| 摘要 |
PURPOSE:To obtain a prescribed product stepped only one side by overlapping two slabs to intermittently weld the boundary parts of the side faces of them for joining them together after interposing a release agent between them and releasing them from each other by cutting off their surroundings after performing a differential thickness rolling in hot state. CONSTITUTION:A prescribed quantity of a release agent for preventing sticking is coated on the matching surface of two slabs 1, 1' to overlap them, and the boundary parts of their side faces are intermittenly tack welded 2 while leaving unwelded parts 3, and the lapped material 1p is heated to a prescribed temperature to perform a differential thickness rolling of it by rolling mill 4. At that time, an ordinary rolling is performed till the thickness of the material 1p reaches the thickness (h1+h2), and the differential thickness rolling is successively performed till it reaches the thickness (h1'+h2') between the length l1 thereafter, then a lapped material 1'p of slabs having both stepped sides is obtained. Next, the surroundings of the material 1'p is cut off by a shear or a gas cutter to obtain two sheets having each a stepped one side by releasing and separating them from each other. In this way, a prescribed sheet perfectly free from a remaining step without requiring correcting operations and without causing the generation of strain in the stepped part. |
