Production method for hat-shaped steel sheet pile

A production method for a hat-shaped steel sheet pile, comprising:

• performing rough rolling on a material to be rolled through hot rolling,
• performing intermediate rolling on the material to be rolled through hot rolling,
• performing finish rolling on the material to be rolled through hot rolling, and
• after performing the rough rolling, the intermediate rolling, and the finish rolling, then performing bending forming,
• wherein the material to be rolled is composed of a web corresponding part, flange corresponding parts, arm corresponding parts, and joint corresponding parts;
• wherein 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;
• wherein 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;
• and
• wherein 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.