To suppress the shape defect at a bite end part of a material to be rolled at a bending rolling stage of a rough rolling step to achieve improvements in productivity such as an improvement in yields and a decrease in crop in production of a steel sheet pile. A production method for producing a steel sheet pile by reducing a raw material in a rectangular cross-section, includes a rough rolling step, an intermediate rolling step, and a finish rolling step, wherein a rolling mill configured to perform the rough rolling step is provided with a caliber configured to perform bending rolling of extending a thickness center line length of the raw material and rolling and shaping the raw material from a rectangular cross-sectional shape to a substantially steel sheet pile cross-sectional shape, and wherein in the bending rolling, rolling that a reduction amount with respect to a predetermined section of a bite end part of the raw material is smaller than a reduction amount with respect to a part other than the predetermined section is performed.

To suppress the shape defect at a bite end part of a material to be rolled at a bending rolling stage of a rough rolling step to achieve improvements in productivity such as an improvement in yields and a decrease in crop in production of a steel sheet pile. A production method for producing a steel sheet pile by reducing a raw material in a rectangular cross-section, includes a rough rolling step, an intermediate rolling step, and a finish rolling step, wherein a rolling mill configured to perform the rough rolling step is provided with a caliber configured to perform bending rolling of extending a thickness center line length of the raw material and rolling and shaping the raw material from a rectangular cross-sectional shape to a substantially steel sheet pile cross-sectional shape, and wherein in the bending rolling, rolling that a reduction amount with respect to a predetermined section of a bite end part of the raw material is smaller than a reduction amount with respect to a part other than the predetermined section is performed.

There is provided a production method for a hat-shaped steel sheet pile including performing rough rolling, intermediate rolling, and finish rolling on a material to be rolled through hot rolling, and then performing bending forming, in which the material to be rolled is composed of a web corresponding part, flange corresponding parts, arm corresponding parts, and joint corresponding parts, corner parts as worked parts are formed at connection places between the web corresponding part and the flange corresponding parts and connection places between the flange corresponding parts and the arm corresponding parts, the intermediate rolling is carried out by performing rolling in a plurality of passes on the material to be rolled in a hot state by using a caliber provided to upper and lower caliber rolls in one or a plurality of intermediate rolling mills in which one stand is configured by one caliber, at a height lower than a predetermined target product height, the bending forming is performed in a hot state and performed in a state where the worked parts have a temperature of transformation point or higher, and in the bending forming, the material to be rolled is formed to have predetermined target height and target width.

There is provided a production method for a hat-shaped steel sheet pile including performing rough rolling, intermediate rolling, and finish rolling on a material to be rolled through hot rolling, and then performing bending forming, in which the material to be rolled is composed of a web corresponding part, flange corresponding parts, arm corresponding parts, and joint corresponding parts, corner parts as worked parts are formed at connection places between the web corresponding part and the flange corresponding parts and connection places between the flange corresponding parts and the arm corresponding parts, the intermediate rolling is carried out by performing rolling in a plurality of passes on the material to be rolled in a hot state by using a caliber provided to upper and lower caliber rolls in one or a plurality of intermediate rolling mills in which one stand is configured by one caliber, at a height lower than a predetermined target product height, the bending forming is performed in a hot state and performed in a state where the worked parts have a temperature of transformation point or higher, and in the bending forming, the material to be rolled is formed to have predetermined target height and target width.

A method for rolling a Z-section sheet pile comprises rolling a curved preform of a web (16) in successive roll gaps defined by at least one roll pair comprising a grooved upper roll (26) and a grooved lower roll (28), wherein: a first corner (18) and an adjoining first part of the curved preform of the web (16) are formed in a first groove (42) of an upper roll (26); and a second corner (20) and an adjoining second part of the curved preform of the web (16) are formed in a first groove (46) of a lower roll (28). In the last roll gaps forming the curved preform of the web (16), the diameter of the lower roll (28) decreases in a discontinuous manner in the interval between the first groove (42) in the upper roll (26) and the first groove (46) in the lower roll (26), and the diameter of the upper roll (26) increases in this interval in a complementary manner.

A method for rolling a Z-section sheet pile comprises rolling a curved preform of a web (16) in successive roll gaps defined by at least one roll pair comprising a grooved upper roll (26) and a grooved lower roll (28), wherein: a first corner (18) and an adjoining first part of the curved preform of the web (16) are formed in a first groove (42) of an upper roll (26); and a second corner (20) and an adjoining second part of the curved preform of the web (16) are formed in a first groove (46) of a lower roll (28). In the last roll gaps forming the curved preform of the web (16), the diameter of the lower roll (28) decreases in a discontinuous manner in the interval between the first groove (42) in the upper roll (26) and the first groove (46) in the lower roll (26), and the diameter of the upper roll (26) increases in this interval in a complementary manner.

A facility cost and a remodeling cost can be reduced, and further, a steel sheet pile product with high dimensional accuracy is produced by suppressing occurrence of warpage of a material to be rolled during bending. There is provided a bending device which produces a steel sheet pile by performing bending on a material to be rolled after being subjected to rough rolling, intermediate rolling, and finish rolling in a hot state, in a direction of increasing a cross sectional height of the material to be rolled, the bending device including: a forming stand including a forming caliber configured by an upper caliber roll and a lower caliber roll; and a drive unit driving either the upper caliber roll or the lower caliber roll.

A facility cost and a remodeling cost can be reduced, and further, a steel sheet pile product with high dimensional accuracy is produced by suppressing occurrence of warpage of a material to be rolled during bending. There is provided a bending device which produces a steel sheet pile by performing bending on a material to be rolled after being subjected to rough rolling, intermediate rolling, and finish rolling in a hot state, in a direction of increasing a cross sectional height of the material to be rolled, the bending device including: a forming stand including a forming caliber configured by an upper caliber roll and a lower caliber roll; and a drive unit driving either the upper caliber roll or the lower caliber roll.