| 摘要 |
PROBLEM TO BE SOLVED: To improve a yield by more surely preventing orange-peeling or surface-roughening.SOLUTION: A method for manufacturing a deformed cross-sectional bar includes a step of rough rolling, a step of annealing, and a step of finish rolling. In the step of rough rolling and the step of finish rolling, a flat sheet stock or a deformed cross-sectional material is put and rolled two or more times between a plurality sets of rolling rolls consisting of: a stepped roll, on which small-diameter roll parts for forming thick-thickness parts and large-diameter roll parts for forming thin-thickness parts are formed being aligned in the axial direction; and a flat roll, whose diameter is made constant along the axial direction. In the step of rough rolling, the reduction rates of the thin-thickness parts are made larger than those of the thick-thickness parts, and then rolling is performed two or more times. In the step of finish rolling, the reduction rates of the thin-thickness parts and of the thick-thickness parts are made equal, and then rolling is performed two or more times. |
