| 摘要 |
PROBLEM TO BE SOLVED: To reduce center segregation over the total length of a casting piece, and to restrain the occurrence of molten metal leakage after finishing molten steel supply to a casting mold.SOLUTION: An average casting speed Va up to finishing molten steel supply from before one minute for finishing the molten steel supply to a casing mold is set as 0.96×V≤Va≤0.98×V, and an average casting speed Vb until the final end part of a casting piece passes through a bending completion position from after finishing the molten steel supply to the casting mold is set as 0.91×V≤Vb≤0.94×V, and an average casting speed Vc until the final end part of the casting piece passes through a correction completion position from after passing through the bending completion position is set as 0.87×V≤Vc≤0.89×V. After finishing the molten steel supply to the casing mold, a specific water quantity X2 of a range up to 1[m]-2[m] in the casting direction from the final end part of the casting piece is set to 0.1[l/kg] or less. The casting piece is drafted by setting a draft gradient T of a roll stand in a section of becoming 28-37[m] in a meniscus distance as 0.5-1.2[mm/m].SELECTED DRAWING: Figure 3 |
