Abstract Based on the mechanisms of macrosegregation evolution in large steel ingots, an approach named as gradual-cooling solidification (GCS) was proposed to alleviate the macrosegregation of large steel ingots. A three-phase mixed columnar dendritic-equiaxed solidification model was employed to investigate the approach. The solidification model considered the dendritic structure of equiaxed grains, nucleation and growth of equiaxed crystals, growth of columnar trunks, thermal-solutal buoyancy, sedimentation of equiaxed crystals, and columnar-to-equiaxed transition (CET). After the verification of model accuracy by a reported experiment results of a 55-ton steel ingot, this model has been used to study the GCS approach. The simulation results showed that the GCS approach has significant potential to alleviate the macrosegregation of the large steel ingot; e.g., for a 55-ton steel ingot, the variation range of segregation value decreased from 0.854 in the conventional casting case to 0.077 in the GCS case.

中文翻译：

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缓冷凝固方法缓解大钢锭宏观偏析

摘要 基于大钢锭宏观偏析演化机理，提出了缓冷凝固(GCS)方法来缓解大钢锭宏观偏析。采用三相混合柱状枝晶-等轴凝固模型来研究该方法。凝固模型考虑了等轴晶粒的树枝状结构、等轴晶体的成核和生长、柱状主干的生长、热溶质浮力、等轴晶体的沉降和柱状到等轴转变（CET）。通过对55吨钢锭的报告实验结果验证模型精度后，该模型已用于研究GCS方法。模拟结果表明，GCS方法在缓解大钢锭宏观偏析方面具有显着潜力；例如，对于 55 吨钢锭，偏析值的变化范围从常规铸造情况下的 0.854 下降到 GCS 情况下的 0.077。