| 摘要 |
PURPOSE:To reduce the original unit of rolls advantageously by considerable decrease in the use of costly caliber rolls by using flat roll passes frequently in reducing of blooms or billets to bar steel, and rolling the bar steel with the caliber roll passes disposed partly. CONSTITUTION:A blank material 8 having a square section is rolled continuously >=2 times with flat rolls 9, 9', 9''. The rolled material 8 is subjected to a process for trimming the sectional shape of the material 8 by a single pass of box type rolls 10 or combined passes of diamond caliber rolls 11 and square caliber rolls 12 repeatedly each time when needed, whereby the section thereof is reduced. In this way, the twists and overturns produced when the material is subjected to continuous passes of 2 times or over with flat rolls are corrected with the caliber roll passes, so that the continuation of the succeeding rolling is made easy. The life of the caliber rolls is remarkably prolonged by the said method and the rolling efficiency for the bar steel is improved considerably. |
