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Morphology Characteristics of Carbon Segregation in Die Steel Billet by ESR Based on Fractal Dimension |
Zibing HOU(),Jianghai CAO,Yi CHANG,Wei WANG,Han CHEN |
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China |
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Cite this article:
Zibing HOU,Jianghai CAO,Yi CHANG,Wei WANG,Han CHEN. Morphology Characteristics of Carbon Segregation in Die Steel Billet by ESR Based on Fractal Dimension. Acta Metall Sin, 2017, 53(7): 769-777.
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Abstract Macro/semi-macro carbon segregation plays a key role for improving the steel product quality. Based on macrostructure qualitative rating comparison and element macro content analysis, the segregation extent has been controlled at different levels by the existing technologies, but there is an obvious shortcoming on segregation morphology description. Nowadays, delicacy control is demanded for higher quality requirement, especially for the production of high-quality H13 die steel by electro-slag remelting (ESR) technique. In this work, as to segregation point morphology, fractal dimension is introduced, and segregation characteristics of different locations in the ESR billet are quantitatively investigated in terms of area, number and outline morphology. The size of the billet is 160 mm×160 mm, and the sampling location in the central plane of billet. Two melting rates (350 and 400 kg/h) are considered for studying essential characteristics of segregation. Firstly, it is shown that the whole segregation extent in the billet is mostly influenced by the large segregation point (e.g., the area is larger than 0.1 mm2). The segregation ratio will be increased when increasing the number or area of the large segregation point. Secondly, it is found that fractal is a very important characteristic of the segregation point morphology in the billet. Moreover, fractal dimension can be used as a criterion for measuring the dispersion degree of the segregation. The dispersion degree will be increased when increasing the corresponding fractal dimension, and the large segregation point will be disintegrated by the small segregation point. Finally, the fractal dimensions in the columnar-equiaxed transition area and the solidifying end equiaxed area are less than the value of other locations. In addition, more researches are needed for accurately obtaining the influence factors of fractal dimensions of segregation point in the future.
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Received: 26 September 2016
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Fund: Supported by National Natural Science Foundation of China (No.51504047) and Fundamental Research Funds for the Central Universities (No.CDJPY14130001) |
[1] | Li Z B.Electroslag Metallurgy Theory and Practice [M]. Beijing: Metallurgical Industry Press, 2010: 76 | [1] | (李正邦. 电渣冶金的理论与实践 [M]. 北京: 冶金工业出版社, 2010: 76) | [2] | Kubin M, Scheriau A, Knabl M, et al.Electro slag rapid remelting (ESRR?)——A novel technology for the production of high-quality, near-net-shaped billets and blooms [A]. 2014 AISTech Conference Proceedings[C]. Indianapolis: Association for Iron and Steel Technology, 2014: 1405 | [3] | Wang M, Ma D S, Liu Z T, et al.Effect of Nb on segregation, primary carbides and toughness of H13 steel[J]. Acta Metall. Sin., 2014, 50: 285 | [3] | (王明, 马党参, 刘振天等. Nb对芯棒用H13钢偏析、液析碳化物及力学性能的影响[J]. 金属学报, 2014, 50: 285) | [4] | Flemings M C.Our understanding of macrosegregation: Past and present[J]. ISIJ Int., 2000, 40: 833 | [5] | Lesoult G. Macrosegregation in steel strands and ingots: Characterisation, formation and consequences [J]. Mater. Sci. Eng., 2005, A413-414: 19 | [6] | Cai Z Z, Zhu M Y.Microsegregation of solute elements in solidifying mushy zone of steel and its effect on longitudinal surface cracks of continuous casting strand[J]. Acta Metall. Sin., 2009, 45: 949 | [6] | (蔡兆镇, 朱苗勇. 钢凝固两相区溶质元素的微观偏析及其对连铸坯表面纵裂纹的影响[J]. 金属学报, 2009, 45: 949) | [7] | Han Z Q, Cai K K.Study on a mathematical model of microsegregation in continuously cast slab[J]. Acta Metall. Sin., 2000, 36: 869 | [7] | (韩志强, 蔡开科. 连铸坯中微观偏析的模型研究[J]. 金属学报, 2000, 36: 869) | [8] | Yuan X F, Sun S Q.Introduce the standard figure of GB/T 1979-2001 structure steel macrostructure and defect[J]. Metall. Standard. Qual., 2002, 40(6): 8 | [8] | (袁辛芳, 孙时秋. GB/T 1979-2001 结构钢低倍组织缺陷评级图介绍[J]. 冶金标准化与质量, 2002, 40(6): 8) | [9] | Cai K K.Quality Control of Continuously Cast Steel [M]. Beijing: Metallurgical Industry Press, 2010: 283 | [9] | (蔡开科. 连铸坯质量控制 [M]. 北京: 冶金工业出版, 2010: 283) | [10] | Mandelbrot B.How long is the coast of Britain? Statistical self-similarity and fractional dimension[J]. Science, 1967, 156: 636 | [11] | Mandelbrot B B.The Fractal Geometry of Nature[M]. San Francisco: Freeman, 1982: 206 | [12] | Chen Y, Chen L.Fractal Geometry [M]. 2nd Ed., Beijing: Seismological Press, 2005: 1 | [12] | (陈颙, 陈凌. 分形几何学 [M]. 第2版, 北京: 地震出版社, 2005: 1) | [13] | Liu D J.Fractal Theory Applied to Chemical Industry [M]. Beijing: Chemical Industry Press, 2006: 13 | [13] | (刘代俊. 分形理论在化学工程中的应用 [M]. 北京: 化学工业出版社, 2006: 13) | [14] | Xie H P, Chen Z D.The method of fractal geometry for quantitative analysis of fracture surface[J]. Eng. Mech., 1989, 6(4): 1 | [14] | (谢和平, 陈至达. 断口定量分析的分形几何方法[J]. 工程力学, 1989, 6(4): 1) | [15] | Zhou Y H, Hu Z L, Jie W Q.Solidifying Technology [M]. Beijing: Mechanical Industry Press, 1998: 188 | [15] | (周尧和, 胡壮麟, 介万奇. 凝固技术[M]. 北京: 机械工业出版社, 1998: 188) | [16] | Sun L L, Dong L K, Zhang J S, et al.Fractal analysis of directional solidification behaviour of Ni-base superalloy[J]. Acta Metall. Sin., 1993, 29: A115 | [16] | (孙力玲, 董连科, 张济山等. 高温合金定向凝固行为的分形分析[J]. 金属学报, 1993, 29: A115) | [17] | Liu J M, Zhou Y H, Shang B L.On fractal of silicon-branching clusters for Al-Si eutectic growth[J]. Mater. Sci. Progr., 1990, 4: 398 | [17] | (刘俊明, 周尧和, 商宝禄. Al-Si共晶生长过程中Si相分枝的分维特征[J]. 材料科学进展, 1990, 4: 398) | [18] | Sun L L, Dong L K, Zhang J H, et al.Fractal analyses of MC in a directionally solidified nickel-base superalloy[J]. Acta Metall. Sin., 1993, 29: A388 | [18] | (孙力玲, 董连科, 张静华等. 镍基高温合金定向凝固过程中MC型碳化物的分形分析[J]. 金属学报, 1993, 29: A388) | [19] | Liu Z, Xu L N, Yu Z F, et al.Research on the morphology and fractal dimension of primary phase in semisolid A356-La aluminum alloy by electro-magnetic stirring[J]. Acta Metall. Sin., 2016, 52: 689 | [19] | (刘政, 徐丽娜, 余昭福等. 电磁场作用下半固态A356-La铝合金初生相形貌及分形维数的研究[J]. 金属学报, 2016, 52: 689) | [20] | Yamamoto M, Narita I, Miyahara H.Fractal analysis of solidification microstructure of high carbon high alloy cast roll manufactured by centrifugal casting[J]. Tetsu Hagané, 2013, 99: 72 | [20] | (山本昌宏,成田一人,宮原広郁. 遠心鋳造した高炭素高合金鋳鉄ロールの 凝固組織のフラクタル解析[J]. 鉄と鋼,2013, 99: 72) | [21] | Satou F, Esaka H, Shinozuka K.Effect of size and morphology of equiaxed grains on macroscopic segregation[J]. Tetsu Hagané, 2013, 99: 108 | [21] | (佐藤文人,江阪久雄,篠塚計. マクロ偏析生成に及ぼす凝固組織サイズおよび形態の影響[J]. 鉄と鋼,2013, 99: 108) | [22] | Sugawara R, Itoh T, Natsume Y, et al.Prediction of dendrite morphology in Fe-base-ternary alloys and evaluation of permeability[J]. Tetsu Hagané, 2013, 99: 126 | [22] | (菅原諒介,伊藤利久,棗千修,大笹憲一. 鉄基三元系合金のデンドライト形態予測および透過率の評価[J]. 鉄と鋼,2013, 99: 126) | [23] | 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 | [24] | Mullins W W, Sekerka R F.Stability of a planar interface during solidification of a dilute binary alloy[J]. J. Appl. Phys., 1964, 35: 444 | [25] | Trivedi R, Kurz W.Dendritic growth[J]. Int. Mater. Rev., 1994, 39: 49 | [26] | Li T, Chen G, Lin X, et al.Morphological evolution of solidification microstructure of binary alloy under stirring[J]. Acta Metall. Sin., 2006, 42: 577 | [26] | (李涛, 陈光, 林鑫等. 搅拌条件下二元合金凝固组织的形态演化[J]. 金属学报, 2006, 42: 577) |
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