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对不同浇铸条件下的低碳钢连铸板坯进行了凝固钩(Hook)的特征研究,根据凝固钩的形貌概括了凝固钩的不同类型,统计了凝固钩周围气泡和夹杂物的分布,讨论了不同浇铸参数对铸坯凝固钩深度的影响,并通过Bikerman方程和弯月面凝固理论对凝固钩的不同特征进行了解释.结果表明:按形貌可将凝固钩分为完整叶状、双凝固钩、弯曲截断型和二次凝固型四种类型,其中二次凝固型的凝固钩出现的概率最高为46.8%,而完整叶状、弯曲截断型和二次凝固型的凝固钩出现概率分别为25.3%、7.6%和6.3%;研究发现,凝固钩周围的夹杂物数量明显多于其他区域的夹杂物数量,说明凝固钩能够捕获结晶器内上浮的夹杂物;对比不同浇铸参数发现,采用结晶器电磁制动装置(FC-Mold)、减小结晶器水口浸入深度、增大浇铸拉速均能够减小凝固钩的深度;Bikerman方程的计算结果和弯月面凝固理论能在机理上解释凝固钩的形貌特征.
The characteristics of Hooks were studied under different casting conditions. The different types of coagulation hooks were summarized according to the morphology of coagulation hooks. The distribution of bubbles and inclusions around coagulation hooks was calculated. The influence of different casting parameters on the solidification hook depth of billet was discussed, and the different characteristics of the solidification hook were explained by Bikerman equation and meniscus solidification theory.The results showed that the solidification hooks could be divided into complete leaf shape, Double coagulation hook, curved truncated and secondary coagulation types, of which the second coagulation type coagulation hook appears the highest probability of 46.8%, while the complete leaf, curved truncated and secondary coagulation type coagulation hook appearance probability Which is 25.3%, 7.6% and 6.3% respectively. It is found that the number of inclusions around the coagulation hooks is much more than that of other areas, which indicates that the coagulation hooks can catch the floating inclusions in the mold. Comparing different casting parameters, The use of mold electromagnetic brake device (FC-Mold), to reduce the mold inlet depth, increase casting speed can reduce the depth of the coagulation hook; Bikerman equation results and the theory of meniscus solidification Solidified topography hook explained mechanistically.