冷却速率对包晶钢凝固过程中包晶转变收缩的影响
收稿日期: 2018-12-19
修回日期: 2019-03-25
网络出版日期: 2019-05-22
基金资助
国家自然科学基金委员会-中国宝武钢铁集团有限公司钢铁联合研究基金项目(U1760103)
Influence of Cooling Rate on the Contraction of Peritectic Transformation During Solidification of Peritectic Steels
Received date: 2018-12-19
Revised date: 2019-03-25
Online published: 2019-05-22
Supported by
National Natural Science Foundation of China(U1760103)
通过高温激光共聚焦显微镜模拟观察了Fe-0.1C-0.21Si-1.2Mn (质量分数，%)包晶钢在不同冷却速率下的包晶相变过程，然后利用试样表面粗糙度变化反映了包晶转变收缩程度的不同。结果显示，冷却速率超过临界值后包晶转变能够发生快速相变，快速相变引起突然的包晶转变收缩和表面粗糙度变化。随冷却速率的增加包晶钢的包晶转变收缩呈先增加后减小的趋势，在冷却速率为20 ℃/s时表面粗糙度达到最大值，此时的表面粗糙度约是低冷却速率(2.5 ℃/s)时表面粗糙度的2.8倍。当冷却速率足够大后包晶转变收缩又开始减小，这一变化为高拉速下减少包晶钢连铸坯表面纵裂纹的发生提供了新策略。
郭军力 , 文光华 , 符姣姣 , 唐萍 , 侯自兵 , 谷少鹏 . 冷却速率对包晶钢凝固过程中包晶转变收缩的影响[J]. 金属学报, 2019 , 55(10) : 1311 -1318 . DOI: 10.11900/0412.1961.2018.00553
Driven by the demand for the improving mechanical properties of steel products and the cost reduction in alloys, steels falling within the peritectic composition range are designed recently. However, notoriously cast surface defects such as cracks, deep oscillation mark formation and breakouts are found to occur frequently during continuous casting of steels, particularly at high casting speeds. This phenomenon is closely related to the shrinkage of phase transformation caused by the peritectic transformation. In order to understand the effects of cooling rate on the contraction of the peritectic transformation, the initial solidification processes of a peritectic steel (Fe-0.1C-0.21Si-1.2Mn, mass fraction, %) were observed using high-temperature confocal laser scanning microscopy under different cooling rates, and then variations in surface roughness were measured to reflect the degree of peritectic transformation contraction. The results show that the peritectic transformation occurs a massive transformation when the cooling rate exceeds the critical value. The massive transformation results in a sudden peritectic transformation contraction and surface roughness variations, which directly cause the occurrence of surface longitudinal cracks of slabs at high casting speeds. The contraction increases first and then decreases with the cooling rate increasing and the maximum surface roughness at the middle cooling rate (20 ℃/s) is about 2.8 times more extensive than that which occurs at the low cooling rate of 2.5 ℃/s. The phenomenon that the peritectic transformation contraction decreases under the high cooling rate may provide a new strategy to reduce cracks occurring in high speed casting.
| [1] | Saleem S, Vynnycky M, Fredriksson H. The influence of peritectic reaction/transformation on crack susceptibility in the continuous casting of steels [J]. Metall. Mater. Trans., 2017, 48B: 1625 |
| [2] | Ma N B, Lei Z S, Jin X L ,et al. Effect of temperature fluctuation on initial solidification process during peritectic steel continuous casting [J]. Acta Metall. Sin., 2008, 44: 1019 |
| [2] | (马宁博, 雷作胜, 金小礼等. 温度波动对包晶钢连铸初始凝固过程的影响 [J]. 金属学报, 2008, 44: 1019) |
| [3] | 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 |
| [3] | (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) |
| [4] | Gao Z, Zhang X Z, Yao S F. Mechanism of crack formation during continuous casting of peritectic steel slabs [J]. J. Iron Steel Res., 2009, 21(10): 8 |
| [4] | (高 仲, 张兴中, 姚书芳. 包晶钢铸坯裂纹形成机理的实验研究 [J]. 钢铁研究学报, 2009, 21(10): 8) |
| [5] | Ridolfi M R, De Vito A, Ferro L. Effect of alloying elements on thermal contraction and crack susceptibility during in-mold solidification [J]. Metall. Mater. Trans., 2008, 39B: 581 |
| [6] | Emi T, Fredriksson H. High-speed continuous casting of peritectic carbon steels [J]. Mater. Sci. Eng., 2005, A413-414: 2 |
| [7] | Cai K K. Quality Control of Continuous Casting Strand [M]. Beijing: Metallurgical Industry Press, 2010: 163 |
| [7] | (蔡开科. 连铸坯质量控制 [M]. 北京: 冶金工业出版社, 2010: 163) |
| [8] | Mondragón J J R, Trejo M H, de Jesús Castro Román M, et al. Description of the hypo-peritectic steel solidification under continuous cooling and crack susceptibility [J]. ISIJ Int., 2008, 48: 454 |
| [9] | Trejo M H, Lopez E A, Mondragon J J R ,et al. Effect of solidification path and contraction on the cracking susceptibility of carbon peritectic steels [J]. Met. Mater. Int., 2010, 16: 731 |
| [10] | Konishi J, Militzer M, Samarasekera I V, et al. Modeling the formation of longitudinal facial cracks during continuous casting of hypoperitectic steel [J]. Metall. Mater. Trans., 2002, 33B: 413 |
| [11] | Hu Z G, Ma C L, Liu L, et al. Region of peritectic reaction in thin slab casting process of CSP [J]. J. Iron Steel Res., 2006, 18(7): 10 |
| [11] | (胡志刚, 马春林, 刘 浏等. CSP薄板坯连铸包晶反应区域的研究 [J]. 钢铁研究学报, 2006, 18(7): 10) |
| [12] | Yasuda H, Nagira T, Yoshiya M ,et al. Massive transformation from δ phase to γ phase in Fe-C alloys and strain induced in solidifying shell [J]. IOP Conf. Ser.: Mater. Sci. Eng., 2012, 33: 012036 |
| [13] | Shibata H, Arai Y, Suzuki M, et al. Kinetics of peritectic reaction and transformation in Fe-C alloys [J]. Metall. Mater. Trans., 2000, 31B: 981 |
| [14] | Griesser S, Bernhard C, Dippenaar R. Effect of nucleation undercooling on the kinetics and mechanism of the peritectic phase transition in steel [J]. Acta Mater., 2014, 81: 111 |
| [15] | Guo J L, Wen G H, Pu D Z, et al. A novel approach for evaluating the contraction of hypo-peritectic steels during initial solidification by surface roughness [J]. Materials, 2018, 11: 571 |
| [16] | Pu D Z, Wen G H, Fu D C, et al. Study of the effect of carbon on the contraction of hypo-peritectic steels during initial solidification by surface roughness [J]. Metals, 2018, 8: 982 |
| [17] | Becker R. Effects of strain localization on surface roughening during sheet forming [J]. Acta Mater., 1998, 46: 1385 |
| [18] | Fu J X, Li X D, Hwang W S. Study of the coefficient of thermal expansion for steel Q235 [J]. Adv. Mater. Res., 2011, 194-196: 326 |
| [19] | Ueshima Y, Mizoguchi S, Matsumiya T ,et al. Analysis of solute distribution in dendrites of carbon steel with δ/γ transformation during solidification [J]. Metall. Trans., 1986, 17B: 845 |
| [20] | Nishimura T, Morishita K, Nagira T ,et al. Kinetics of the δ/γ interface in the massive-like transformation in Fe-0.3C-0.6Mn-0.3Si alloys [J]. IOP Conf. Ser.: Mater. Sci. Eng., 2015, 84: 012062 |
| [21] | Bhattacharyya S K, Perepezko J H, Massalski T B. Nucleation during continuous cooling—Application to massive transformations [J]. Acta Metall., 1974, 22: 879 |
| [22] | Wolf M M. Mold heat transfer and lubrication control—Two major functions of caster productivity and quality assurance [A]. Process Technology Conference Proceedings [C]. Nashville: Iron and Steel Society, 1995: 99 |
| [23] | Hanao M, Kawamoto M, Yamanaka A. Growth of solidified shell just below the meniscus in continuous casting mold [J]. ISIJ Int., 2009, 49: 365 |
| [24] | Kanazawa T, Hiraki S, Kawamoto M, et al. Behavior of lubrication and heat transfer in mold at high speed continuous casting [J]. Tetsu Hagáne, 1997, 83: 701 |
| [24] | (金沢 敬, 平城 正, 川本 正幸等. 高速連続鋳造時の鋳型内潤滑?伝熱挙動 [J]. 鉄と鋼, 1997, 83: 701) |
| [25] | Cicutti C, Boeri R. Analysis of solute distribution during the solidification of low alloyed steels [J]. Steel Res. Int., 2006, 77: 194 |
| [26] | Edvardsson T, Fredriksson H, Svensson I. A study of the solidification process in low-carbon manganese steels [J]. Met. Sci., 1976, 10: 298 |
| [27] | Mizukami H, Suzuki T, Umeda T, et al. Initial stage of rapid solidification of 18-8 stainless steel [J]. Mater. Sci. Eng., 1993, A173: 361 |
| [28] | Dhindaw B K, Antonsson T, Fredriksson H, et al. Characterization of the peritectic reaction in medium-alloy steel through microsegregation and heat-of-transformation studies [J]. Metall. Mater. Trans., 2004, 35A: 2869 |
/
| 〈 |
|
〉 |
