板坯连铸结晶器内钢凝固过程热行为研究 Ⅰ.数学模型

来源期刊：金属学报2011年第6期

论文作者：蔡兆镇 朱苗勇

文章页码：671 - 677

关键词：板坯连铸； 结晶器； 保护渣； δ/γ相变； 热行为

Key words：slab continuous casting； mold； mold flux； δ/γ transformation； thermal behavior

摘    要：建立了伴随δ/γ相变的钢凝固过程两相区溶质微观偏析模型,以其所确立的钢凝固过程各相分数与温度之间的关系获得钢的高温物性参数,并根据连铸坯在结晶器内凝固收缩量与结晶器内表面的位移关系、保护渣的液/固状态及厚度分布、铸坯表面和铜板热面的温度分布以及气隙的动态变化等建立了描述坯壳-铜板界面热流的数学模型.在此基础上,运用率相关本构模型,采用顺序耦合法建立了描述板坯连铸结晶器内钢凝固过程热行为的二维瞬态热/力耦合有限元分析模型.

Abstract: Thermal behavior of the solidifying shell in continuous casting mold is very important to final steel products.In the present work,one two-dimension transient thermal-mechanical coupling finite element model was developed to simulate the thermal behavior of steel solidifying in slab continuous casting mold by using the sequential coupling method.In this model,in order to get the physical properties of steel at high temperature,a microsegregation model which would give the relationship of phase fractions and temperature for acquiring the physical properties with δ/γ transformation in mushy zone was established.And the heat flux was obtained according to the displacement between the surface of solidifying shell and the hot face of mold as solidification contraction,the liquid/solid structure and distribution of mold flux,the temperature distribution of slab surface and mold hot face, and air gap distribution.In addition,the rate-dependent elastic-viscoplastic constitutive equation was applied to account for the evolution of shell stress in the mold.