| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of shapes for obtaining a desired amount of enlargement of web height while resducing or evading the generation of recessed shapes on the outside of flanges. SOLUTION: In the manufacturing method of the shapes by hot rolling the shapes using a web-height changing mill with which the web height of a material to be rolled is changed by adjusting the roll width, by this manufacturing method of the shapes, rolling is performed by controlling the change amountΔHi of roll width at each web-height changing pass within the range where the under inequality is satisfied to the changing efficiency Ri which is defined by the ratioΔhi/ΔHi of the change amountΔhi of web-height to be attained to the change amountΔHi of roll width at each web-height expanding pass and the rolling draftΔt2 of cumulative thickness of flanges on and after the web-height changing pass.ΣΔHi(1-Ri)<=2.Δt2. (Σis the total sum about the subscrip i.). |
