Influence of rare earth Ce on hot deformation behavior of as-cast Mn18Cr18N high nitrogen austenitic stainless steel

Abstract

The hot deformation behavior of Mn18Cr18N and Mn18Cr18N+Ce high nitrogen austenitic stainless steels at 1173–1473 K and 0.01–1 s⁻¹ were investigated by thermal compression tests. The influence mechanism of Ce on the hot deformation behavior was analyzed by Ce-containing inclusions and segregation of Ce. The results show that after the addition of Ce, large, angular, hard, and brittle inclusions (TiN-Al₂O₃, TiN, and Al₂O₃) can be modified to fine and dispersed Ce-containing inclusions (Ce-Al-O-S and TiN-Ce-Al-O-S). During the solidification, Ce-containing inclusions can be used as heterogeneous nucleation particles to refine as-cast grains. During the hot deformation, Ce-containing inclusions can pin dislocation movement and grain boundary migration, induce dynamic recrystallization (DRX) nucleation, and avoid the formation and propagation of micro cracks and gaps. In addition, during the solidification, Ce atoms enrich at the front of solid—liquid interface, resulting in composition supercooling and refining the secondary dendrites. Similarly, during the hot deformation, Ce atoms tend to segregate at the boundaries of DRX grains, inhibiting the growth of grains. Under the synergistic effect of Ce-containing inclusions and Ce segregation, although the hot deformation resistance and hot deformation activation energy are improved, DRX is more likely to occur and the size of DRX grains is significantly refined, and the problem of hot deformation cracking can be alleviated. Finally, the microhardness of the samples was measured. The results show that compared with as-cast samples, the microhardness of hot-deformed samples increases significantly, and with the increase of DRX degree, the microhardness decreases continuously. In addition, Ce can affect the microhardness of Mn18Cr18N steel by affecting as-cast and hot deformation microstructures.

Keywords

rare earth / hot deformation / Mn18Cr18N steel / non-metallic inclusions / element segregation / microhardness

References

[1] Gao CH, Ren TL, Liu M. Low-cycle fatigue characteristics of Cr₁₈Mn₁₈N_0.6 austenitic steel under strain controlled condition at 100°C. Int. J. Fatigue, 2019, 118, 35.

[2] H. Teuber, J. Barnikel, M. Dankert, W. David, A. Ghicov, and S. Voss, Development of a new high-strength steel for low pressure steam turbine end-stage blades, J. Eng. Gas Turbines Power, 141(2019), No. 1, art. No. 011021.

[3] Zhao CZ, Wei SS, Gao YL, Wang YH. Progress of heat-resistant steel for supercritical and ultra-supercritical steam turbine. J. Iron Steel Res., 2007, 19(9): 1

[4] He WW, Sun SL, Liu JS, Guo HG. Static recrystallization microstructure and model of Mn18Cr18N retaining rings steel. Mater. Sci. Technol., 2014, 22(6): 17

[5] He WW, Liu JS, Guo YF, Chen HQ, Guo HG. Microstructure evolution of multi-heats forging of Mn18Cr18N retaining ring steel and numerical simulation. J. Plast. Eng., 2010, 17(2): 45

[6] Li F, Zhang HY, He WW, Chen HQ, Guo HG. Compression and tensile consecutive deformation behavior of Mn18Cr18N austenite stainless steel. Acta Metall. Sin., 2016, 52(8): 956

[7] Qin FM, Zhu H, Wang ZX, Zhao XD, He WW, Chen HQ. Dislocation and twinning mechanisms for dynamic recrystallization of as-cast Mn18Cr18N steel. Mater. Sci. Eng. A, 2017, 684, 634.

[8] Zhu DL, Zhang M, Wang Y. Electron backscattered diffraction study of microstructural evolution during isothermal deformation of high-N Mn18Cr18 alloy. Metall. Mater. Trans. B, 2019, 50(4): 1662.

[9] Wang ZH, Sun SH, Wang B, Shi ZP, Zhang RH, Fu WT. Effect of grain size on dynamic recrystallization and hot-ductility behaviors in high-nitrogen CrMn austenitic stainless steel. Metall. Mater. Trans. A, 2014, 45(8): 3631.

[10] Gao JZ, Fu PX, Liu HW, Li DZ. Effects of rare earth on the microstructure and impact toughness of H13 steel. Metals, 2015, 5(1): 383.

[11] Yin FX, Wang L, Xiao ZX, Feng JH, Zhao L. Effect of titanium and rare earth microalloying on microsegregation, eutectic carbides of M2 high speed steel during ESR process. J. Rare Earths, 2020, 38(9): 1030.

[12] Huang Y, Liu WN, Zhao AM, Han JK, Wang ZG, Yin HX. Effect of Mo content on the thermal stability of Ti-Mo-bearing ferritic steel. Int. J. Miner. Metall. Mater., 2021, 28(3): 412.

[13] Šuler B, Burja J, Medved J. Modification of non-metallic inclusions with rare-earth metals in 50CrMoV13-1 steel. Mater. Tehnol., 2019, 53(3): 441.

[14] Hu HQ, Zhong XY, Li H. Influence of Ce on crystal morphology of austenite and dendritic segregation of Mn in high-Mn steel. Acta Metall. Sin., 1984, 20(4): 247

[15] Stanford N, Callaghan MD, Jong BD. The effect of rare earth elements on the behaviour of magnesium-based alloys: Part 1—Hot deformation behaviour. Mater. Sci. Eng. A, 2013, 565, 459.

[16] Yan HH, Hu Y, Zhao DW. Influence of rare earth on dynamic recrystallization behavior of as-cast 30Mn steel. Adv. Mater. Sci. Eng., 2018, 2018, 8423415.

[17] Łukaszek-Sołek A, Śleboda T, Krawczyk J, Bednarek S, Wojtaszek M. Characterization of the workability of Ni-Fe-Mo alloy by complex processing maps. J. Alloys Compd., 2019, 797, 174.

[18] L.W. Xu, H.B. Li, Z.H. Jiang, M.H. Cai, W.C. Jiao, H. Feng, S.C. Zhang, and P.C. Lu, Hot deformation behavior of P550 steels for nonmagnetic drilling collars, Steel Res. Int., 91(2020), No. 8, art. No. 2000035.

[19] Zang QY, Jin YF, Zhang T, Yang YT. Effect of yttrium addition on microstructure, mechanical and corrosion properties of 20Cr13 martensitic stainless steel. J. Iron Steel Res. Int., 2020, 27(4): 451.

[20] Pan XQ, Yang J, Park J, Ono H. Distribution characteristics of inclusions along with the surface sliver defect on the exposed panel of automobile: A quantitative electrolysis method. Int. J. Miner. Metall. Mater., 2020, 27(11): 1489.

[21] Gu C, Liu WQ, Lian JH, Bao YP. In-depth analysis of the fatigue mechanism induced by inclusions for high-strength bearing steels. Int. J. Miner. Metall. Mater., 2021, 28(5): 826.

[22] Lei JL, Xue ZL, Zhu HY, Jiang YD. Research progress on non-metallic inclusion in tire cord steel for radial tire. J. Iron Steel Res., 2018, 30(11): 847

[23] Costa e Silva ALVD. The effects of non-metallic inclusions on properties relevant to the performance of steel in structural and mechanical applications. J. Mater. Res. Technol., 2019, 8(2): 2408.

[24] Bramfitt BL. The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron. Metall. Trans., 1970, 1(7): 1987.

[25] Li M, Li JM, Qiu D, Zheng Q, Wang G, Zhang MX. Crystallographic study of grain refinement in low and medium carbon steels. Philos. Mag., 2016, 96(15): 1556.

[26] Yu YC, Zhang SH, Li H, Wang SB. Effects of rare earth lanthanum on the solidification structure and hot ductility of Fe-43Ni expansion alloy. High Temp. Mater. Process., 2018, 37(3): 261.

[27] El Wahabi M, Gavard L, Montheillet F, Cabrera JM, Prado JM. Effect of initial grain size on dynamic recrystallization in high purity austenitic stainless steels. Acta Mater., 2005, 53(17): 4605.

[28] N. Choi, N. Park, J.K. Kim, A.V. Karasev, P.G. Jönsson, and J.H. Park, Influence of manufacturing conditions on inclusion characteristics and mechanical properties of FeCrNiMnCo alloy, Metals, 10(2020), No. 10, art. No. 1286.

[29] Nayan N, Murty SVSN, Chhangani S, Prakash A, Prasad MJNV, Samajdar I. Effect of temperature and strain rate on hot deformation behavior and microstructure of Al-Cu-Li alloy. J. Alloys Compd., 2017, 723, 548.

[30] S.M. Lv, C.L. Jia, X.B. He, Z.P. Wan, Y. Li, and X.H. Qu, Hot deformation characteristics and dynamic recrystallization mechanisms of a novel nickel-based superalloy, Adv. Eng. Mater., 22(2020), No. 12, art. No. 2000622.

[31] Schmid-Fetzer R, Kozlov A. Thermodynamic aspects of grain growth restriction in multicomponent alloy solidification. Acta Mater., 2011, 59(15): 6133.

[32] J.B. Zhang, Y.C. Zhang, F. Zhang, D.X. Cui, Y.M. Zhao, H.X. Wu, X.Z. Wang, Q. Zhou, and H.F. Wang, Dendrite growth and grain “coarsening” in an undercooled CoNi equiatomic alloy, J. Alloys Compd., 816(2020), art. No. 152529.

[33] Yang QX, Wang A, Gao M, Wu HQ, Guo TB. Effect of rare earth elements on austenite growth dynamics of steel 9Cr2Mo. J. Iron Steel Res. Int., 1996, 3(1): 43

[34] Wang H, Bao YP, Zhao M, Wang M, Yuan XM, Gao S. Effect of Ce on the cleanliness, microstructure and mechanical properties of high strength low alloy steel Q690E in industrial production process. Int. J. Miner. Metall. Mater., 2019, 26(11): 1372.