ArcelorMittal S.A.
Method for manufacturing cold-rolled, welded steel sheets, and sheets thus produced

Abstract:

A method for the manufacture of a cold-rolled steel sheet of thickness e.sub.f between 0.5 mm and 3 mm is provided. At least two hot-rolled sheets of thickness e.sub.i are supplied and butt welded, so as to create a welded joint (S1) with a direction perpendicular to the direction of hot rolling. The at least two hot-rolled sheets are pickled by continuous passage through a bath, then the assembly is cold rolled, in a step (L1), to an intermediate thickness e.sub.int, the direction of cold rolling (DL.sub.1) coinciding with the direction of hot rolling. The cold rolling is carried out with a reduction ratio .function. ##EQU00001## such that: .times..ltoreq..times..times..times..times..times..times..times..times..l- toreq..times. ##EQU00002## then the welded joint (S1) is removed so as to obtain at least two intermediate cold-rolled sheets. Then the two intermediate cold-rolled sheets are butt welded, so as to create a welded joint (S2), the direction of which is perpendicular to the direction of hot rolling, then the assembly of the at least two intermediate cold-rolled and welded sheets is cold-rolled, in a step (L2), to the final thickness e.sub.f, the direction (DL.sub.2) of the cold rolling step (L2) coinciding with the direction of rolling (DL.sub.1).