| 摘要 |
PROBLEM TO BE SOLVED: To provide a cooling drum having dimples with which a thin cast slab having necessary shaped convex projections can be cast, and a long service life, and to provide a twin-drum type thin cast slab continuous casting method by using the cooling drum. SOLUTION: In the twin-drum type continuous casting, with which molten steel is poured into a molten steel pool part formed of a pair of cooling drums having parallel axes and rotated in the mutually reverse direction and the side weirs, and while cooling and solidifying the molten steel on the peripheral surfaces of the cooling drums, the thin cast slab is continuously cast, as the cooling drum for continuously casting the thin cast slab, the cooling drum forming a dimple having 200-2000μm circle-equivalent average diameter and >200 to 1000μm average depth on the peripheral surface at 30-70% area ratio, is used, and also, the molten steel pool part is covered with atmospheric gas composed of Ar and N2 . The mixing ratio of Ar is desirable to be 1-10%.
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