高碳钢小方坯凝固过程中的等轴晶率预测研究及应用

炼钢 ›› 2026, Vol. 42 ›› Issue (5): 60-67.

高碳钢小方坯凝固过程中的等轴晶率预测研究及应用

包丽明¹,吕国成¹,朱金禄²

1.吉林电子信息职业技术学院,吉林吉林 132021;2.通化钢铁股份公司技术中心,吉林通化 134003

出版日期:2026-09-28 发布日期:2026-09-28

Research on prediction and application of equiaxed grain ratio in the solidification process of high carbon steel billets

BAO Liming¹, LYU Guocheng¹, ZHU Jinlu²

1.Jilin Technology College of Electronic Information, Jilin 132021, China;2.Technology Center of Tonghua Iron and Steel Co., Ltd., Tonghua 134003, China

Online:2026-09-28 Published:2026-09-28

摘要/Abstract

摘要： 为精准调控小方坯连铸凝固组织,提升铸坯质量,建立了柱状晶-等轴晶转变CET(Columnar-to-Equiaxed Transition)预测模型,以SWRH82B钢种为基准,确定过热度27 ℃、拉速1.6 m/min条件下的柱状晶→等轴晶CET转变判据常数(柱状晶向等轴晶转变临界参数)为8.93 ℃·s^1/2·mm^-3/2。通过测量SWRH77B钢二次枝晶间距计算冷却速率,并与模型模拟值对比,验证了数学模型的可靠性(误差较小且变化规律一致)。进一步研究过热度、比水量、拉速三个关键工艺参数对等轴晶率的影响规律,结果表明:过热度每升高10 ℃,等轴晶比率下降1~2百分点;比水量每增加0.2 L/kg,等轴晶比率下降约2百分点;拉速每提高0.2 m/min,等轴晶比率下降1~2百分点。研究结果为小方坯连铸工艺优化、改善凝固组织提供了理论依据与实践指导。

关键词: 方坯连铸;CET;凝固组织;等轴晶率

Abstract: To precisely regulate the solidification structure of continuous casting small billets and improve billet quality, a Columnar-to-Equiaxed Transition (CET) prediction model was established. Taking SWRH82B steel as the reference material, the CET criterion constant for columnar-to-equiaxed transition was determined to be 8.93 ℃·s^1/2·mm^-3/2 under the conditions of a superheat of 27 ℃ and a casting speed of 1.6 m/min. The cooling rate was calculated by measuring the secondary dendrite arm spacing of SWRH77B steel, and the calculated values were compared with the simulated results of the model. The reliability of the mathematical model was verified, with minor errors and consistent variation trends observed. The influence laws of three key process parameters, including superheat, specific water flow rate and casting speed, on the equiaxed grain ratio were further investigated. The results indicated that the equiaxed grain ratio decreased by 1~2 percentage points with every 10 ℃ increase in superheat, decreased by approximately 2 percentage points with every 0.2 L/kg increase in specific water flow rate, and decreased by 1~2 percentage points with every 0.2 m/min rise in casting speed. The research findings provided a theoretical basis and practical guidance for the process optimization of continuous casting small billets and improvement of solidification structure.

Key words: billet continuous casting; columnar-to-equiaxed transition; solidification structure; equiaxed grain ratio

. 高碳钢小方坯凝固过程中的等轴晶率预测研究及应用[J]. 炼钢, 2026, 42(5): 60-67.