| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method of steel which reliably prevents transversal cracking of a cast metal.SOLUTION: Molten steel 11 is poured into a casting mold 5 of a vertical bend type continuous casting machine 1. The casting mold 5 is cooled while being vibrated in the casting direction. A solidified shell 13 with a thickness of 9 to 20 mm is formed. The vibrations has an amplitude of 6 mm or less and a frequency of 100 [times/min] or more. Until a cast metal 12 comes into contact with the first roll 6, water is sprayed to the cast metal 12 on condition that specific water quantity H expressed by the relation (1) becomes less than 0.4[l/kg-cast metal]. Surface temperature of the cast metal 12 is set as Ar3 point [°C] or less, subsequently, the cast metal is reheated and, thereby, the surface temperature of the cast metal 12 becomes Ar3 point [°C] or more. H=Q/(W×T×Vc×ρ)...(1), where Q is water quantity [l/min] sprayed onto the surface of the cast metal formed from a length side of the casting mold 5, W is cast metal width [m], T is cast metal thickness [m], Vc is cast metal pulling out speed [m/min] and ρ is density [kg/m] of the cast metal.SELECTED DRAWING: Figure 1 |
