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Effect of Tempering Time on Carbide Evolution and Mechanical Properties in a Fe-Cr-Ni-Mo High-Strength Steel |
Yubin DU1,2, Xiaofeng HU1( ), Haichang JIANG1, Desheng YAN1, Lijian RONG1 |
1 Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016, China 2 School of Materials Science and Engineering, University of Science and Technology of China,Shenyang 110016, China |
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Cite this article:
Yubin DU, Xiaofeng HU, Haichang JIANG, Desheng YAN, Lijian RONG. Effect of Tempering Time on Carbide Evolution and Mechanical Properties in a Fe-Cr-Ni-Mo High-Strength Steel. Acta Metall Sin, 2018, 54(1): 11-20.
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Abstract Fe-Cr-Ni-Mo steel is widely used in various industrial fields, such as water turbine in hydroelectric power station, pressure vessel and shipbuilding section etc. due to its excellent performance in strength and impact toughness. In order to fulfill the needs of high-strength and good toughness, the quenching and following tempering are often used for this kind of Fe-Cr-Ni-Mo steel. In particular, the carbide precipitation in the tempering process is the key to determine the strength and toughness. In this work, TEM and SEM were used to investigate the effect of tempering time (10, 20, 40 and 120 min) on carbide evolution and mechanical properties of Fe-Cr-Ni-Mo steel with different V contents (0, 0.08% and 0.14%, mass fraction) after quenched at 860 ℃ and following tempering at 610 ℃. The results show that some M7C3 type carbides precipitated along martensite lath boundaries in quenched 0V steel, but no carbide in the quenched 008V and 014V steels. As a result, the strength of 0V steel (2060 MPa) is higher than 008V and 014V (1906 and 1857 MPa, respectively). After tempering for 20 min, a small amount of M3C type carbides were found on the lath boundaries in 0V steel. With tempering time increasing, M3C will transform into M23C6 carbide gradually. Both M3C and M23C6 type carbides exhibited a large size in range from 150 nm to 300 nm which were unfavorable to strength. As a result, the tensile strength of 0V steel decreases from 1197 MPa to 1088 MPa when tempering time increases from 20 min to 120 min. As for the 008V and 014V steels tempered for 20min, there are not only M3C type carbides precipitated in the grain boundary, but also M2C type carbides found inside the grains. The size of both carbides is no larger than 80 nm. With increasing tempering time, the M3C will dissolve gradually and there will precipitate much more M6C and MC. Compared with coarse M3C, the finer M2C, M6C and MC have better precipitation strengthening effect and less deterioration of ductility and toughness. Therefore, with increasing tempering time the strengthes of 008V and 014V steels keep stable and the elongation and impact toughnesses increase gradually. This indicates that the excellent combination of strength and impact toughness can be obtained in 008V and 014V steels.
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Received: 14 June 2017
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[1] | Dong J, Zhou X S, Liu Y C, et al.Carbide precipitation in Nb-V-Ti microalloyed ultra-high strength steel during tempering[J]. Mater. Sci. Eng., 2017, A683: 215 | [2] | Rong Y H.Advanced Q-P-T steels with ultrahigh strength-high ductility[J]. Acta Metall. Sin., 2011, 47: 1483(戎咏华. 先进超高强度—高塑形Q-P-T钢[J]. 金属学报, 2011, 47: 1483) | [3] | Kuo K H, Jia C L.Crystallography of M23C6 and M6C precipitated in a low alloy steel[J]. Acta Metall., 1985, 33: 991 | [4] | Janovec J, Vyrostkova A, Svoboda M.Influence of tempering temperature on stability of carbide phases in 2.6Cr-0.7Mo-0.3V steel with various carbon content[J]. Metall. Mater. Trans., 1994, 25A: 267 | [5] | Stevens R A, Flewitt P E J. The dependence of creep rate on microstructure in a γ' strengthened superalloy[J]. Acta Metall., 1981, 29: 867 | [6] | Misra R D K, Jia Z, O'Malley R, et al. Precipitation behavior during thin slab thermomechanical processing and isothermal aging of copper-bearing niobium-microalloyed high strength structural steels: The effect on mechanical properties[J]. Mater. Sci. Eng., 2011, A528: 8772 | [7] | Zhou S, Zhang K, Wang Y, et al.High strength-elongation product of Nb-microalloyed low-carbon steel by a novel quenching-partitioning-tempering process[J]. Mater. Sci. Eng., 2011, A528: 8006 | [8] | Lee K H, Park S G, Kim M C, et al.Characterization of transition behavior in SA508 Gr.4N Ni-Cr-Mo low alloy steels with microstructural alteration by Ni and Cr contents[J]. Mater. Sci. Eng., 2011, A529: 156 | [9] | Lee B S, Kim M C, Yoon J H, et al.Characterization of high strength and high toughness Ni-Mo-Cr low alloy steels for nuclear application[J]. Int. J. Pres. Ves. Pip., 2010, 87: 74 | [10] | Mulholland M D, Seidman D N.Nanoscale Co-precipitation and mechanical properties of a high-strength low-carbon steel[J]. Acta Mater., 2011, 59: 1881 | [11] | Wen T, Hu X F, Song Y Y, et al.Effect of tempering temperature on carbide and mechanical properties in a Fe-Cr-Ni-Mo high-strength steel[J]. Acta Metall. Sin., 2014, 50: 447(温涛, 胡小锋, 宋元元等. 回火温度对一种Fe-Cr-Ni-Mo高强钢碳化物及其力学性能的影响[J]. 金属学报, 2014, 50: 447) | [12] | Wang L J, Cai Q W, Wu H B, et al.Effects of tempering temperature on the microstructure and mechanical properties of 1500 MPa grade steel directly quenched[J]. J. Univ. Sci. Technol. Beijing, 2010, 32: 1150(王立军, 蔡庆伍, 武会宾等. 回火温度对1500 MPa级直接淬火钢组织与性能的影响[J]. 北京科技大学学报, 2010, 32: 1150) | [13] | Liu Q D, Liu W Q, Wang Z M, et al.3D Atom probe characterization of carbides precipitated in the Nb-V microalloyed steel[J]. Acta Metall. Sin., 2008, 44: 786(刘庆冬, 刘文庆, 王泽民等. Nb-V微合金钢中碳化物析出的三维原子探针表征[J]. 金属学报, 2008, 44: 786) | [14] | Janovec J, Vyrostková A, Svoboda M, et al.Evolution of secondary phases in Cr-V low-alloy steels during aging[J]. Metall. Mater. Trans., 2004, 35A: 751 | [15] | Yan W, Zhu L, Sha W, et al.Change of tensile behavior of a high-strength low-alloy steel with tempering temperature[J]. Mater. Sci. Eng., 2009, A517: 369 | [16] | Vyrostková A, Kroupá A, Janovec J, et al.Carbide reactions and phase equilibria in low alloy Cr-Mo-V steels tempered at 773-993 K. Part I: Experimental measurements[J]. Acta Mater., 1998, 46: 31 | [17] | Thomson R C, Miller M K.Carbide precipitation in martensite during the early stages of tempering Cr-and Mo-containing low alloy steels[J]. Acta Mater., 1998, 46: 2203 | [18] | Wen T, Hu X F, Song Y Y, et al.Carbides and mechanical properties in a Fe-Cr-Ni-Mo high-strength steel with different V contents[J]. Mater. Sci. Eng., 2013, A588: 201 | [19] | Zhang S H.Alloy-Steel [M]. Beijing: Metallurgical Industry Press, 1981: 37(章守华.合金钢[M]. 北京: 冶金工业出版社, 1981: 37) | [20] | Wen T.Study on high-strength and high-toughness Fe-Cr-Ni-Mo based steel for gas cylinder application [D]. Shenyang: Institute of Metal Research, Chinese Academy of Sciences, 2014(温涛. 气瓶用高强高韧Fe-Cr-Ni-Mo系合金钢的研究 [D]. 沈阳: 中国科学院金属研究所, 2014) | [21] | Inoue A, Masumoto T.Carbide reactions (M3C→M7C3→M23C6→M6C) during tempering of rapidly solidified high carbon Cr-W and Cr-Mo steels[J]. Metall. Trans., 1980, 11A: 739 | [22] | Janovec J, Svoboda M, Vyrostková A, et al.Time-temperature-precipitation diagrams of carbide evolution in low alloy steels[J]. Mater. Sci. Eng., 2005, A402: 288 | [23] | Zhang Y.Application of phase equilibrium thermodynamic method in alloy design for high carbon alloy steel with ultra fine carbides [D]. Dalian: Dalian Maritime University, 2007(张洋. 相平衡热力学方法在超细碳化物高碳合金钢合金设计中的应用 [D]. 大连: 大连海事大学, 2007) | [24] | Xie Z J, Ma X P, Shang C J, et al.Nano-sized precipitation and properties of a low carbon niobium micro-alloyed bainitic steel[J]. Mater. Sci. Eng., 2015, A641: 37 | [25] | Trabadelo V, Giménez S, Gómez-Acebo T, et al.Critical assessment of computational thermodynamics in the alloy design of PM high speed steels[J]. Scr. Mater., 2005, 53: 287 | [26] | Schneider A, Inden G.Simulation of the kinetics of precipitation reactions in ferritic steels[J]. Acta Mater., 2005, 53: 519 | [27] | Asadabad M A, Kheirandish S, Novinrooz A J.Tempering behavior of 4.5Cr-2W-0.25V steel[J]. J. Iron Steel Res. Int., 2010, 17: 57 | [28] | Chen J D, Mo W L, Wang P.Effects of tempering temperature on the impact toughness of steel 42CrMo[J]. Acta Metall. Sin., 2012, 48: 1186(陈俊丹, 莫文林, 王培. 回火温度对42CrMo钢冲击韧性的影响[J]. 金属学报, 2012, 48: 1186) |
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