Effect of Superheat on Integral Morphology Characteristics of Solidification Structure and Permeability in Bearing Steel Billet

doi:10.11900/0412.1961.2020.00274

Acta Metall Sin

2021, Vol. 57

Issue (5): 586-594 DOI: 10.11900/0412.1961.2020.00274

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Effect of Superheat on Integral Morphology Characteristics of Solidification Structure and Permeability in Bearing Steel Billet

CAO Jianghai¹^,², HOU Zibing¹^,²(

), GUO Zhongao¹^,², GUO Dongwei¹^,², TANG Ping¹^,²

^1.College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
^2.Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials, Chongqing University, Chongqing, 400044, China

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CAO Jianghai, HOU Zibing, GUO Zhongao, GUO Dongwei, TANG Ping. Effect of Superheat on Integral Morphology Characteristics of Solidification Structure and Permeability in Bearing Steel Billet. Acta Metall Sin, 2021, 57(5): 586-594.

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Abstract

As a typical bearing steel, GCr15 steel tends to solidify over a wide temperature range during casting because of its high carbon content. The size of the mushy zone is relatively large, causing macrosegregation and porosity defects in bearing steel. The morphology of the solidification structure plays an important role in governing macrosegregation severity. Solidification structures have conventionally been characterized by measuring the primary or secondary dendrite arm spacing in a dendritic network, but these measures do not adequately describe the branched appearance of secondary and tertiary arms. In this work, fractal dimension and specific surface area have been introduced, and the solidification structure integral morphology characteristics of different locations in the continuous casting billet of GCr15 bearing steel have been quantitatively investigated. Then, the permeability of the interdendritic channels were calculated based on fractal dimension and specific surface area. The size of the billets was 220 mm × 220 mm, and the sampling location was in the cross section of the billet. Two superheats (20 and 35^oC) were considered for studying the integral characteristics of the solidification structure. First, fractal dimension can describe the self-similar complexity of the solidification structure, and specific surface area can describe dendritic coarsening. Second, it was determined that the fractal dimension was larger and the specific surface area was smaller at 35^oC superheat compared with 20^oC superheat. This indicates that the self-similar complexity of dendrites is larger, and the dendrite coarsening is more significant at high superheating. Finally, the permeability in the equiaxed grain zone calculated using fractal dimension and specific surface area is lower at 20^oC superheat. The smaller the permeability, the greater the flow resistance of the liquid, which is more conducive to the control of the macrosegregation defects. In addition, to effectively restrain the formation of macrosegregation defects at high superheat, the cooling rate in the equiaxed grains zone should increase by adjusting the process parameters under isothermal solidification conditions.

Key words: superheat solidification structure fractal dimension specific surface area permeability bearing steel

Received: 22 July 2020

ZTFLH:

TG113.12

Fund: United Funds between National Natural Science Foundation and Baowu Steel Group Corporation Limited of China(U1860101);Chongqing Fundamental Research and Cutting-Edge Technology Funds(cstc2017jcyjAX0019)

About author: HOU Zibing, associate professor, Tel: (023)65105202, E-mail: houzibing@cqu.edu.cn

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	Jianghai CAO
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	Zhongao GUO
	Dongwei GUO
	Ping TANG

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https://www.ams.org.cn/EN/10.11900/0412.1961.2020.00274 OR https://www.ams.org.cn/EN/Y2021/V57/I5/586

Fig.1 Schematic of sampling locations in cross section of billet (unit: mm)

Fig.2 Macrostructures of samples 1#-20# (a-t) at different locations of billet under 20^oC superheat

Fig.3 Macrostructures of samples 1#-20# (a-t) at different locations of billet under 35^oC superheat

Fig.4 Calculation process of fractal dimension in sample 1# under 20^oC superheat

Table 1 Fractal dimensions (D) and corresponding R² at different locations under 20 and 35^oC superheats

Fig.5 Fractal dimensions at different locations under 20 and 35^oC superheats

Fig.6 Specific surface areas at different locations under 20 and 35^oC superheats

Fig.7 Effects of superheat on fractal dimension (a) and specific surface area (b)

Fig.8 Relationship between fractal dimension and specific surface area

Fig.9 Permeability in equiaxed grains zone

1	Pickering E J. Macrosegregation in steel ingots: The applicability of modelling and characterisation techniques [J]. ISIJ Int., 2013, 53: 935
2	Choudhary S K, Ganguly S. Morphology and segregation in continuously cast high carbon steel billets [J]. ISIJ Int., 2007, 47: 1759
3	Mayer F, Wu M, Ludwig A. On the formation of centreline segregation in continuous slab casting of steel due to bulging and/or feeding [J]. Steel Res. Int., 2010, 81: 660
4	Flemings M C. Our understanding of macrosegregation: Past and present [J]. ISIJ Int., 2000, 40: 833
5	Zhong X T, Rowenhorst D J, Beladi H, et al. The five-parameter grain boundary curvature distribution in an austenitic and ferritic steel [J]. Acta Mater., 2017, 123: 136
6	Bisang U, Bilgram J H. The fractal dimension of xenon dendrites [J]. J. Cryst. Growth, 1996, 166: 207
7	González-Cinca R, Ramírez-Piscina L. Numerical study of the shape and integral parameters of a dendrite [J]. Phys. Rev., 2004, 70E: 051612
8	Mandelbrot B B. The Fractal Geometry of Nature [M]. New York: Freeman Press, 1982: 206
9	Mandelbrot B B. How long is the coast of Britain? Statistical self-similarity and fractional dimension [J]. Science, 1967, 156: 636
10	Zaiser M, Bay K, Hähner P. Fractal analysis of deformation-induced dislocation patterns [J]. Acta Mater., 1999, 47: 2463
11	Chang Q, Chen D L, Ru H Q, et al. Three-dimensional fractal analysis of fracture surfaces in titanium-iron particulate reinforced hydroxyapatite composites: Relationship between fracture toughness and fractal dimension [J]. J. Mater. Sci., 2011, 46: 6118
12	Kobayashi S, Maruyama T, Tsurekawa S, et al. Grain boundary engineering based on fractal analysis for control of segregation-induced intergranular brittle fracture in polycrystalline nickel [J]. Acta Mater., 2012, 60: 6200
13	Long Q Y, Wen Y H, Zhu Z, et al. Sierpinski fractal description of the martensitic transformation [J]. Philos. Mag., 1993, 68A: 885
14	Hou Z B, Cao J H, Chang Y, et al. Morphology characteristics of carbon segregation in die steel billet by ESR based on fractal dimension [J]. Acta Metall. Sin., 2017, 53: 769
	侯自兵, 曹江海, 常毅等. 基于分形维数的模具钢电渣重熔铸坯碳偏析形貌特征研究 [J]. 金属学报, 2017, 53: 769
15	Yang A M, Xiong Y H, Liu L. Fractal characteristics of dendrite and cellular structure in nickel-based superalloy at intermediate cooling rate [J]. Sci. Technol. Adv. Mater., 2001, 2: 101
16	Ishida H, Natsume Y, Ohsasa K. Characterization of dendrite morphology for evaluating interdendritic fluidity based on phase-field simulation [J]. ISIJ Int., 2009, 49: 37
17	Cao J H, Hou Z B, Guo D W, et al. Morphology characteristics of solidification structure in high-carbon steel billet based on fractal theory [J]. J. Mater. Sci., 2019, 54: 12851
18	Cao J H, Hou Z B, Guo D W, et al. Fractal morphology characteristics of solidification structure in electroslag remelting billet of die steel by ESR [J]. J. Iron Steel Res., 2019, 31: 286
	曹江海, 侯自兵, 郭东伟等. 模具钢电渣重熔铸坯凝固组织形貌的分形特征 [J]. 钢铁研究学报, 2019, 31: 286
19	Hou Z B, Jiang F, Cheng G G. Solidification structure and compactness degree of central equiaxed grain zone in continuous casting billet using cellular automaton-finite element method [J]. ISIJ Int., 2012, 52: 1301
20	Dubuc B, Quiniou J, Roques-Carmes C, et al. Evaluating the fractal dimension of profiles [J]. Phys. Rev., 1989, 39A: 1500
21	Genau A L, Freedman A C, Ratke L. Effect of solidification conditions on fractal dimension of dendrites [J]. J. Cryst. Growth, 2013, 363: 49
22	Kasperovich G, Genau A, Ratke L. Mushy zone coarsening in an AlCu₃₀ alloy accelerated by a rotating magnetic field [J]. Metall. Mater. Trans., 2011, 42A: 1657
23	Wang W, Hou Z B, Chang Y, et al. Effect of superheat on quality of central equiaxed grain zone of continuously cast bearing steel billet based on two-dimensional segregation ratio [J]. J. Iron Steel Res. Int., 2018, 25: 9
24	Zhu M F, Xing L K, Fang H, et al. Progresses in dendrite coarsening during solidification of alloys [J]. Acta Metall. Sin., 2018, 54: 789
	朱鸣芳, 邢丽科, 方辉等. 合金凝固枝晶粗化的研究进展 [J]. 金属学报, 2018, 54: 789
25	Tiller W A, Jackson K A, Rutter J W, et al. The redistribution of solute atoms during the solidification of metals [J]. Acta Metall., 1953, 1: 428
26	Aritaka E, Esaka H, Shinozuka K. Mechanism for complex morphology due to mechanical vibration [J]. ISIJ Int., 2016, 56: 1413
27	Whisler N J, Kattamis T Z. Dendritic coarsening during solidification [J]. J. Cryst. Growth, 1972, 15: 20
28	Marsh S P, Glicksman M E. Overview of geometric effects on coarsening of mushy zones [J]. Metall. Mater. Trans., 1996, 27A: 557
29	Hu H Q. Principle of Metal Solidification [M]. 2nd Ed., Beijing: Mechanical Industry Press, 2000: 210
	胡汉起. 金属凝固原理 [M]. 第2版,北京: 机械工业出版社, 2000: 210
30	Carman P C. Flow of Gases Through Porous Media [M]. London: Butterworth Scientific Publications, 1956: 10
31	Khajeh E, Maijer D M. Physical and numerical characterization of the near-eutectic permeability of aluminum-copper alloys [J]. Acta Mater., 2010, 58: 6334
32	Sun Z, Logé R E, Bernacki M. 3D finite element model of semi-solid permeability in an equiaxed granular structure [J]. Comput. Mater. Sci., 2010, 49: 158

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