【摘要】 以某钢厂大方坯(325 mm×280 mm)连铸生产过程中轻压下工艺为研究对象，建立平辊、凸辊、直角坯和倒角坯不同组合模式下的压下模型，通过数值模拟研究铸坯表面等效应变分布和厚度方向上应变传递效率，结合工业试验探明不同轻压下工艺对铸坯芯部质量的改善效果。结果表明：凸辊可优化铸坯表面应变分布，降低铸坯角部应变大小，优化铸坯角部受力，减少裂纹发生；压下应变在厚度方向传递效率倒角铸坯要优于直角铸坯，可从13.3%～14.7%提升至43.2%～50%;凸辊在应变传递效率上优于平辊，直角坯可从13.3%提升至14.7%,倒角坯可从43.2%提升至50%;工业试验结果显示，平辊+倒角坯的组合对芯部质量改善效果显著，且铸坯的倒角方法对于坯料宏观偏析的改善效果，较凸辊压下方法更为突出。更多还原

【Abstract】 This study takes the soft reduction process during continuous casting of large square blooms(325 mm × 280 mm) at a steel plant as the research object. Reduction models were established for different combination modes of flat rolls, convex rolls, right-angle blooms, and chamfered blooms. The distribution of equivalent strain on the bloom surface and the strain transfer efficiency in the thickness direction were investigated through numerical simulation, with the effectiveness verified by industrial trials. The results show that: convex rolls optimize the surface strain distribution of the bloom, reduce corner strain magnitude, improve stress conditions at the corners, and decrease crack occurrence. Chamfered blooms exhibit superior strain transfer efficiency in the thickness direction compared to right-angle blooms, with efficiency increasing from 13.3%～14.7% to 43.2%～50%. Convex rolls outperform flat rolls in strain transfer efficiency, efficiency increases from 13.3% to 14.7% for right-angle blooms and from 43.2% to 50% for chamfered blooms. Industrial trials demonstrate that applying flat rolls to chamfered blooms significantly improves core quality. Furthermore, the chamfering method of the cast billet has a more significant effect on improving the macrosegregation of the billet compared to the convex roller pressing method.更多还原