Slab casting method

A slab casting method using a twin-drum continuous casting device that manufactures a slab by solidifying molten metal by a pair of rotating casting drums, the method comprising:

• calculating estimated sheet thicknesses on both ends in a width direction of the slab from equation 1:
• (Estimated sheet thickness)=(cylinder screw down position)+(elastic deformation of casting drum)+(casting drum housing screw down system deformation)+(drum profile of casting drum)−(elastic deformation of casting drum at a time of screw down position zero adjustment) equation 1
• wherein the casting drum housing screw down system deformation indicates a deformation characteristic of housings that support the casting drums and a deformation characteristic of a screw down system that screws down the casting drums obtained before casting of the slab starts;
• and
• controlling screw down positions of cylinders provided on both ends in a width direction of the casting drums so that a difference in estimated sheet thickness between both the ends becomes a predetermined value or smaller,
• wherein, in the equation 1, the cylinder screw down position and the casting drum housing screw down system deformation indicate a difference from an initial value at the time of screw down position zero adjustment, respectively, and
• wherein the casting drum housing screw down system deformation is obtained on the basis of the cylinder screw down positions and a load obtained by tightening in a state of:
• opening a pair of side weirs provided on ends in the width direction of the casting drums;
• and
• interposing a sheet with a uniform sheet thickness longer in sheet width than a drum length of the casting drums between the casting drums.