Continuous spiral motion system for rolling mills

A system for improving properties of a metal strip during rolling between rotating upper and lower work rolls in a mill stand, including mill housing posts, for reducing work roll edge wear, for improving distribution of thermal expansion of the work roll during rolling, for reducing required rolling torque for achieving a particular strip thickness reduction, and for increasing the tonnage of rolled strip between roll changes, comprising means to continuously shift the rotating work rolls during rolling to impart a spiral motion to the work rolls, and means to online grind, heat reharden and cool the work rolls with such grinding, rehardening and cooling means being located outside at least one such mill housing post of the mill stand.

A system for spiral rolling of an elongated strip in a rolling mill stand, including mill housing posts, comprising at least one pair of upper and lower work rolls, each of which is of a length substantially greater than a width of a strip to be rolled, means to rotate the work rolls in a circular motion during rolling, and means to continuously axially shift the rotating work rolls during a rolling cycle in which, at a beginning of the cycle, the strip is rolled between opposite first end portions of the work rolls and, as the cycle continues, between progressively more centrally located portions of the work rolls and then between less centrally located portions of the work rolls, and, at the end of the cycle, between opposite second end portions of the work rolls, such system further comprising a roll grinder located outside at least one of the mill housing posts, online with and movable toward and away from a corresponding work roll, to grind the work roll after an initial hardened layer of the work roll has been removed in rolling the strip, without removal of the work roll from the mill stand.

A method of rolling elongated metal strip between rotating upper and lower work rolls in a rolling mill stand, including mill housing posts, comprising providing work rolls of a length substantially greater than a width of a strip to be rolled, and continuously axially shifting the rotating work rolls to impart thereto a spiral motion with respect to the strip being rolled and a three dimensional deformation of the strip during rolling, thereby reducing the magnitude of applied rolling torque required for a particular strip thickness reduction, improving physical properties of the rolled strip, reducing edge wear of the work rolls, and improving even distribution of work roll thermal expansion during rolling as compared to conventional rolling with rotating work rolls without such continuous work roll shifting, such method further comprising after substantial loss of work roll initial hardened surface, online grinding, heat rehardening and cooling of a work roll performed outside the mill housing posts of the rolling mill stand, whereby tonnage of strip rolled between roll changes is substantially increased as compared to conventional online grinding of a work roll between drive side and operator side mill housing posts of the mill stand.

A method for improving properties of a metal strip during rolling between rotating upper and lower work rolls in a mill stand, including mill housing posts, for reducing work roll edge wear, for improving distribution of thermal expansion of the work roll during rolling, for reducing required rolling torque for achieving a particular strip thickness reduction, and for increasing the tonnage of rolled strip between roll changes, comprising continuously shifting the rotating work rolls during rolling to impart a spiral motion to the work rolls, and online grinding, heat rehardening and cooling of the work rolls, with such operations being performed outside mill housing posts of the mill stand.

A method for spiral rolling of an elongated strip in a rolling mill stand, including mill housing posts, having at least one pair of upper and lower work rolls, comprising providing work rolls each of which is of a length substantially greater than a width of a strip to be rolled, rotating the work rolls in a circular motion during rolling, and continuously axially shifting the rotating work rolls during a rolling cycle in which, at a beginning of the cycle, the strip is rolled between opposite first end portions of the work rolls and, as the cycle continues, between progressively more centrally located portions of the work rolls and then between less centrally located portions of the work rolls, and, at the end of the cycle, between opposite second end portions of the work rolls, such method further comprising online grinding, heat rehardening and cooling of the work rolls outside said mill housing posts of the mill stand.