661-014-2228-y
37.
DasD, ChattopadhyayPP.Influence of martensite morphology on the work-hardening behavior of high strength ferrite-martensite dual-phase steel. J Mater Sci. 2009;44:2957–2965. doi: 10.1007/s10853-009-3392-0
38.
JiangZH, GuanZZ, LianJS.Effects of microstructural variables on the deformation-behavior of dual-phase steel. Mater Sci Eng. 1995;190:55–64. doi: 10.1016/0921-5093(94)09594-M
39.
JhaBK, AvtarR, DwivediVS.Applicability of modified Crussard-Jaoul analysis on the deformation behaviour of dual-phase steels. J Mater Sci Lett. 1987;6:891–893. doi: 10.1007/BF01729860
