Abstract: A method of enlarging width of a cast piece during continuous casting. It comprises stopping pouring a molten steel into a mold during continuous casting, positioning a supporting plate at the bottom of the mold without lowering the surface of the bath, moving a short wall of the mold, placing a cooling agent on the supporting plate inside the mold, pouring the molten steel into the mold to obtain a cast piece, and thereafter removing the supportng plate to withdraw the cast piece. An apparatus for placing the supporting plate such that it can move back and fore freely on the bottom of the moving short wall of the mold is provided. In order to smooth the movement of the short wall of the mold, a lubricating agent may be placed at a portion where the long walls contact the short wall of the mold, or holes or grooves for supplying lubricating agent may be provided on both ends of the short wall of the mold.

Abstract: A method of enlarging width of a cast piece during continuous casting. It comprises stopping pouring a molten steel into a mold during continuous casting, positioning a supporting plate at the bottom of the mold without lowering the surface of the bath, moving a short wall of the mold, placing a cooling agent on the supporting plate inside the mold, pouring the molten steel into the mold to obtain a cast piece, and thereafter removing the supporting plate to withdraw the cast piece. An apparatus for placing the supporting plate such that it can move back and fore freely on the bottom of the moving short wall of the mold is provided. In order to smooth the movement of the short wall of the mold, a lubricating agent may be placed at a portion where the long walls contact short wall of the mold, or holes or grooves for supplying lubricating agent may be provided on both ends of the short wall of the mold.