Abstract When rolling a steel slab along its edges to reduce its width the head end of the slab may experience a larger percentage reduction than the mid portions of the slab. A similar situation, but to a less marked extent may occur at the tail end of the slab. To avoid this disadvantage workpieces are rolled in a vertical mill stand and the roll gap of the mill stand is automatically controlled during rolling. In the combination of a vertical mill stand and a horizontal mill stand in which slabs are successively edge and flat rolled an automatic control system is employed to control means for adjusting the roll gap of the vertical stands during the rolling of at least a terminal length of the slab adjacent an end so as to produce a width profile such that after subsequent horizontal rolling the width of the terminal length is not less than the width of the remainder of the slab.
A method of rolling a metal slab which comprises the steps of first edge rolling said slab in a vertical mill stand while progressively decreasing the roll gap of said vertical mill stand as a first portion of said slab passes therethrough to impart a selected width profile to said first portion, maintaining said roll gap substantially constant during the edge rolling of at least the major part of the remainder of said slab, subsequently flat rolling said slab in a horizontal mill stand, and so selecting said width profile that after said subsequent horizontal flat rolling the width of said first portion of said slab is at least as great as that of said major part of said slab.
Claim 2
Independent Claim
120 words
A method of rolling a metal slab which comprises the steps of first edge rolling said slab in a vertical mill stand while progressively decreasing the roll gap of said vertical mill stand as a first portion of said slab passes therethrough to impart a selected width profile to said first portion, maintaining said roll gap substantially constant during the edge rolling of at least the major part of the remainder of said slab, subsequently flat rolling said slab in a horizontal mill stand, and so selecting said width profile that after said subsequent horizontal flat rolling the width of said first portion of said slab is at least as great as that of said major part of said slab.
Claim 3
Dependent Claim
58 words
A method as claimed in claim 1 which also comprises the step of increasing said rolling gap as the last portion of said slab passes through said vertical mill stand so that after said subsequent horizontal flat rolling the width of said last portion of said slab is at least as great as that of said major part.
Claim 4
Dependent Claim
22 words
A method of rolling a metal slab as claimed in claim 1 in which said roll gap is decreased at constant speed.