Tail edge board thickness control manner null of tandem

摘要

PURPOSE:To remove the plate thickness variation at plate drawing time by adding the correction amount in controlling a rolling reduction to the rolling reduction control output of a front step rolling mill at the output timing of a tracking circuit before a fixed distance from the plate drawing time from a rolling mill. CONSTITUTION:The rolling reduction position of a 1st rolling mill 2 is controlled in a closing direction by the rolling reduction control correction amount immediately before a plate passing the 1st rolling mill 2. It is possible to relax the abrupt tension variation caused at the time when the above plate passes through the 1st rolling mill 2 in advance due to the front tension T12 being reduced. As a result, the impact-up of the speed of a 2nd rolling mill 3 is reduced and the speed variations of a rear step 3rd rolling mill 4, a 4th rolling mill 5 become so small as to be neglectable. The abrupt variation between the 2nd, 3rd rolling mills at the plate drawing time of the 1st rolling mill 2 is reduced and the abrupt plate thickness variation of the 3rd rolling mill 4 outlet side plate thickness can be reduced.