PURPOSE: To roll a rolling material into a plate having a large step difference without causing turbulence in its flatness by controlling the advancing and returning rollings of the material, in rolling a rolling material by leaving a part of the material by a prescribed length and rolling the other part into a thinner one through several passes of reversing rollings.
CONSTITUTION: A steel plate 1 rolled into the sheet thickness t1 is rolled into the sheet thickness t1' by upper and lower work rolls 2, 3 having a roll gap S1 between them, and when the top of plate 1 is detected by a steel plate detector 4, the rotation of mill is stopped to leave a thick-plate part having thickness t1 by a length l1. Successively a return rolling is performed by reversing the mill to obtain a thin-plate part having sheet thickness t1". Further, the 2nd pass rolling is performed to obtain a thin plate-thickness t2' part by regulating the roll gap to S2(S1>S2), and the mill is reversed when the detector 4 detects the top of plate 1 to obtain a thin plate-thickness t2 part. In this way, a plate with different thicknesses is obtained, which consists of a part having a prescribed length l1 and a sheet thickness t1 and a remaining part having a sheet thickness t2.
OKAMURA ISAMU
OGAWA TAKAO
ORITA ASAYUKI
INOUE MASATOSHI
| JPS4860059A | 1973-08-23 | |||
| JPS5249781A | 1977-04-21 |
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