| 摘要 |
PURPOSE:To suppress the generation of surface cracking of steel slabs effectively in the stage of continuous casting of middle carbon steel by regulating the negative time of oscillations to be applied to a water-cooled mold and the viscosity of the mold powder to be charged. CONSTITUTION:In the stage of continuous casting for slabs of middle carbon region steel contg. 0.08-0.16wt% C, the time when a water cooled mold descends at a speed higher than the drawing speed of the slab in one cycle of the oscillations to be applied to said mold, that is, the negative time TN expressed by the equation (n: drawing speed cm/sec, f: oscillating frequency of the mold c/ sec, S: oscillating stroke of the mold cm) is adjusted within 0.21sec. Further the mold powder having 3.5-8.0 poise viscosity at 1,300 deg.C is used for the mold powder to be charged into the mold. By the above-mentioned method, the surface cracking of the slabs of the middle carbon region steel is suppressed effectively, and the loss of yield is reduced. |
