A method for dynamic roll gap control for flexible rolling of metallic strip material can include: defining a nominal thickness profile with defined nominal corner points and with profile sections lying in between, wherein two profile sections adjoining a nominal corner point each have different average gradients; flexible rolling of the strip material according to the nominal thickness profile; measuring an actual thickness profile of the flexibly rolled strip material; determining actual corner points corresponding to the nominal corner points and actual intermediate points corresponding to the nominal intermediate points; determining corner point comparison values from the nominal corner points and the corresponding actual corner points, as well as intermediate point comparison values from the nominal intermediate points with the corresponding actual intermediate points; controlling a roll gap depending on the corner point comparison values and the intermediate point comparison values.

A method for dynamic roll gap control for flexible rolling of metallic strip material can include: defining a nominal thickness profile with defined nominal corner points and with profile sections lying in between, wherein two profile sections adjoining a nominal corner point each have different average gradients; flexible rolling of the strip material according to the nominal thickness profile; measuring an actual thickness profile of the flexibly rolled strip material; determining actual corner points corresponding to the nominal corner points and actual intermediate points corresponding to the nominal intermediate points; determining corner point comparison values from the nominal corner points and the corresponding actual corner points, as well as intermediate point comparison values from the nominal intermediate points with the corresponding actual intermediate points; controlling a roll gap depending on the corner point comparison values and the intermediate point comparison values.

A roll stand with at least one working roll for rolling strip material and with a hydraulic arrangement for controlling a roll gap of the roll stand, comprises at least one hydraulic adjustment unit for adjusting the roll gap, the hydraulic adjustment unit comprising a cylinder and an adjusting piston dividing the cylinder into a first chamber and a second chamber; a first double-acting valve arrangement and a second double-acting valve arrangement which are each connected to the first chamber and the second chamber for variable control of the adjusting unit, wherein the second double-acting valve arrangement is connected in parallel with the first valve arrangement and has a larger nominal volume flow than the latter; and wherein the adjusting unit can be pressurized with an working pressure of more than 200 bar.

A roll stand with at least one working roll for rolling strip material and with a hydraulic arrangement for controlling a roll gap of the roll stand, comprises at least one hydraulic adjustment unit for adjusting the roll gap, the hydraulic adjustment unit comprising a cylinder and an adjusting piston dividing the cylinder into a first chamber and a second chamber; a first double-acting valve arrangement and a second double-acting valve arrangement which are each connected to the first chamber and the second chamber for variable control of the adjusting unit, wherein the second double-acting valve arrangement is connected in parallel with the first valve arrangement and has a larger nominal volume flow than the latter; and wherein the adjusting unit can be pressurized with an working pressure of more than 200 bar.

The seamless pipe in which a thin-walled portion in a pipe circumferential direction is formed in a pipe axial direction, in which a line segment formed by connecting one end and the other end of the thin-walled portion along a pipe surface with a shortest distance in a formation direction of the thin-walled portion is inclined at an angle α of 5.0° or more with respect to the pipe axial direction. It is preferable that one end and the other end of the thin-walled portion are set from a region in a pipe selected with a shorter length between a length of 1.0 m in the pipe axial direction and 90% of a length in the pipe axial direction where the thin-walled portion turns once in the pipe circumferential direction.

An apparatus, computer program product, and method provide for increased economy in maintaining working and backup rollers that are used to producing sheet metal of uniform thickness. Left and right necks of the roller are supported and rotated. A radial measurement is made of left and right necks to calculate a center of rotation of each neck. Radial positions of reference spheres centered at each end that define a gage reference line (GRL) are measured. Material is removed from the necks to not only increase roundness but also to move the center of rotation of each neck toward the GRL, enabling grinding/machining of a body portion of the roller to restore roundness with reduced waste of material.

An apparatus, computer program product, and method provide for increased economy in maintaining working and backup rollers that are used to producing sheet metal of uniform thickness. Left and right necks of the roller are supported and rotated. A radial measurement is made of left and right necks to calculate a center of rotation of each neck. Radial positions of reference spheres centered at each end that define a gage reference line (GRL) are measured. Material is removed from the necks to not only increase roundness but also to move the center of rotation of each neck toward the GRL, enabling grinding/machining of a body portion of the roller to restore roundness with reduced waste of material.

A rolling mill is provided with: a roll for rolling a metal plate, the roll being capable of shifting in an axial direction and having a tapered portion at an end portion in the axial direction; and a heating unit configured to form an expansion portion protruding in a radial direction in the tapered portion by heating the tapered portion.

A rolling mill is provided with: a roll for rolling a metal plate, the roll being capable of shifting in an axial direction and having a tapered portion at an end portion in the axial direction; and a heating unit configured to form an expansion portion protruding in a radial direction in the tapered portion by heating the tapered portion.

A controller (2) and method for controlling a stretch-reducing mill (1) for rolling tubes are presented. The stretch-reducing mill (1) has several roll stands (10) arranged behind one another in a conveying direction (F) of the tubes (R) and at least one outlet-side wall thickness measuring device (20). The controller (2) is set up to receive measurement data from the wall thickness measuring device (20) which identifies one or more outlet-side wall thicknesses (s.sub.r) of a tube (R) exiting from the last roll stand (10) and one or more of the received measurement data wall thickness on the inlet-side (s.sub.l_t), preferably to determine an inlet-side wall thickness profile of the tube (R) before entering the first roll stand (10), and preferably to calculate and control one or more of the roll stands (10), taking into account the determined inlet-side wall thicknesses (s.sub.l_t).