Hot ductility behavior of a Fe-0.3C-9Mn-2Al medium Mn steel

Abstract

The hot ductility of a Fe-0.3C-9Mn-2Al medium Mn steel was investigated using a Gleeble3800 thermo-mechanical simulator. Hot tensile tests were conducted at different temperatures (600–1300°C) under a constant strain rate of 4 × 10⁻³ s⁻¹. The fracture behavior and mechanism of hot ductility evolution were discussed. Results showed that the hot ductility decreased as the temperature was decreased from 1000°C. The reduction of area (RA) decreased rapidly in the specimens tested below 700°C, whereas that in the specimen tested at 650°C was lower than 65%. Mixed brittle-ductile fracture feature is reflected by the coexistence of cleavage step, intergranular facet, and dimple at the surface. The fracture belonged to ductile failure in the specimens tested between 720–1000°C. Large and deep dimples could delay crack propagation. The change in average width of the dimples was in positive proportion with the change in RA. The wide austenite-ferrite inter-critical temperature range was crucial for the hot ductility of medium Mn steel. The formation of ferrite film on austenite grain boundaries led to strain concentration. Yield point elongation occurred at the austenite-ferrite intercritical temperature range during the hot tensile test.

Keywords

medium Mn steel / hot ductility / reduction of area / fracture behavior / microstructure characterization

References

[1] He BB, Hu B, Yen HW, Cheng GJ, Wang ZK, Luo HW, Huang MX. High dislocation density-induced large ductility in deformed and partitioned steels. Science, 2017, 357(6355): 1029.

[2] Xia PK, Vercruysse F, Petrov R, Sabirov I, Castillo-Rodríguez M, Verleysen P. High strain rate tensile behavior of a quenching and partitioning (Q&P) Fe-0.25C-1.5Si-3.0Mn steel. Mater. Sci. Eng. A, 2019, 745, 53.

[3] Grajcar A, Kuziak R, Zalecki W. Third generation of AHSS with increased fraction of retained austenite for the automotive industry. Arch. Civ. Mech. Eng., 2012, 12(3): 334.

[4] Lu K. The future of metals. Science, 2010, 328(5976): 319.

[5] Zhao JW, Jiang ZY. Thermomechanical processing of advanced high strength steels. Prog. Mater Sci., 2018, 94, 174.

[6] Lan P, Tang HY, Zhang JQ. Hot ductility of high alloy Fe-Mn-C austenite TWIP steel. Mater. Sci. Eng. A, 2016, 660, 127.

[7] Chen BH, Yu H. Hot ductility behavior of V-N and V-Nb microalloyed steels. Int. J. Miner. Metall. Mater., 2012, 19(6): 525.

[8] Lee CH, Park JY, Chung JH, Park DB, Jang JY, Huh S, Kim SJ, Kang JY, Moon J, Lee TH. Hot ductility of medium carbon steel with vanadium. Mater. Sci. Eng. A, 2016, 651, 192.

[9] Mejía I, Bedolla-Jacuinde A, Maldonado C, Cabrera JM. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron. Mater. Sci. Eng. A, 2011, 528(13–14): 4468.

[10] Hu B, Luo HW, Yang F, Dong H. Recent progress in medium-Mn steels made with new designing strategies, a review. J. Mater. Sci. Technol., 2017, 33(12): 1457.

[11] Benzing JT, Kwiatkowski Da Silva A, Morsdorf L, Bentley J, Ponge D, Dutta A, Han J, McBride JR, Van Leer B, Gault B, Raabe D, Wittig JE. Multi-scale characterization of austenite reversion and martensite recovery in a cold-rolled medium-Mn steel. Acta Mater., 2019, 166, 512.

[12] Suh DW, Kim SJ. Medium Mn transformation-induced plasticity steels: Recent progress and challenges. Srripta Mater., 2017, 126, 63.

[13] Steineder K, Krizan D, Schneider R, Béal C, Sommitsch C. On the microstructural characteristics influencing the yielding behavior of ultra-fine grained medium-Mn steels. Acta Mater., 2017, 139, 39.

[14] Hu J, Zhang JM, Sun GS, Du LX, Liu Y, Dong Y, Misra RDK. High strength and ductility combination in nano-/ultrafine-grained medium-Mn steel by tuning the stability of reverted austenite involving intercritical annealing. J. Mater. Sci., 2019, 54(8): 6565.

[15] Kang MH, Lee JS, Koo YM, Kim SJ, Heo NH. Correlation between MnS precipitation, sulfur segregation kinetics, and hot ductility in C-Mn steel. Metall. Mater. Trans. A, 2014, 45(12): 5295.

[16] Ma Y, Song WW, Zhou SX, Schwedt A, Bleck W. Influence of intercritical annealing temperature on microstructure and mechanical properties of a cold-rolled medium-Mn steel. Metals, 2018, 8(5): 357.

[17] Nakada N, Mizutani K, Tsuchiyama T, Takaki S. Difference in transformation behaviour between ferrite and austenite formations in medium manganese steel. Acta Mater., 2014, 65, 251.

[18] Li JY, Cheng GG. Hot ductility of Cr15Mn7Ni4N austenitic stainless steel. J. Mater. Res. Technol., 2020, 9(1): 52.

[19] Thomas B G, Brimacombe JK, Samarasekera I V. The formation of panel cracks in steel ingots: A state-of-the-art review-I. hot ductility of steel. ISS Trans., 1986, 7, 7.

[20] Seo SC, Son KS, Lee SK, Kim I, Lee TJ, Yim C, Kim D. Variation of hot ductility behavior in as-cast and remelted steel slab. Met. Mater. Int., 2008, 14(5): 559.

[21] Liu HB, Liu JH, Wu BW, Shen YZ, He Y, Ding H, Su XF. Effect of Mn and Al contents on hot ductility of high alloy Fe-xMn-C-yAl austenite TWIP steels. Mater. Sci. Eng. A, 2017, 708, 360.

[22] Sahoo G, Singh B, Saxena A. Effect of strain rate, soaking time and alloying elements on hot ductility and hot shortness of low alloy steels. Mater. Sci. Eng. A, 2018, 718, 292.

[23] Lu Z, Zhang HT, Wu BR. Effect of niobium on hot ductility of low C-Mn-steel under continuous casting simulation conditions. Steel Res. Int., 1990, 61(12): 620.

[24] Yang DP, Wu D, Yi HL. Reverse transformation from martensite into austenite in a medium-Mn steel. Scripta Mater., 2019, 161, 1.

[25] Hamada AS, Karjalainen LP. Hot ductility behaviour of high-Mn TWIP steels. Mater. Sci. Eng. A, 2011, 528(3): 1819.

[26] Li JR, He T, Cheng LJ, Zhang PF, Wang LW. Effect of precipitates on the hot embrittlement of 11Cr-3Co-3W martensitic heat resistant steel for turbine high temperature stage blades in ultra-supercritical power plants. Mater. Sci. Eng. A, 2019, 763, 138187.

[27] Tu T, Chen XH, Chen J, Zhao CY, Pan FS. A high-ductility Mg-Zn-Ca magnesium alloy. Acta Metall. Sinica Engl. Lett., 2019, 32(1): 23.

[28] Wen PY, Han JS, Luo HW, Mao XP. Effect of flash processing on recrystallization behavior and mechanical performance of cold-rolled IF steel. Int. J. Miner. Metall. Mater., 2020, 27(9): 1234.

[29] Luo HW, Dong H, Huang MX. Effect of intercritical annealing on the Lüders strains of medium Mn transformation-induced plasticity steels. Mater. Des., 2015, 83, 42.

[30] De Cooman BC, Lee SJ, Shin S, Seo EJ, Speer JG. Combined intercritical annealing and Q&P processing of medium Mn steel. Metall. Mater. Trans. A, 2017, 48(1): 39.

[31] Schwab R, Ruff V. On the nature of the yield point phenomenon. Acta. Mater., 2013, 61(5): 1798.

[32] Han JH, Lee SJ, Jung JG, Lee YK. 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.