Sixth order actuator and mill set-up system for rolling mill profile and flatness control
AssigneeAlcoa Inc.
InventorMark E. Puda
Life of this patent
Estimating the term…
Abstract
A rolling mill stand having a pair of side shiftable rolls defining a roll gap profile therebetween varying along the length of the rolls according to a sixth order polynomial equation. The flatness of the strip exiting the rolling mill stand is controlled by determining the temperature profile of the rolls and adjusting the side shift positions of the rolls to compensate for the expansion of the rolls due to changes in the temperature of the rolls.
Claims15
In a rolling mill stand having a pair of rolls axially slidable relative to each other and being configured to reduce a moving strip of metal in a roll gap between the rolls, wherein a variable roll gap profile is adjustable by axially shifting the rolls, the improvement comprising:
- each roll having a ground roll profile wherein the diameter of each roll varies along the length of the roll according to the seventh order equation
- D(ZR)=C0+AZR+BZR2+CZR3+DZR4+EZR5+FZR6+GZR7
- wherein ZR is the normalized distance across the length of the face of the roll measured from the center of the roll.
In a rolling mill stand having a pair of rolls axially slidable relative to each other and being configured to reduce a moving strip of metal in a roll gap between the rolls, wherein a variable roll gap profile is adjustable by axially shifting the rolls, the improvement comprising:
- the variable roll gap profile varies along the length of the rolls according to the sixth order equation
- RPG(ZM,S)=(HS+I)ZM2+(JS+K)ZM6
- wherein
- ZM is the normalized distance from mill center line;
- and
- S is the normalized roll side shift position.
A method of controlling flatness of a strip rolled in a rolling mill stand comprising the steps of
- (a) providing a pair of side shiftable work rolls to form a gap therebetween, each roll having a ground roll profile wherein the diameter of each roll varies along the length of the rolls according to the seventh order equation
- D(ZR)=C0+AZR+BZR2+CZR3+DZR4+EZR5+FZR6+GZR7
- wherein ZR is the normalized distance across the length of the face of the roll measured from the center of the roll;
- (b) rolling a strip between the rolls;
- and
- (c) axially shifting the rolls between a maximum side shift position and a minimum side shift position such that the gap between the rolls varies along the length of the rolls according to the sixth order equation
- RPG(ZM,S)=(HS+I)ZM2+(JS+K)ZM6
- wherein
- ZM is the normalized distance from mill center line;
- and
- S is the normalized roll side shift position.
Dependencies are inferred from the claim text.