【摘要】 针对特大截面圆坯连续浇铸的特点,基于依靠浸入式水口自身结构减小钢流冲击深度,同时保证流动与传热沿周向分布均匀的思想,首次提出了新型浸入式伞形水口设计方案,并建立了结晶器内钢水的流-热-固耦合模型,对钢水的流动、传热和凝固行为进行了数值耦合模拟分析,验证了此水口的优越性与合理性:伞形水口的射流在结晶器内形成上下两个回流区,不仅有利于夹杂物、气体等的上浮分离,还能有效降低钢流冲击深度,使过热钢液均匀分布在结晶器上部,可提高弯月面温度和化渣效果;沿周向凝壳生长均匀,减轻了纵裂纹的萌生概率;在0.35m/min拉速下,出结晶器凝壳厚度达到31.2mm,满足安全生产要求。更多还原

【Abstract】 For the characteristic of continuous casting super-large round bloom,a novel SEN(submerged entry nozzle)called umbrella type SEN was proposed to reduce the impingement depth of molten steel by its own structure and keep fluid flow and heat transfer distributed uniformly in circumferential direction.A coupled analysis mathematical model in continuous casting mold was presented,and the fluid flow,heat transfer and solidification of the molten steel in the mold were simulated.The superiority and rationality of the SEN were verified that the molten steel stream spouted from umbrella nozzle took the shape of upper and lower circulation loops,which can not only be convenient for inclusions and gas to float up,but also can decrease the penetration depth of the jet.Meanwhile,liquid steel with superheat was distributed uniformly at upper mold zone,and a noticeable increase of temperature was observed on meniscus which may benefit the melting of slag;solidified shell distributed uniformly in circumferential direction,thereby reducing the probability of longitudinal crack.Solidified shell was 31.2mm thick at the outlet of the mold at the casting speed of 0.35m/min,which can ensure the safety in production.更多还原