Effect of lamellarization on the microstructure and mechanical properties of marine 10Ni5CrMoV steel

Abstract

Multistage heat treatment involving quenching (Q), lamellarizing (L), and tempering (T) is applied to marine 10Ni5CrMoV steel. The microstructure and mechanical properties were studied by multiscale characterizations, and the kinetics of reverse austenite transformation, strain hardening behavior, and toughening mechanism were further investigated. The lamellarized specimens possess low yield strength but high toughness, especially cryogenic toughness. Lamellarization leads to the development of film-like reversed austenite at the martensite block and lath boundaries, refining the martensite structure and lowering the equivalent grain size. Kinetic analysis of austenite reversion based on the JMAK model shows that the isothermal transformation is dominated by the growth of reversed austenite, and the maximum transformation of reversed austenite is reached at the peak temperature (750°C). The strain hardening behavior based on the modified Crussard–Jaoul analysis indicates that the reversed austenite obtained from lamellarization reduces the proportion of martensite, significantly hindering crack propagation via martensitic transformation during the deformation. As a consequence, the QLT specimens exhibit high machinability and low yield strength. Compared with the QT specimen, the ductile–brittle transition temperature of the QLT specimens decreases from −116 to −130°C due to the low equivalent grain size and reversed austenite, which increases the cleavage force required for crack propagation and absorbs the energy of external load, respectively. This work provides an idea to improve the cryogenic toughness of marine 10Ni5CrMoV steel and lays a theoretical foundation for its industrial application and comprehensive performance improvement.

Keywords

10Ni5CrMoV steel / lamellarizing / reversed austenite / cryogenic toughness / ductile–brittle transition temperature

References

[1] Dai YL, Yu SF, Huang AG, Shi YS. Microstructure and mechanical properties of high-strength low alloy steel by wire and arc additive manufacturing. Int. J. Miner. Metall. Mater.. 2020, 27(7): 933

[2] J. Wang, Y.F. Shen, W.Y. Xue, N. Jia, and R.D.K. Misra, The significant impact of introducing nanosize precipitates and decreased effective grain size on retention of high toughness of simulated heat affected zone (HAZ), Mater. Sci. Eng. A, 803(2021), art. No. 140484.

[3] S. Monschein, M. Kapp, D. Zügner, J. Fasching, A. Landefeld, and R. Schnitzer, Influence of microalloying elements and deformation parameters on the recrystallization and precipitation behavior of two low-alloyed steels, Steel Res. Int., 92(2021), No. 9, art. No. 2100065.

[4] Y. Tian, J.H. Zhou, Y.F. Shen, Z.Z. Qu, W.Y. Xue, and Z.D. Wang, Improved toughness of a high-strength low-alloy steel for Arctic ship by Ni and Mo addition, Adv. Eng. Mater., 22(2020), No. 6, art. No. 1901553.

[5] Yu C, Yang TC, Huang CY, Shiue RK. Low-temperature toughness of the austempered offshore steel. Metall. Mater. Trans. A. 2016, 47(10): 4777

[6] Fan ED, Li Y, You Y, Lü XW. Effect of crystallographic orientation on crack growth behaviour of HSLA steel. Int. J. Miner. Metall. Mater.. 2022, 29(8): 1532

[7] L. Jiang, J. Wang, T. Zhang, T. Dorin, and X.J. Sun, Superior low temperature toughness in a newly designed low Mn and low Ni high strength steel, Mater. Sci. Eng. A, 825(2021), art. No. 141899.

[8] H.W. Lee, T.M. Park, N. Seo, S.J. Lee, C.M. Lee, and J. Han, Design of low-Ni martensitic steels with novel cryogenic impact toughness exceeding 190 J, Mater. Sci. Eng. A, 840(2022), art. No. 142959.

[9] L.Y. Kan, T. Zhu, Q.B. Ye, et al., Enhanced mechanical properties of a low-carbon martensitic steel by thermally stable Ni-rich austenite, Steel Res. Int., 93(2022), No. 6, art. No. 2100562.

[10] Xu LX, Wu HB, Mou D. Effect of quenching in dual-phase region on microstructure and mechanical properties of 7Ni steel. J. Mater. Eng.. 2018, 46(8): 113

[11] Wu SJ, Sun GJ, Ma QS, Shen QY, Xu L. Influence of QLT treatment on microstructure and mechanical properties of a high nickel steel. J. Mater. Process. Technol.. 2013, 213(1): 120

[12] Khomskaya IV. Structure formed in two-phase (α + γ) field and mechanical properties of a cryogenic alloy 10N7. Phys. Met. Metallogr.. 2010, 110(2): 188

[13] Cao HW, Luo XH, Zhan GF, Liu S. Effect of Mn content on microstructure and cryogenic mechanical properties of a 7% Ni steel. Acta Metall. Sin. Engl. Lett.. 2018, 31(7): 699

[14] Cao HW, Luo XH, Zhan GF, Liu S. Influence of Nb content on microstructure and mechanical properties of a 7%Ni steel. Acta Metall. Sin. Engl. Lett.. 2018, 31(9): 975

[15] Wang SZ, Gao ZJ, Wu GL, Mao XP. Titanium microalloying of steel: A review of its effects on processing, microstructure and mechanical properties. Int. J. Miner. Metall. Mater.. 2022, 29(4): 645

[16] Li Z, Wu D. Effects of hot deformation and subsequent austempering on the mechanical properties of Si–Mn TRIP steels. ISIJ Int.. 2006, 46(1): 121

[17] Takebayashi S, Kunieda T, Yoshinaga N, Ushioda K, Ogata S. Comparison of the dislocation density in martensitic steels evaluated by some X-ray diffraction methods. ISIJ Int.. 2010, 50(6): 875

[18] Aufrecht J, Leineweber A, Foct J, Mittemeijer EJ. The structure of nitrogen-supersaturated ferrite produced by ball milling. Philos. Mag.. 2008, 88(12): 1835

[19] Christien F, Telling MTF, Knight KS. Neutron diffraction in situ monitoring of the dislocation density during martensitic transformation in a stainless steel. Scripta Mater.. 2013, 68(7): 506

[20] Wang W, Mao XD, Liu SJ, Xu G, Wang B. Microstructure evolution and toughness degeneration of 9Cr martensitic steel after aging at 550°C for 20000 h. J. Mater. Sci.. 2018, 53(6): 4574

[21] Wan QM, Wang RS, Shu GG, et al. . Analysis method of Charpy V-notch impact data before and after electron beam welding reconstitution. Nucl. Eng. Des.. 2011, 241(2): 459

[22] Wang M, Liu ZY, Li CG. Correlations of Ni contents, formation of reversed austenite and toughness for Ni-containing cryogenic steels. Acta Metall. Sin. Engl. Lett.. 2017, 30(3): 238

[23] Su GQ, Gao XH, Yan T, et al. . Intercritical tempering enables nanoscale austenite/e-martensite formation in low-C medium-Mn steel: A pathway to control mechanical properties. Mater. Sci. Eng. A. 2018, 736: 417

[24] Xie ZJ, Han G, Zhou WH, Zeng CY, Shang CJ. Study of retained austenite and nano-scale precipitation and their effects on properties of a low alloyed multi-phase steel by the two-step intercritical treatment. Mater. Charact.. 2016, 113: 60

[25] Chen QY, Ren JK, Xie ZL, Zhang WN, Chen J, Liu ZY. Correlation between reversed austenite and mechanical properties in a low Ni steel treated by ultra-fast cooling, intercritical quenching and tempering. J. Mater. Sci.. 2020, 55(4): 1840

[26] M. Pozuelo, J.W. Stremfel, J.M. Yang, and J. Marian, Strengthening to softening transition in lath martensite, Materialia, 5(2019), art. No. 100254.

[27] Morito S, Tanaka H, Konishi R, Furuhara T, Maki T. The morphology and crystallography of lath martensite in Fe–C alloys. Acta Mater.. 2003, 51(6): 1789

[28] Wang EM, Ding C, Gong N, et al. . Effect of Nb precipitates and reversed austenite formed by QLT process on microstructure and mechanical properties of Nb-bearing 7Ni cryogenic steel. Metall. Mater. Trans. A. 2024, 55(1): 247

[29] Kitahara H, Ueji R, Tsuji N, Minamino Y. Crystallographic features of lath martensite in low-carbon steel. Acta Mater.. 2006, 54(5): 1279

[30] Chiang J, Boyd JD, Pilkey AK. Effect of microstructure on retained austenite stability and tensile behaviour in an aluminum-alloyed TRIP steel. Mater. Sci. Eng. A. 2015, 638: 132

[31] Lee YK, Shin HC, Jang YC, Kim SH, Choi CS. Effect of isothermal transformation temperature on amount of retained austenite and its thermal stability in a bainitic Fe–3%Si–0.45%C–X steel. Scripta Mater.. 2002, 47(12): 805

[32] Kuzmina M, Ponge D, Raabe D. Grain boundary segregation engineering and austenite reversion turn embrittlement into toughness: Example of a 9wt.% medium Mn steel. Acta Mater.. 2015, 86: 182

[33] Morito S, Oh-ishi K, Hono K, Ohba T. Carbon enrichment in retained austenite films in low carbon lath martensite steel. ISIJ Int.. 2011, 51(7): 1200

[34] Zhang SH, Wang P, Li DZ, Li YY. Investigation of the evolution of retained austenite in Fe–13%Cr–4%Ni martensitic stainless steel during intercritical tempering. Mater. Des.. 2015, 84: 385

[35] Zhang SH, Lv DZ, Xiong J. The effect of reversed austenite on mechanical properties of 13Cr4NiMo steel: A CPFEM study. J. Mater. Res. Technol.. 2022, 18: 2963

[36] D.G. Liu, H. Ding, D. Han, and M.H. Cai, Effect of grain interior and grain boundary κ-carbides on the strain hardening behavior of medium-Mn lightweight steels, Mater. Sci. Eng. A, 871(2023), art. No. 144861.

[37] Liu GD, Luo XM, Zou JP, Zhang B, Zhang GP. Effects of grain size and cryogenic temperature on the strain hardening behavior of VCoNi medium-entropy alloys. Acta Metall. Sin. Engl. Lett.. 2023, 36(6): 973

[38] Calcagnotto M, Ponge D, Demir E, Raabe D. Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD. Mater. Sci. Eng. A. 2010, 527(10–11): 2738

[39] Ghassemi-Armaki H, Maaß R, Bhat SP, Sriram S, Greer JR, Kumar KS. Deformation response of ferrite and martensite in a dual-phase steel. Acta Mater.. 2014, 62: 197

[40] Alvarenga HD, Putte TVD, Steenberge NV, Sietsma J, Terryn H. Influence of carbide morphology and microstructure on the kinetics of superficial decarburization of C–Mn steels. Metall. Mater. Trans. A. 2015, 46(1): 123

[41] G.X. Qiu, Q. Du, X.M. Li, X.D. Xing, and D.P. Zhan, Strengthening effect of multiscale second phases in reduced activation ferrite/martensitic steel, Steel Res. Int., 93(2022), No. 4, art. No. 2100430.

[42] Oh CS, Han HN, Lee CG, Lee TH, Kim SJ. Dilatometric analysis on phase transformations of intercritical annealing of Fe–Mn–Si and Fe–Mn–Si–Cu low carbon TRIP steels. Met. Mater. Int.. 2004, 10(5): 399

[43] Huang J, Poole WJ, Militzer M. Austenite formation during intercritical annealing. Metall. Mater. Trans. A. 2004, 35(11): 3363

[44] Blázquez JS, Conde CF, Conde A. On the use of classical JMAK crystallization kinetic theory to describe simultaneous processes leading to the formation of different phases in metals. Int. J. Therm. Sci.. 2015, 88: 1

[45] Balbi M, Alvarez-Armas I, Armas A. Effect of holding time at an intercritical temperature on the microstructure and tensile properties of a ferrite–martensite dual phase steel. Mater. Sci. Eng. A. 2018, 733: 1

[46] Asadabad MA, Goodarzi M, Kheirandish S. Kinetics of austenite formation in dual phase steels. ISIJ Int.. 2008, 48(9): 1251

[47] Colla V, Sanctis MD, Dimatteo A, Lovicu G, Solina A, Valentini R. Strain hardening behavior of dual-phase steels. Metall. Mater. Trans. A. 2009, 40(11): 2557

[48] Zhao ZZ, Tong TT, Liang JH, Yin HX, Zhao AM, Tang D. Microstructure, mechanical properties and fracture behavior of ultra-high strength dual-phase steel. Mater. Sci. Eng. A. 2014, 618: 182

[49] Kamikawa N, Sato K, Miyamoto G, et al. . Stress–strain behavior of ferrite and bainite with nano-precipitation in low carbon steels. Acta Mater.. 2015, 83: 383

[50] Etesami SA, Enayati MH, Kalashami AG. Austenite formation and mechanical properties of a cold rolled ferrite–martensite structure during intercritical annealing. Mater. Sci. Eng. A. 2017, 682: 296

[51] Jiang ZH, Guan ZZ, Lian JS. Effects of microstructural variables on the deformation behaviour of dual-phase steel. Mater. Sci. Eng. A. 1995, 190(1–2): 55

[52] Y.Y. Yang, S. Zhang, P. Huang, and F. Wang, Phase transformation-induced strengthening and multistage strain hardening in double-gradient-structured high-entropy alloys, Appl. Phys. A, 128(2022), No. 4, art. No. 258.

[53] Wu BB, Wang ZQ, Wang XL, Xu WS, Shang CJ, Misra RDK. Toughening of martensite matrix in high strength low alloy steel: Regulation of variant pairs. Mater. Sci. Eng. A. 2019, 759: 430

[54] J. Wang, W. Li, X.D. Zhu, and L.Q. Zhang, Effect of martensite morphology and volume fraction on the low-temperature impact toughness of dual-phase steels, Mater. Sci. Eng. A, 832(2022), art. No. 142424.

[55] H.F. Li, P. Zhang, R.T. Qu, and Z.F. Zhang, The minimum energy density criterion for the competition between shear and flat fracture, Adv. Eng. Mater., 20(2018), No. 8, art. No. 1800150.

[56] Reynolds WT, Liu SK, Li FZ, Hartfield S, Aaronson HI. An investigation of the generality of incomplete transformation to bainite in Fe–C–X alloys. Metall. Trans. A. 1990, 21(6): 1479

[57] Dmitrieva O, Ponge D, Inden G, et al. . Chemical gradients across phase boundaries between martensite and austenite in steel studied by atom probe tomography and simulation. Acta Mater.. 2011, 59(1): 364

[58] S.W. Zhang, Y.D. Wang, M.H. Zhu, Z.J. Zhang, P.L. Nie, and Z.G. Li, Relationships among Charpy impact toughness, microstructure and fracture behavior in 10CrNi3MoV steel weld joint, Mater. Lett., 281(2020), art. No. 128328.

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