Abstract A method is set forth for use in crown control in a multi-roll rolling mill, the method including the steps of: setting in advance a shape of a thermal crown of a work roll corresponding to various rolling conditions and a changing gradient of a mechanical crown for each rolling speed zone applied to a work roll which is determined according to a change in time of a thermal crown relative to a change in rolling speed; applying a roll bending force, as an initial value, to the work roll, controlling the roll bending force from the thermal crown shape and an initial value of a mechanical crown amount at a suitable position of the work roll which is determined from an expected rolling schedule and a target mechanical crown amount at a standing speed; detecting the rolling speed; selecting the changing gradient of the mechanical crown according to the rolling speed zone at that time; and at the same time adjusting the roll bending force applied to the work roll.
A crown method in a multiroll rolling mill, which comprises: setting in advance a plurality of shapes of a thermal crown of a work roll corresponding to a mechanical crown applied to a work roll; applying a roll bending force, as an initial value, to the work roll; controlling said roll bending force from said thermal crown shape and an initial value of a mechanical crown amount at a suitable position of the work roll determined from a predetermined rolling schedule and a target mechanical crown amount at a standing speed; detecting the rolling speed; selecting a changing gradient of said mechanical crown amount according to a rolling speed zone at that time; and simultaneously adjusting the roll bending force applied to the work roll.
Claim 2
Dependent Claim
125 words
A crown method in a multiroll rolling mill, which comprises: setting in advance a plurality of shapes of a thermal crown of a work roll corresponding to a mechanical crown applied to a work roll; applying a roll bending force, as an initial value, to the work roll; controlling said roll bending force from said thermal crown shape and an initial value of a mechanical crown amount at a suitable position of the work roll determined from a predetermined rolling schedule and a target mechanical crown amount at a standing speed; detecting the rolling speed; selecting a changing gradient of said mechanical crown amount according to a rolling speed zone at that time; and simultaneously adjusting the roll bending force applied to the work roll.