Please wait a minute...
金属学报  2018, Vol. 54 Issue (5): 801-808    DOI: 10.11900/0412.1961.2017.00557
  金属材料的凝固专刊 本期目录 | 过刊浏览 |
纵向静磁场对定向凝固GCr15轴承钢柱状晶向等轴晶转变的影响
侯渊, 任忠鸣(), 王江, 张振强, 李霞
上海大学省部共建高品质特殊钢冶金与制备国家重点实验室 上海 200072
Effect of Longitudinal Static Magnetic Field on the Columnar to Equiaxed Transition in Directionally Solidified GCr15 Bearing Steel
Yuan HOU, Zhongming REN(), Jiang WANG, Zhenqiang ZHANG, Xia LI
State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072, China
引用本文:

侯渊, 任忠鸣, 王江, 张振强, 李霞. 纵向静磁场对定向凝固GCr15轴承钢柱状晶向等轴晶转变的影响[J]. 金属学报, 2018, 54(5): 801-808.
Yuan HOU, Zhongming REN, Jiang WANG, Zhenqiang ZHANG, Xia LI. Effect of Longitudinal Static Magnetic Field on the Columnar to Equiaxed Transition in Directionally Solidified GCr15 Bearing Steel[J]. Acta Metall Sin, 2018, 54(5): 801-808.

全文: PDF(8049 KB)   HTML
摘要: 

进行了外加纵向静磁场下GCr15轴承钢的定向凝固实验,考察了纵向静磁场对试样凝固过程中柱状枝晶向等轴枝晶转变(columnar to equiaxed transition,CET)的影响。结果表明,在温度梯度(104 K/cm)和抽拉速率(20 μm/s)一定时,随着磁场强度的增加(0~5 T),试样棒边缘柱状枝晶的生长逐渐地遭到破坏,从而发生不同程度的CET;当磁场强度和温度梯度分别为4 T和104 K/cm时,在较低抽拉速率(5 μm/s)下,试样的凝固组织发生了完全CET;在试样发生完全CET后,其合金元素分布趋于均匀。结合数值模拟,可将这些现象归结为纵向静磁场与热电流相互作用产生的热电磁力对枝晶和熔体的作用所致。

关键词 GCr15轴承钢纵向静磁场定向凝固偏析柱状晶向等轴晶转变    
Abstract

Columnar to equiaxed transition (CET) generating a fine-grain structure of GCr15 bearing steel with the homogeneity of the solute contents and the rather small amount of internal defects is often desired in solidification processes. In recent years much attention has been paid to the effect of static magnetic fields on the CET of Al base alloys, Pb-Sn alloys and Ni base superalloys. However, there are few papers to investigate the effect of static magnetic fields on the CET of GCr15 bearing steel. The present work investigates how longitudinal static magnetic fields affect the CET in directionally solidified GCr15 bearing steel. Experimental results show that columnar dendrites degenerate and transform into equiaxed dendrites at the edge of the sample as the longitudinal static magnetic field increases at pulling rate of 20 μm/s and temperature gradient of 104 K/cm. The dendritic morphology without the longitudinal static magnetic field is regular and columnar at pulling rate of 5 and 50 μm/s and temperature gradient of 104 K/cm. When the 4 T longitudinal static magnetic field is applied, the dendritic morphology is still regular and columnar at pulling rate of 50 μm/s and temperature gradient of 104 K/cm. However, the CET occurs at low pulling rate of 5 μm/s and temperature gradient of 104 K/cm. This phenomenon is simultaneously accompanied by more uniformly distributed alloying elements. The corresponding numerical simulations verify that the thermoelectric (TE) magnetic force is induced by the interaction between the longitudinal static magnetic field and TE current. Owing to TE magnetic force localized into the root of the dendrite, the dendritic fragments detach from the primary dendrites. Then the TE magnetic convection induced by TE magnetic force acting on the melt transports the fragments from the interdendritic spacing to the region ahead of columnar dendrites. It can be deduced from above phenomena that the TE magnetic force leads to the CET under the longitudinal static magnetic field.

Key wordsGCr15 bearing steel    longitudinal static magnetic field    directional solidification    microsegregation    columnar to equiaxed transition
收稿日期: 2017-12-25     
ZTFLH:  TG146  
基金资助:资助项目 国家自然科学基金项目Nos.U1560202、51604171、51690162,上海市科委项目No.17JC1400602及上海商用航空发动机联合创新项目Nos.AR910 和AR911
作者简介:

作者简介 侯 渊,男,1985年生,博士生

图1  纵向静磁场下Bridgman 定向凝固装置示意图
图2  温度梯度和抽拉速率分别为104 K/cm和20 μm/s时GCr15轴承钢在不同纵向静磁场强度下固/液界面处纵截面的组织
图3  温度梯度为104 K/cm和有无4 T磁场作用时GCr15轴承钢在不同抽拉速率下固/液界面处纵截面的组织
图4  在温度梯度和抽拉速率分别为104 K/cm和5 μm/s时,有无4 T磁场时GCr15轴承钢在固/液界面下15 mm处Cr元素的径向分布
Parameter Unit Value in solid Value in liquid
Absolute thermoelectric power S VK-1 -1×10-6 -4×10-6
Dynamic viscosity μ Pas - 5.5×10-3
Electrical conductivity σ Ω-1m-1 8.5×105 7.2×105
Density ρ kgm-3 7.4×103 7.02×103
Thermal conductivity λ Wm-1K-1 32.5 31.2
表1  GCr15轴承钢数值模拟的相关参数[32,33,34]
图5  在温度梯度和抽拉速率分别为104 K/cm和20 μm/s时,5 T纵向静磁场下GCr15轴承钢单个柱状枝晶的几何模型、热电流分布和作用于枝晶上的应力的分布
图6  在温度梯度和抽拉速率分别为104 K/cm和50 μm/s时,5 T纵向静磁场下GCr15轴承钢柱状枝晶阵列的几何模型、热电流分布、热电磁对流的分布和糊状区内不同z轴位置x-y平面上热电磁对流的分布
图7  有无纵向静磁场下定向凝固GCr15轴承钢柱状枝晶向等轴枝晶转变(CET)示意图
Parameter Unit Value
Heterogeneous nuclei density N0 m-3 9×108
Supercooling necessary for
nucleation ΔTN
K 1.5
Diffusion coefficient D m2s-1 4.79×10-9
Partition coefficient k - 0.34
Liquidus slope m K%-1 -78
Gibbs-Thomson parameter Γ Km 1.9×10-7
表2  计算GCr15轴承钢CET图的相关参数[31,32,42]
图3  有无纵向静磁场下定向凝固GCr15轴承钢CET图
[1] Bhadeshia H K D H. Steels for bearings[J]. Prog. Mater. Sci., 2012, 57: 268
[2] Dong Z Q, Jiang B, Mei Z, et al.Effect of carbide distribution on the grain refinement in the steel for large-size bearing ring[J]. Steel Res. Int., 2016, 87: 745
[3] Qiu H, Wang L N, Hanamura T, et al.Physical interpretation of grain refinement-induced variation in fracture mode in ferritic steel[J]. ISIJ Int., 2013, 53: 382
[4] Walker P F F, Kerrigan A, Green M, et al. Modelling of micro-segregation in a 1C-1.5Cr type bearing steel[J]. Bear. Steel Technol., 2015, 10: 54
[5] Grong O, Kolbeinsen L, Van Der Eijk C, et al. Microstructure control of steels through dispersoid metallurgy using novel grain refining alloys[J]. ISIJ Int., 2014, 46: 824
[6] Kivi? M, Holappa L, Iung T.Addition of dispersoid titanium oxide inclusions in steel and their influence on grain refinement[J]. Metall. Mater. Trans., 2010, 41B: 1194
[7] Sasaki M, Ohsasa K, Kudoh M, et al.Refinement of austenite grain in carbon steel by addition of titanium and boron[J]. ISIJ Int., 2008, 48: 340
[8] Watanabe T, Shiroki M, Yanagisawa A, et al.Improvement of mechanical properties of ferritic stainless steel weld metal by ultrasonic vibration[J]. J. Mater. Process. Technol., 2010, 210: 1646
[9] Lu J Z, Luo K Y, Zhang Y K, et al.Grain refinement mechanism of multiple laser shock processing impacts on ANSI 304 stainless steel[J]. Acta Mater., 2010, 58: 5354
[10] Abbasi-Khazaei B, Ghaderi S.A novel process in semi-solid metal casting[J]. J. Mater. Sci. Technol., 2012, 28: 946
[11] Li Q S, Song C J, Li H B, et al.Effect of pulsed magnetic field on microstructure of 1Cr18Ni9Ti austenitic stainless steel[J]. Mater. Sci. Eng., 2007, A466: 101
[12] Spitzer K H, Dubke M, Schwerdtfeger K.Rotational electromagnetic stirring in continuous casting of round strands[J]. Metall. Mater. Trans., 1986, 17B: 119
[13] Galindo V, Grants I, Lantzsch R, et al.Numerical and experimental modeling of the melt flow in a traveling magnetic field for vertical gradient freeze crystal growth[J]. J. Cryst. Growth, 2007, 303: 258
[14] Hernández F C R, Sokolowski J H. Comparison among chemical and electromagnetic stirring and vibration melt treatments for Al-Si hypereutectic alloys[J]. J. Alloys Compd., 2006, 426: 205
[15] Nafisi S, Emadi D, Shehata M T, et al.Effects of electromagnetic stirring and superheat on the microstructural characteristics of Al-Si-Fe alloy[J]. Mater. Sci. Eng., 2006, A432: 71
[16] Lu D H, Jiang Y H, Guan G S, et al.Refinement of primary Si in hypereutectic Al-Si alloy by electromagnetic stirring[J]. J. Mater. Process. Technol., 2007, 189: 13
[17] Chen Z, Wen X L, Chen C L.Fluid flow and microstructure formation in a rotating magnetic field during the directional solidification process[J]. J. Alloys Compd., 2010, 491: 395
[18] Campanella T, Charbon C, Rappaz M.Grain refinement induced by electromagnetic stirring: A dendrite fragmentation criterion[J]. Metall. Mater. Trans., 2004, 35A: 3201
[19] Harada H, Toh T, Ishii T, et al.Effect of magnetic field conditions on the electromagnetic braking efficiency[J]. ISIJ Int., 2001, 41: 1236
[20] Shercliff J A.Thermoelectric magnetohydrodynamics in closed containers[J]. Phys. Fluid., 1979, 22: 635
[21] Li X, Gagnoud A, Ren Z M, et al.Investigation of thermoelectric magnetic convection and its effect on solidification structure during directional solidification under a low axial magnetic field[J]. Acta Mater., 2009, 57: 2180
[22] Lehmann P, Moreau R, Camel D, et al.Modification of interdendritic convection in directional solidification by a uniform magnetic field[J]. Acta Mater., 1998, 46: 4067
[23] Dold P, Szofran F R, Benz K W.Thermoelectromagnetic convection in vertical Bridgman grown germanium-silicon[J]. J. Cryst. Growth, 2006, 291: 1
[24] Li X, Gagnoud A, Fautrelle Y, et al.Dendrite fragmentation and columnar-to-equiaxed transition during directional solidification at lower growth speed under a strong magnetic field[J]. Acta Mater., 2012, 60: 3321
[25] Li X, Ren Z M, Shen Y, et al.Effect of thermoelectric magnetic force on the array of dendrites during directional solidification of Al-Cu alloys in a high magnetic field[J]. Philos. Mag. Lett., 2012, 92: 675
[26] Li X, Fautrelle Y, Zaidat K, et al.Columnar-to-equiaxed transitions in Al-based alloys during directional solidification under a high magnetic field[J]. J. Cryst. Growth, 2010, 312: 267
[27] Yu J B, Du D F, Ren Z M, et al.Influence of an axial magnetic field on microstructures and alignment in directionally solidified Ni-based superalloy[J]. ISIJ Int., 2017, 57: 337
[28] Kato T, Jones H, Kirkwood D H.Segregation and eutectic formation in solidification of Fe-1C-1.5Cr steel[J]. Mater. Sci. Technol., 2003, 19: 1070
[29] Baltaretu F, Wang J, Letout S, et al.Thermoelectric effects on electrically conducting particles in liquid metal[J]. Magnetohydrodynamics, 2015, 51: 45
[30] Wang J, Fautrelle Y, Nguyen-Thi H, et al.Thermoelectric magnetohydrodynamic flows and their induced change of solid-liquid interface shape in static magnetic field-assisted directional solidification[J]. Metall. Mater. Trans., 2017, 47A: 1
[31] Kurz W, Fisher D J.Fundamentals of Solidification[M]. 3rd Ed., Switzerland: Trans Tech Publications. Ltd., 1992: 80
[32] Wang W L, Luo S, Zhu M Y.Dendritic growth of high carbon iron-based alloy under constrained melt flow[J]. Comput. Mater. Sci., 2014, 95: 136
[33] Taniguchi S, Brimacombe J K.Application of pinch force to the separation of inclusion particles from liquid steel[J]. ISIJ Int., 1994, 34: 722
[34] Enderby J E, Dupree B C.The thermoelectric power of liquid Fe, Co and Ni[J]. Philos. Mag., 1977, 35: 791
[35] Hellawell A, Liu S, Lu S Z.Dendrite fragmentation and the effects of fluid flow in castings[J]. JOM, 1997, 49(3): 18
[36] Zimmermann G, Pickmann C, Hamacher M, et al.Fragmentation-driven grain refinement in directional solidification of AlCu10wt-% alloy at low pulling speeds[J]. Acta Mater., 2017, 126: 236
[37] Flemings M C.Behavior of metal alloys in the semisolid state[J]. Metall. Trans., 1991, 22B: 269
[38] Hunt J D.Steady state columnar and equiaxed growth of dendrites and eutectic[J]. Mater. Sci. Eng., 1984, 65: 75
[39] Cai B, Wang J, Kao A, et al.4D synchrotron X-ray tomographic quantification of the transition from cellular to dendrite growth during directional solidification[J]. Acta Mater., 2016, 117: 160
[40] Ruvalcaba D, Mathiesen R H, Eskin D G, et al.In situ observations of dendritic fragmentation due to local solute-enrichment during directional solidification of an aluminum alloy[J]. Acta Mater., 2007, 55: 4287
[41] Ananiev S, Nikrityuk P, Eckert K.Dendrite fragmentation by catastrophic elastic remelting[J]. Acta Mater., 2009, 57: 657
[42] Luo S, Zhu M Y, Louhenkilpi S.Numerical simulation of solidification structure of high carbon steel in continuous casting using cellular automaton method[J]. ISIJ Int., 2012, 52: 823
[1] 张健, 王莉, 谢光, 王栋, 申健, 卢玉章, 黄亚奇, 李亚微. 镍基单晶高温合金的研发进展[J]. 金属学报, 2023, 59(9): 1109-1124.
[2] 马德新, 赵运兴, 徐维台, 王富. 重力对高温合金定向凝固组织的影响[J]. 金属学报, 2023, 59(9): 1279-1290.
[3] 常松涛, 张芳, 沙玉辉, 左良. 偏析干预下体心立方金属再结晶织构竞争[J]. 金属学报, 2023, 59(8): 1065-1074.
[4] 刘继浩, 周健, 武会宾, 马党参, 徐辉霞, 马志俊. 喷射成形M3高速钢偏析成因及凝固机理[J]. 金属学报, 2023, 59(5): 599-610.
[5] 苏震奇, 张丛江, 袁笑坦, 胡兴金, 芦可可, 任维丽, 丁彪, 郑天祥, 沈喆, 钟云波, 王晖, 王秋良. 纵向静磁场下单晶高温合金定向凝固籽晶回熔界面杂晶的形成与演化[J]. 金属学报, 2023, 59(12): 1568-1580.
[6] 张利民, 李宁, 朱龙飞, 殷鹏飞, 王建元, 吴宏景. 交流电脉冲对过共晶Al-Si合金中初生Si相偏析的作用机制[J]. 金属学报, 2023, 59(12): 1624-1632.
[7] 陈学双, 黄兴民, 刘俊杰, 吕超, 张娟. 一种含富锰偏析带的热轧临界退火中锰钢的组织调控及强化机制[J]. 金属学报, 2023, 59(11): 1448-1456.
[8] 李彦强, 赵九洲, 江鸿翔, 何杰. Pb-Al合金定向凝固组织形成过程[J]. 金属学报, 2022, 58(8): 1072-1082.
[9] 郭东伟, 郭坤辉, 张福利, 张飞, 曹江海, 侯自兵. 基于二次枝晶间距变化特征的连铸方坯CET位置判断新方法[J]. 金属学报, 2022, 58(6): 827-836.
[10] 李亚敏, 张瑶瑶, 赵旺, 周生睿, 刘洪军. CuInconel 718合金Nb偏析影响机理的第一性原理研究[J]. 金属学报, 2022, 58(2): 241-249.
[11] 陈瑞润, 陈德志, 王琪, 王墅, 周哲丞, 丁宏升, 傅恒志. Nb-Si基超高温合金及其定向凝固工艺的研究进展[J]. 金属学报, 2021, 57(9): 1141-1154.
[12] 冯苗苗, 张红伟, 邵景霞, 李铁, 雷洪, 王强. 耦合热力学相变路径预测Fe-C包晶合金宏观偏析[J]. 金属学报, 2021, 57(8): 1057-1072.
[13] 郭中傲, 彭治强, 柳前, 侯自兵. 高碳钢连铸坯大区域C元素分布不均匀度[J]. 金属学报, 2021, 57(12): 1595-1606.
[14] 张壮, 李海洋, 周蕾, 刘华松, 唐海燕, 张家泉. 齿轮钢铸态点状偏析及其在热轧棒材中的演变[J]. 金属学报, 2021, 57(10): 1281-1290.
[15] 张勇, 李鑫旭, 韦康, 韦建环, 王涛, 贾崇林, 李钊, 马宗青. 三联熔炼GH4169合金大规格铸锭与棒材元素偏析行为[J]. 金属学报, 2020, 56(8): 1123-1132.