PURPOSE: To reduce a material to be rolled stably by employing flat passes for other pass stages except shaping pass times among reduction rolling passes for square steel and round steel, limiting the aspect ratios after rolling of such passes particularly and rotating the material 90° after the respective rolling.
CONSTITUTION: A blank material 1 having a square section is passed through rolling mill stands F1WFn-2 consisting of horizontal rolling mills having flat rolls, whereby the material is reduced alternately. Thereafter, the material 1 is passed through rolling mill stands Fn-1, Fn consisting of horizontal rolling mills having caliber rolls, whereby the material is rolled. During this time, it is necesary to gnaw the material 1 which is rolled with flat rolls to have 3.0 aspect ratop on the flat roll pair of the next stage by rotating the same 90° with a twister 8. The device 8 is constituted of twist clava 9, twisters 10, and guide rollers 11. After the material is twisted to a certain extent with the clava 9, the material is rotated to 90° with the twisters 10.
AOYAMA KAZUO
YANAGISAWA TADAAKI
| JPS5057943A | 1975-05-20 | |||
| JP38015473A | ||||
| JPS5129902U | 1976-03-04 |