Changing the effective contour of a running surface of a working roll during hot rolling of rolling stock in a roll stand to form a rolled strip

A method for reducing an effective contour of a running surface of a working roller during hot rolling of rolling stock in a roll stand to form a rolled strip, wherein the roll stand comprises:

• an upper working roller and a lower working roller, wherein each working roller has two ends for the rotational mounting of the working roller in chocks;
• wherein in the axial direction, each working roller in the roll stand extending in respective opposite directions has a conical portion followed by a running surface;
• wherein running surfaces of each of the working rollers in the roll stand have a non-cylindrical initial contour prior to the hot rolling;
• wherein in the roll stand, the upper working roller is fitted in the opposite direction to the lower working roller;
• wherein each working roller has a respective displacing device operable for axially displacing the working rollers in the roll stand in respective opposite directions;
• comprising the method steps of:
• hot rolling of the rolling stock between the two working rollers, wherein the radial extent of the running surface of a working roller decreases at a rate of {dot over (Δ)}r during the rolling;
• and
• reducing the effective contour of the running surfaces of the working rollers during hot rolling of rolling stock by axially displacing the working rollers in opposite axial directions at a displacement rate of
• v
• ≡
• s
• .
• >
• Δ
• ⁢
• ⁢
• r
• .
• tan
• ⁢
• ⁢
• (
• α
• )
• ,
• where {dot over (Δ)}r indicates me rate of wear of the running surface in the radial direction (R) and α indicates the pitch angle of the conical portion of the respective working roller, wherein the effective contour of the running surface of each working roller is the contour that the running surface of the working roller (which is not axially displaced during the hot rolling) would have to have so that a determined profile or a determined planarity for the rolled strip is produced during the hot rolling of rolling stock.

A method for increasing an effective contour of a running surface of a working roller during hot rolling of rolling stock in a roll stand to form a rolled strip, wherein the roll stand comprises:

• an upper working roller and a lower working roller, wherein each working roller has two ends for the rotational mounting of the working roller in chocks;
• wherein in an axial direction, each working roller in the roll stand in respective opposite directions has a conical portion followed by a running surface;
• wherein running surfaces of each of the working rollers in the roll stand have a non-cylindrical initial contour prior to the hot rolling;
• wherein in the roll stand, the upper working roller is fitted in the opposite direction to the lower working roller;
• wherein each working roller has a respective displacing device operable for axially displacing the working rollers in the roll stand in respective opposite directions;
• comprising the method steps of:
• hot rolling of the rolling stock between the two working rollers, wherein the radial extent of the running surface of a working roller decreases by Δr during the rolling;
• and
• increasing the effective contour of the running surfaces of the working rollers by axially displacing the working rollers in opposite axial directions by a displacement distance
• 0
• <
• s
• <
• Δ
• ⁢
• ⁢
• r
• tan
• ⁢
• ⁢
• (
• α
• )
• ,
• where Δr indicates the wear of the running surface in the radial direction (R), and α indicates the pitch angle of the conical portion of the respective working roller, wherein the effective contour of the running surface of each working roller is the contour that the running surface of the working roller (which is not axially displaced during the hot rolling) would have to have so that a determined profile or a determined planarity for the rolled strip is produced during the hot rolling of rolling stock.

A method for increasing an effective contour of a running surface of a working roller during hot rolling of rolling stock in a roll stand to form a rolled strip, wherein the roll stand comprises:

• an upper working roller and a lower working roller, wherein each working roller has two ends for rotational mounting of the working roller in chocks;
• wherein in the axial direction, each working roller in the roll stand has a conical portion followed by a running surface;
• wherein running surfaces of each of the working rollers in the roll stand has a non-cylindrical initial contour prior to the hot rolling;
• wherein in the roll stand, the upper working roller is fitted in the opposite axial direction to the lower working roller;
• wherein each working roller has a respective displacing device operable for axially displacing the working roller;
• comprising the method steps of:
• hot rolling of the rolling stock between the two working rollers, wherein the radial extent of the running surface of a working roller decreases at a rate of wear {dot over (Δ)}r during the rolling;
• and
• increasing the effective contour of the running surfaces of the working rollers by axially displacing the working rollers in opposite axial directions at a displacement rate of
• 0
• <
• v
• ≡
• s
• .
• <
• Δ
• ⁢
• ⁢
• r
• .
• tan
• ⁢
• ⁢
• (
• α
• )
• ,
• where {dot over (Δ)}r indicates the rate of wear of the running surface in the radial direction (R) and α indicates the pitch angle of the conical portion of the respective working roller, wherein the effective contour of the running surface of each working roller is the contour that the running surface of the working roller (which is not axially displaced during the hot rolling) would have to have so that a determined profile or a determined planarity for the rolled strip is produced during the hot rolling of rolling stock.