| 摘要 |
PROBLEM TO BE SOLVED: To efficiently and economically manufacture a H-section steel having a higher web or a wider flange without using an especially large material cross section or equipment. SOLUTION: In a rough roiling method for the H-section steel which enables the internal dimension of the web to be expanded and rolled by a hole die, an angle of gradient in the internal side surface relation to a vertical line of at least one expanding hole die is shaped smaller than the flange angle of gradient of a material to be rolled before rolling by the hole die, and the web internal dimension is expanded and rolled. Alternatively, after the flange angle of gradient is expanded by the first hole die and the web internal dimension is also expanded, the web internal dimension is expanded and rolled by a hole die having a smaller angle of gradient in the internal side surface than the flange angle of gradient. |
