A large-size H-shaped steel product is produced by performing a rough rolling step including an edging rolling step of rolling and shaping a material to be rolled into a predetermined almost dog-bone shape, and a flat rolling step of performing rolling of a web part by rotating the material to be rolled after completion of the edging rolling step by 90° or 270°, upper and lower caliber rolls of at least one caliber of calibers configured to perform the flat rolling step include recessed parts configured to form a raised part at a middle of a web part of the material to be rolled, the recessed parts being provided at roll barrel length middle parts of the upper and lower caliber rolls.

A large-size H-shaped steel product is efficiently and stably produced by performing flat shaping and rolling of a large-size raw blank while improving a generation efficiency of flanges without bringing about problems such as elongation in a web height direction and deformation of a flange corresponding part. A rough rolling step includes an edging rolling step of rolling and shaping a material to be rolled into a predetermined almost dog-bone shape, and a flat rolling step of performing rolling of a web part by rotating the material to be rolled after completion of the edging rolling step by 90 or 270, upper and lower caliber rolls of at least one caliber of calibers configured to perform the flat rolling step include recessed parts configured to form a raised part at a middle of a web part of the material to be rolled, the recessed parts being provided at roll barrel length middle parts of the upper and lower caliber rolls, a width of the raised part formed in the flat rolling step is set to 25% or more and 50% or less of a web part inner size of the material to be rolled, and a thickness of the web part rolled in the flat rolling step is set to a predetermined thickness thicker than a web part thickness when the intermediate rolling step is started.

[Object] To produce an H-shaped steel product with a flange width larger than a conventional flange width by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending flange portions formed by the splits. [Solution] Provided is a method for producing H-shaped steel using a slab as a material. In a rolling mill that performs a rough rolling step, a plurality of calibers to shape a material to be rolled, and a web thinning caliber to thin a web of the material to be rolled that has been shaped in the plurality of calibers are engraved, the number of the plurality of calibers being three or more. Shaping of a plurality of passes is performed on the material to be rolled in part or all of the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed. The projections formed in the first caliber and the second caliber have a tip angle of 40 or less.

[Object] To produce an H-shaped steel product with a flange width larger than a conventional flange width by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending flange portions formed by the splits.

[Solution] Provided is a method for producing H-shaped steel using a slab as a material. In a rolling mill that performs a rough rolling step, a plurality of calibers to shape a material to be rolled, and a web thinning caliber to thin a web of the material to be rolled that has been shaped in the plurality of calibers are engraved, the number of the plurality of calibers being three or more. Shaping of a plurality of passes is performed on the material to be rolled in part or all of the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed. The projections formed in the first caliber and the second caliber have a tip angle of 40 or less.

A cold rolling method includes: a calculation step of calculating a leveling amount of a rolling mill using an out-of-plane deformation amount of a steel sheet measured on an upstream side of the rolling mill; a control step of controlling leveling of the rolling mill on a basis of the leveling amount calculated in the calculation step; and a cold rolling step of applying cold rolling to the steel sheet using the rolling mill controlled by the control step.