| 摘要 |
PROBLEM TO BE SOLVED: To satisfy a relationship of (the dimension of the radius of curvature of a corner/the dimension d between opposite sides) <=0.2 easily and at low cost by improving the dimensional accuracy of a wire and bar having approximately square-shaped cross section which are obtained by rolling without forming a caliber corresponding to the radius of curvature of the corner on the roll surface. SOLUTION: This method is method for rolling the wire and bar having an approximately circular cross section into an approximately square shape with a 4-roll mill 3 provide with two pairs of rolls 3a, 3a, 3b, 3b. In the case that the diameter of the wire and bar (base material) 1 having the approximately circular cross section before rolling with the 4-roll mill 3 is expressed by d0 and the dimension between the opposite sides of the wire and bar 1 having the approximately square-shaped cross section after rolling by d, rolling is performed taking the draft r which is expressed by r=(d0-d)/d0 within a range of 0.1-0.293.
|
