| 摘要 |
PURPOSE:To obtain products of high accuracy by precision rolling in a finishing stage for wire rods or round bars by bulging oval parts by the use of round calibers then rolling the oval parts with round calibers for finishing at a small reduction rate of area. CONSTITUTION:In a finishing stage for continuous rolling of wire rods or round bars, the material is rolled with round calibers 1, 2 of a diameter D1 to project the material slightly in a range B where the round surfaces are not formed, whereby oval parts 3 are bulged. Therefore, the diameter d2 of the parts 3 is larger than the diameter d1 intersecting orthogonally therewith. The above- mentioned oval parts 3 are located in a range C where the caliber surfaces are formed and are rolled to <=5% reduction rate of area by round calibers 4, 5 for finishing of a diameter D2. Then, the parts 3 are corrected to a round shape, and since the reduction rate of area is decreased, there is no formation of over- filling of the material, etc. and the products of high accuracy are obtained. |
