Prior to the rolling of a flat rolling material (2) on a rolling line that includes a number of roll stands (1), a control system (3) receives actual variables (I) and target variables (Z) of the material (2). The control system (3) determines desired values (S*) for the roll stands (1), based on the actual (I) and target variables (Z) in combination with a model (10) of the rolling line, such that expected variables (E1) of the material (2) after its rolling are aligned as far as possible with the target variables (Z) and transfers the desired values (S*) to the roll stands (1) such that the material (2) is rolled according to the desired values (S*). The target variables (Z) comprise at least one freely selectable, discrete characteristic variable (K1 to K5, K2′ to K4′, K2″ to K4″) defining the contour (K) of the flat rolling material (2).

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 rolling line for rolling a flat rolling material (2) includes a number of roll stands (1). Prior to the rolling, a control system (3) receives actual variables (I) of the material (2) before the rolling and target variables (Z) after the rolling. The control system (3) determines desired control variables (S*) for the roll stands (1), based on the actual (I) and target variables (Z), in combination with a description (B) of the rolling line, using a model (10) of the rolling line. The control system (3) determines the desired values (S*) such that expected variables (E1) for the material (2) after its rolling are aligned as far as possible with the target variables (Z). The control system (3) transfers the desired values (S*) to the roll stands (1) such that the material (2) is rolled according to the transferred desired values (S*). The target variables (Z) comprise at least one freely selectable, discrete characteristic variable (K1 to K5, K2′ to K4′, K2″ to K4″) defining the contour (K) of the flat rolling material (2).

An edging method including changing an incident angle of a slab with respect to a pair of edging members that are disposed on a conveyance line of the slab and that edge the slab based on information relating to the slab acquired at at least one of prior to edging or after edging.

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.

An edging method including changing an incident angle of a slab with respect to a pair of edging members that are disposed on a conveyance line of the slab and that edge the slab based on information relating to the slab acquired at at least one of prior to edging or after edging.