Continuous casting of hypo-peritectic steel was conducted with a pilot slab caster. Such experimental data as local heat flux, thickness of solidified shell or mold flux film, and dendrite primary arm spacing were obtained. On the basis of these experimental results, influence of mold flux on initial solidification in the mold was discussed. With mild cooling by crystallization of mold flux, local heat flux and solidification rate decreased in the mold. The changes in them quantitatively correspond to each other. Dendrite primary arm spacing increased with the mild cooling. Relationship between the arm spacing and cooling rate was established and cooling rate on quite initial stage of solidification was stimated. Cooling rate at 1 mm thickness of solidified shell was estimated as about 10000–17000 K/min and changed by mold flux. Unevenness of the solidified shell thickness becomes remarkable when the shell grows to be 1 mm thick. Relation between the unevenness and the cooling rate was discussed, and critical cooling rate against the uneven solidification was observed around 17000 K/min. Thermal resistance of mold flux film was also evaluated and it was clarified that thermal resistance in the film is larger than that by air gap, and Crystallization in the film contributes to increase of both resistances. It is also considered that increase of casting speed makes air gap thinner, so reduction of radiation by crystallization of mold flux becomes more important in high speed continuous casting.
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机译：用中试板坯连铸机连续浇铸次包晶钢。获得了诸如局部热通量，凝固壳或铸模通量膜的厚度以及枝晶一次臂间距等实验数据。在这些实验结果的基础上，讨论了结晶器通量对结晶器中初始凝固的影响。随着结晶器熔剂结晶的温和冷却，结晶器中的局部热通量和凝固速率降低。它们之间的变化在数量上相互对应。树突状主臂间距随温和冷却而增加。建立了臂间距与冷却速率之间的关系，并在凝固的初期就刺激了冷却速率。凝固壳厚度为1 mm时的冷却速率估计约为10000-17000 K / min，并随铸模通量的变化而变化。当壳长到1mm厚时，凝固壳厚度的不均匀性变得明显。讨论了不均匀度与冷却速率之间的关系，观察到了针对不均匀凝固的临界冷却速率，约为17000 K / min。还评价了保护渣膜的热阻，并且明确了膜中的热阻大于气隙引起的热阻，并且膜中的结晶有助于增加两个电阻。还可以认为，提高铸造速度会使气隙变薄，因此在高速连续铸造中，通过保护渣的结晶化来降低放射线变得更加重要。
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