| 摘要 |
PURPOSE:To stably produce a cast thin slab having excellent shape characteristic without any crack, etc., by arranging many small dented parts having the specific size and shape on surface of drum for cooling molten metal in continuous casting apparatus. CONSTITUTION:The molten metal in a tundish 1 is flowed into pouring basin 3 between the cooling drums 2, 2 and continuously drawn as the cast thin slab 5 by rotating the cooling drums 2, 2. In this case, many dents 11 having circular or elliptic opening parts with 0.1-1.2mm diameter and 5-100m depth are uniformly arranged without contacting with mutual dents 11 on Ni plating layer 13 on the surface of the cooling roll 2. When the molten metal forms the solidified shell 15 on the surface of the cooling drum 2, these dents 11 form air gaps, which independently exist without mutual continuity. As the high temp. solidified layers having low rigidity, slowly cooled by the air gaps, are surrounded with the part having high rigidity, which are sufficiently cooled by directly contacting with the cooling drums except the dented 11 part, the development of the crack caused by shrinkage of the solidified shell 15 is restrained and the thin cast slab 5 having excellent surface characteristic is obtd. |
