Rolled H-shaped steel is characterized in that a top 5% average value of Mn concentrations in a most embrittled portion in a flange is 1.6 times or less an Mn concentration at a position of 1/6 in a flange width direction from an end face in the flange width direction and 1/4 in a flange thickness direction from a face of a flange positioned on a side opposite to that of a web, and a top 5% average value of Mn concentrations in a central segregation portion dispersed in a region 15 mm or more apart from a center of the flange width toward one end face or both end faces in the flange width direction and within 2 mm from a flange surface layer in the thickness direction is not less than 1.1 times nor more than 1.6 times the Mn concentration at the position of 1/6 in the flange width direction from the end face in the flange width direction and 1/4 in the flange thickness direction from the face of the flange positioned on the side opposite to that of the web.

[Object] To enable an improvement in material-passing property and an improvement in dimensional accuracy in the following manner: when splits are created on end surfaces of a material (e.g., slab) by using projections with acute-angle tip shapes, and flange portions formed by the splits are sequentially bent in a plurality of calibers, a wedge-portion height of each caliber is set to a height satisfying a predetermined condition.

[Solution] Provided is a method for producing H-shaped steel, the method including: a rough rolling step; an intermediate rolling step; and a finish rolling step. A slab material whose slab width/slab thickness is equal to or more than 6.0 and equal to or less than 7.7 is used as a material to be rolled. In a rolling mill that performs the rough rolling step, a plurality of calibers to shape the material to be rolled are engraved, the number of the plurality of calibers being four or more. Shaping of one or a plurality of passes is performed on the material to be rolled in 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. The projections formed in the first caliber are designed to have a height of 100 mm or more, and the projections formed in the first caliber and the second caliber have a tip angle of equal to or more than 25 and equal to or less than 40.

[Object] To enable an improvement in material-passing property and an improvement in dimensional accuracy in the following manner: when splits are created on end surfaces of a material (e.g., slab) by using projections with acute-angle tip shapes, and flange portions formed by the splits are sequentially bent in a plurality of calibers, a wedge-portion height of each caliber is set to a height satisfying a predetermined condition.

[Solution] Provided is a method for producing H-shaped steel, the method including: a rough rolling step; an intermediate rolling step; and a finish rolling step. A slab material whose slab width/slab thickness is equal to or more than 6.0 and equal to or less than 7.7 is used as a material to be rolled. In a rolling mill that performs the rough rolling step, a plurality of calibers to shape the material to be rolled are engraved, the number of the plurality of calibers being four or more. Shaping of one or a plurality of passes is performed on the material to be rolled in 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. The projections formed in the first caliber are designed to have a height of 100 mm or more, and the projections formed in the first caliber and the second caliber have a tip angle of equal to or more than 25 and equal to or less than 40.

To efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width and prevent a shape defect from occurring in shaping using a flat shaping caliber at a rough rolling step. A rolling mill that performs the rough rolling step is engraved with a plurality of calibers configured to shape a material to be rolled, the number of the plurality of calibers being five or more; shaping in one or a plurality of passes is performed on the material to be rolled in the plurality of calibers; a first caliber and a second caliber of the plurality of calibers are formed with projections configured to create splits vertically with respect to a width direction of the material to be rolled; in the second caliber and subsequent calibers of the plurality of calibers, reduction is performed in a state where end surfaces of the material to be rolled are in contact with peripheral surfaces of the calibers in shaping in at least one pass or more; in a third caliber and subsequent calibers excluding a final caliber of the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed; and the final caliber of the plurality of calibers is a flat shaping caliber, and rolling and shaping in the flat shaping caliber is performed under a rolling condition that a pulldown rate is 1.0 or less.

To efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width by creating deep splits on end surfaces of a material such as a slab using projections in acute-angle tip shapes and sequentially bending flange portions formed by the splits to thereby suppress occurrence of shape defects in a material to be rolled and reduce growth of a crop portion. A first caliber and a second caliber of a plurality of calibers are formed with projections configured to create splits vertically with respect to a width direction of the material to be rolled to form divided parts at end portions of the material to be rolled; a third caliber and subsequent calibers excluding a final caliber of the plurality of calibers are formed with projections configured to come into contact with the splits to sequentially bend the divided parts formed; and in at least one pass or more of rolling and shaping in the plurality of calibers, the rolling and shaping is performed with a rolling roll gap for a predetermined section at a rear end portion in a rolling longitudinal direction of the material to be rolled expanded as compared with a rolling roll gap for other than the predetermined section.

To efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width by creating deep splits on end surfaces of a material such as a slab using projections in acute-angle tip shapes and sequentially bending flange portions formed by the splits to thereby suppress occurrence of shape defects in a material to be rolled and reduce growth of a crop portion. A first caliber and a second caliber of a plurality of calibers are formed with projections configured to create splits vertically with respect to a width direction of the material to be rolled to form divided parts at end portions of the material to be rolled; a third caliber and subsequent calibers excluding a final caliber of the plurality of calibers are formed with projections configured to come into contact with the splits to sequentially bend the divided parts formed; and in at least one pass or more of rolling and shaping in the plurality of calibers, the rolling and shaping is performed with a rolling roll gap for a predetermined section at a rear end portion in a rolling longitudinal direction of the material to be rolled expanded as compared with a rolling roll gap for other than the predetermined section.

To efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width, and separately shape by the same roll H-shaped steels different in flange width in the H-shaped steel product with a large flange width. A rolling mill that performs a rough rolling step is engraved with a plurality of calibers configured to shape a material to be rolled, the number of the plurality of calibers being seven or more; the plurality of calibers include a plurality of wedging calibers as calibers at a previous stage provided with projections configured to create splits vertically with respect to a width direction of the material to be rolled, and a plurality of bending calibers as calibers at a subsequent stage configured to bend flange corresponding portions of the material to be rolled formed by the wedging calibers; the wedging calibers include calibers configured to create two kinds of splits different in length; the bending calibers include calibers having dimensions according to two kinds of flange corresponding portions different in length formed in the material to be rolled in the wedging calibers; and in the bending calibers, reduction is performed in a state where end surfaces of the material to be rolled are in contact with peripheral surfaces of the calibers in shaping in at least one pass or more.

To efficiently and stably produce an H-shaped steel product with a flange width larger than a conventional flange width, and separately shape by the same roll H-shaped steels different in flange width in the H-shaped steel product with a large flange width. A rolling mill that performs a rough rolling step is engraved with a plurality of calibers configured to shape a material to be rolled, the number of the plurality of calibers being seven or more; the plurality of calibers include a plurality of wedging calibers as calibers at a previous stage provided with projections configured to create splits vertically with respect to a width direction of the material to be rolled, and a plurality of bending calibers as calibers at a subsequent stage configured to bend flange corresponding portions of the material to be rolled formed by the wedging calibers; the wedging calibers include calibers configured to create two kinds of splits different in length; the bending calibers include calibers having dimensions according to two kinds of flange corresponding portions different in length formed in the material to be rolled in the wedging calibers; and in the bending calibers, reduction is performed in a state where end surfaces of the material to be rolled are in contact with peripheral surfaces of the calibers in shaping in at least one pass or more.

An H-section steel has a predetermined chemical composition in which Ti oxides having a grain size of 0.01 m to 3.0 m are included at a density of 30 pieces/mm.sup.2 or more, a thickness of a flange is 100 mm to 150 mm, an area fraction of bainite at a position from a surface of the flange in a length direction and at a position from the surface thereof in a thickness direction is 80% or more, a yield strength or 0.2% proof stress is 450 MPa or more, and a tensile strength is 550 MPa or more, a Charpy absorbed energy at 21 C. at a position from the surface of the flange in the length direction and at a position from the surface thereof in the thickness direction is 100 J or more, and an average austenite grain size is 50 m to 200 m.

An H-section steel has a predetermined chemical composition in which Ti oxides having a grain size of 0.01 m to 3.0 m are included at a density of 30 pieces/mm.sup.2 or more, a thickness of a flange is 100 mm to 150 mm, an area fraction of bainite at a position from a surface of the flange in a length direction and at a position from the surface thereof in a thickness direction is 80% or more, a yield strength or 0.2% proof stress is 450 MPa or more, and a tensile strength is 550 MPa or more, a Charpy absorbed energy at 21 C. at a position from the surface of the flange in the length direction and at a position from the surface thereof in the thickness direction is 100 J or more, and an average austenite grain size is 50 m to 200 m.