| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cast slab having low degree of segregation in low temp. casting under stable conditions without needing an excess heating mechanism or addition of a coolant by utilizing the remaining heat in a tundish heated up at the last time. SOLUTION: When molten low alloy steel containing 0.9-1.3% C and 1.0-6.0% Cr is continuously cast at 10-25 deg.C over-heat degree, the tundish heated up when a kind of steel having the casting temp. higher than that of the temp. of the molten low alloy steel is continuously cast is used as the high temp. state, and the molten low alloy steel is continuously cast at a low casting flow rate of 1.3-1.5 ton/min average flow rate. The continuous casting of the molten low alloy steel is desirably started before reaching the empty furnace time limit (min) of the tundish defined by the equationγ=50.5×β×(T0-T1)0.1/T0, wherein T0 is the casting temp.( deg.C) of the kind of steel prior to the continuous casting of the molten low alloy steel, T1 is the casting temp.( deg.C) of the molten low alloy steel andβis the casting time (min) of the kind of steel prior to the continuous casting of the molten low alloy steel and, in the case of casting time exceeding 200 min,βis fixed to 200.
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