连铸坯截面尺寸对流动、凝固及溶质分布的影响

Influence of Billet Size on Its Flow, Solidification and Solute Transport in Continuous Casting Process

采用方坯连铸过程三维紊流、凝固传热及溶质传输的耦合模型 ,在其他模拟条件相同的情况下 ,研究铸坯截面尺寸对连铸过程的影响· 结果表明 ,截面尺寸大者 ,入流速度大 ,更深浸入铸坯内部 ,带动较多钢液随之流动 ,在结晶器上部的紊流程度较高· 对于Fe C二元合金 ,由温度和溶质浓度共同决定了凝固坯壳的分布· 小截面尺寸铸坯 ,溶质在各截面上偏析更为严重· 其凝固坯壳也较薄 ,为防止拉漏 。

A 3D coupled turbulent flow, solidification and solute transport model was set up. The influence of square billet size on continuous casting process was studied using this model, while other casting conditions are the same. The larger section billet has the larger inlet velocity which is prone to immerge deeper into the strand, drive more liquid to follow the mainstream and have the higher degree of turbulence at upside of the mold. For a Fe C binary alloy system, the solidification shell is determined by temperature and solute concentration commonly. The smaller section billet tends to worse macrosegregation and thinner shell thickness. A longer mold was suggested to avoid this tendency.