| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a deformed wire and steel bar which is extremely high in dimensional accuracy and excellent in the out-of- roundness of the outside diameter by satisfying the fullness into the nodal grooves of a roll and simultaneously preventing excessive over-filling of longitudinal ribs. SOLUTION: Four-roll mills P1, P2 are arranged at the final two passes of a continuous finish rolling line Ls for wires and steel bars. By controlling the interstand tension between the upstream-side four-roll mill and the rolling mill Lsn just before the same in the range of 0.2-1.2 kgf/mm2, the nodes and over-filled longitudinal ribs in four places of the circumference are formed on the surface of a material to be rolled while controlling the fullness of a material into the caliber of the upstream-side four-roll mill P1 and excess and deficiency of over-filled dimensions of the ribs. By shaping by reducing the longitudinal ribs with the downstream-side four-roll mill P2, the out-of-roundness of the outside diameter is secured.
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