A roller stand (1) that has a roller stand frame (3) in which working rollers (4, 5), or working rollers (4, 5) and support rollers (8, 9), or working rollers (4, 5), intermediate rollers (10, 11), and support rollers (8, 9) are mounted. Each roller (4, 5, 8, 9, 10, 11) can be rotated about a respective rotational axis (6, 7). In a roller stand (1) without intermediate rollers (10, 11), the working rollers (4, 5) can be moved relative to one another in the direction of the respective rotational axis (6, 7), i.e. axially. In a roller stand (1) with intermediate rollers (10, 11), the same applies to the working rollers (4, 5) or the intermediate rollers (10, 11). Each of the axially movable rollers (4, 5 or 10, 11) has an effective barrel length (L) and a curved contour (R1, R2) which extends over the entire effective barrel length (L). Each of the axially movable rollers (4, 5 or 10, 11) has a contour (R1, R2) made by superimposing a respective base function (B1, B2) with a respective additional function (Z1, Z2). The base functions (B1, B2) and the additional functions (Z1, Z2) are functions of the location (x) in the direction of the respective rotational axis (6, 7). The base functions (B1, B2) are determined so as to complement each other in a specified relative axial position in an unloaded state of the axially movable rollers (4, 5 or 10, 11) and form a convex or concave roller gap profile depending on a movement direction upon being moved from the axial position. The sum of the additional functions (Z1, Z2) is a symmetrical function, which is monotonous on both sides, with respect to the barrel center of the axially movable rollers (4, 5 or 10, 11) in the unmoved state.

A method ascertains control variables for active profile and flatness control elements for at least one rolling stand for hot rolling metal strip with a plurality of i=1 . . . I successive passes and for ascertaining profile and center flatness values for the hot-rolled metal strip. The occurrence of fluctuations in the center flatness of the metal strip after the individual passes and the resulting disadvantages for the rolling stability and the product quality are prevented. The method provides that, also for the target center flatness of the metal strip after a predetermined pass k with i=1 . . . <k< . . . I and for the target center flatness after the subsequent passes, pass-specific interval ranges are also specified in each case, and in that the successive calculation of the control variables and profile values is then carried out taking into account such additional specifications as well.

The present invention relates to a method and an apparatus for changing the effective contour of a running surface (8) of a working roller (3, 4) during the hot rolling of rolling stock in a roll stand (2) to form a rolled strip (1). The intention is to be able to change the contour of the running surface (8) during the hot rolling by means of the invention. This object is achieved according to the invention by the axial displacement of the working rollers (3, 4) in opposite directions by a displacement distance s, wherein s is greater or less than $\frac{r}{\tan \left(\right)}$
and r indicates the wear of the running surface (8) in the radial direction (R) and indicates the pitch angle of the conical portion (7) of the respective working roller (3, 4).

Mill rolls capable of rolling long kilometers used for ESP production line and a method for rolling long kilometers using the mill rolls. The mill rolls include rolls (3, 4), a bearing box (2) and a roll shifting hydraulic cylinder (1), wherein the middle portion of the surface of the roll sinks inwards, one end of the rolls is frustum-shaped, smaller and smaller outwards, so that the roll surface forms a compensation ramp, and the other end of the rolls is cylindrical. The upper roll (3) and the lower roll (4) have the same roll profile and are positioned in the opposite direction. The mill rolls are characterized by reduced runaway of the rolled product and a longer service life.

A method of controlling a roll gap between first and second work rolls (102, 104) that includes defining a plurality of work surface locations spaced apart along the first work roll (102) in the longitudinal direction; obtaining a radius of the work surface (102a) of the first work roll (102) at each of the work surface locations; based on the radii of the work surface locations, obtaining a longitudinal profile of the work surface (102a); based on the longitudinal profile, tilting the first work roll (102) relative to the second work roll (104) in the common plane in order to reduce a difference in the average size of the gap either side of a centerline (CL), which bisects the longitudinal axes of the first and second work rolls (102, 104).

The present invention relates to a method and an apparatus for changing the effective contour of a running surface (8) of a working roller (3, 4) during the hot rolling of rolling stock in a roll stand (2) to form a rolled strip (1). The intention is to be able to change the contour of the running surface (8) during the hot rolling by means of the invention. This object is achieved according to the invention by the axial displacement of the working rollers (3, 4) in opposite directions by a displacement distance s, wherein s is greater or less than ?r/tan(?) and ?r indicates the wear of the running surface (8) in the radial direction (R) and ? indicates the pitch angle of the conical portion (7) of the respective working roller (3, 4).

Disclosed is a skew rolling assembly suitable for large-size superalloy bars, including four rollers with completely identical shape and size, where the four rollers are all active rollers. In the production process, the four rollers play a role in promoting the forward flow of blank metal in a rolling direction, thus avoiding a rolling jamming phenomenon caused by the obstruction of guide plates to the forward flow of the blank in the rolling process of the prior art. The providing of the four rollers improves the rolling speed and increases the degree of deformation. Disclosed is a skew rolling method suitable for large-size superalloy bars. By utilizing the skew rolling assembly suitable for the large-size superalloy bars, and utilizing four rotating active rollers for the skew-rolling forming of bars, the rolling speed is improved, the problem that the cooperative rolling of two rollers and guide plates in the prior art is prone to the phenomenon of rolling jamming is avoided, the forming quality is guaranteed, the rolling production efficiency is improved, and the degree of deformation is increased.

A compensation method of an asymmetric strip shape of a strip rolling mill, for compensating the asymmetric strip shape of a strip caused in a machining process of the strip rolling mill in the prior art. The compensation method is realized by generating a non-linear asymmetric no-load roll-shaped profile curve through polishing an upper working roll and a lower working roll of a rolling mill and forming a non-linear asymmetric no-load roll gap between a transmission side and a working side of the upper and lower working rolls. The strip rolling mill in the prior art refers to a presently commonly used two-roll rolling mill driven by the transmission side of the working roll, a four-roll rolling mill equipped with a support roll and a multi-roll rolling mill equipped with a middle roll.

A roller stand (1) that has a roller stand frame (3) in which working rollers (4, 5), or working rollers (4, 5) and support rollers (8, 9), or working rollers (4, 5), intermediate rollers (10, 11), and support rollers (8, 9) are mounted. Each roller (4, 5, 8, 9, 10, 11) can be rotated about a respective rotational axis (6, 7). In a roller stand (1) without intermediate rollers (10, 11), the working rollers (4, 5) can be moved relative to one another in the direction of the respective rotational axis (6, 7), i.e. axially. In a roller stand (1) with intermediate rollers (10, 11), the same applies to the working rollers (4, 5) or the intermediate rollers (10, 11). Each of the axially movable rollers (4, 5 or 10, 11) has an effective barrel length (L) and a curved contour (R1, R2) which extends over the entire effective barrel length (L). Each of the axially movable rollers (4, 5 or 10, 11) has a contour (R1, R2) made by superimposing a respective base function (B1, B2) with a respective additional function (Z1, Z2). The base functions (B1, B2) and the additional functions (Z1, Z2) are functions of the location (x) in the direction of the respective rotational axis (6, 7). The base functions (B1, B2) are determined so as to complement each other in a specified relative axial position in an unloaded state of the axially movable rollers (4, 5 or 10, 11) and form a convex or concave roller gap profile depending on a movement direction upon being moved from the axial position. The sum of the additional functions (Z1, Z2) is a symmetrical function, which is monotonous on both sides, with respect to the barrel center of the axially movable rollers (4, 5 or 10, 11) in the unmoved state.

[Object] To suppress occurrence of shape defects in a material to be rolled and enable efficient and stable production of an H-shaped steel product with a flange width larger than a conventional flange width by creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending formed flange portions.

[Solution] Provided is a method for producing H-shaped steel, the method including: a rough rolling step; an intermediate rolling step; and a finish rolling step. In a rolling mill that performs the rough rolling step, a plurality of calibers to shape a material to be rolled are engraved, the number of the plurality of calibers being four or more. Shaping of one or a plurality of passes is performed on the material to be rolled in the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a second caliber and subsequent calibers among the plurality of calibers, reduction is performed in a state where end surfaces of the material to be rolled are in contact with caliber peripheral surfaces in shaping of at least one pass. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed.