中南大学学报（自然科学版）2018，Vol.49Issue(5)：1037-1046,10.DOI:10.11817/j.issn.1672-7207.2018.05.003
高碳耐磨球钢大方坯连铸过程凝固定律及在轻压下过程中的应用
Solidification regularity of high carbon wear-resistant ball steel in bloom continuous casting and its application in soft reduction process
摘要
Abstract
A two-dimensional mathematical model of solidification and heat transfer for a bloom with the cross section of 310 mm×360 mm(length×width) was established with ANSYS software, which was verified by nail-shooting experiments in the narrow side of the bloom and surface temperature testing. The solidified shell growth law of high carbon wear-resistant ball steel with different carbon mass fractions in both wide and narrow side of the bloom was simulated based on the model. The results were also applied in the soft reduction process and the field experiments were carried out. The results show that the solidified shell thickness distribution of the bloom, the position of the solidification end point and the solid fraction in the core of the solidified strand under different working conditions can be accurately obtained by using this model at any fixed location along the casting direction. In addition, high carbon wear-resistant ball steels with different carbon mass fractions obey the same law of solidification: from the meniscus of the crystallizer to the secondary cooling zone export, the solidified shell thickness in the columnar crystal zone of the bloom and the square root of solidification time show a linear relationship, which fits the square root law.The correction term of the law is relevant to the superheat. However, from the secondary cooling zone export to the end of solidification, the relationship between solidified shell thickness in the equiaxed crystal zone of the bloom and the square root of solidification in the columnar crystal zone is non-linear. In accordance with the calculated solid fraction at the centerline of strand in wear resisting ball steel BU bloom by model of solidification and heat transfer, combined with reasonable soft reduction zone, the casting speed increases from 0.43 m/min to 0.52 m/min. Consequently, soft reduction zone is prolonged and the center carbon segregation on wear resisting ball steel BU is reduced obviously.关键词
大方坯/凝固传热/数学模型/高碳耐磨球钢Key words
bloom/solidification and heat transfer/mathematical models/high carbon wear-resistant ball steel分类
矿业与冶金引用本文复制引用
安航航,包燕平,王敏,赵立华..高碳耐磨球钢大方坯连铸过程凝固定律及在轻压下过程中的应用[J].中南大学学报（自然科学版）,2018,49(5):1037-1046,10.基金项目
国家自然科学基金资助项目(51404018) （51404018）
钢铁冶金新技术国家重点试验室自主基金资助项目(41614014)(Project(51404018)supported by the National Natural Science Foundation of China （41614014）
Project(41614014)supported by the Foundation of State Key Laboratory of Advanced Metallurgy) （41614014）
