65Mn方坯典型质量缺陷控制工艺研究

Study on the typical quality defect control process of 65Mn billet

针对某钢厂200 mm×200 mm的65Mn铸坯存在脱方、角部凹陷和三角区裂纹等质量问题,通过分析缺陷是由结晶器及二次冷却不均造成的,提出扩大结晶器铜管R角、锥度及增加二冷水量工艺优化方案,扩大结晶器铜管R角及锥度改善结晶器冷却传热,增加二冷水量提高足辊水压,使得二冷段喷淋冷却效果更好,提高铸坯冷却均匀性,铸坯脱方、角部凹陷和三角区裂纹等缺陷明显改善,铸坯质量得到大幅提高。

There is off-square, angle concaves and corner cracks in 200 mm square billet of 65Mn in a certain steel plant, which are caused by the uneven cooling of mold and secondary cooling zone by analyzing. The process optimiza- tion schemes of enlarging the R Angle and the taper and increasing the secondary cooling water flow have been carried out. The method of enlarging the R Angle and the taper of the mold improve the heat transfer of the mold cooling. The in- crease of the secondary cooling water and the water pressure of the foot roller improve the cooling effect of the second- ary cooling section. The cooling uniformity of casting billet has been increased. The test shows the quality problems of off-square, angle concaves and corner cracks have been controlled effectively and the quality of casting billet has been greatly improved.