SU1328016A1 - Working roll of rough sheet-rolling stand - Google Patents

Abstract

The invention relates to rolling production, in particular, to stand equipment, and can be used on universal broadband and hot rolling mills. The purpose of the invention is to improve the quality of the metal and increase the service life of the rolls. On the work roll, along an undulating pattern, annular grooves of varying depth are made, which increase. 2 Il. 1 tab. (L with IND 00 O5

Description

The invention relates to rolling production, in particular, to equipment for a rough sheet rolling mill, and can be used on universal, broadband and plate mills for hot rolling.

The purpose of the invention is to improve the quality of the rolled metal and increase the service life of the rolls.

The roll barrel is provided with annular grooves of variable depth increasing from the middle to the edge.

FIG. 1 shows the profiling of the work rolls of the sheet-rolling mill stand; in fig. 2 is a plot of pressure distribution along the length of a roll barrel

The peculiarity of the profiling of the work rolls is that the nature of the change in the depth of the annular grooves along the length of the barrel is taken to be the opposite of wear and deflection.

rolls.

I

 On the active part of the roll barrel (the length of the active part is determined by the maximum width of the rolled strips and sheets for each particular mill) with a step t is made of a series of coolant grooves along a wavy generatrix depth ht. increasing from the middle to the edges of the roll barrel. The minimum depth value h has a groove located in the middle of the roll barrel, and the maximum is at its edges. The contour of the roll gap, formed by a pair of rolls in the rolling plane, is symmetrical about the horizontal and vertical axes. The depth of the groove is determined by the maximum wear of the work rolls per radius for one set of rolls, and the number and amount of changes in the depth of the grooves are determined from the conditions for ensuring a uniform plot of specific metal pressures on the rolls along its length, which in turn ensures a reduction in deflection and more uniform roll wear.

The use of the developed {) 1x rolls in the roughing stand for the production of sheets and strips is based on uneven height deformation across the slab width in separate areas corresponding to the ridges and valleys of the rolls.

When rolling slab height He and width BO in the work rolls of the stand large reduction gets metal, deformed convex areas

(ridge) forming roll h

 H,

five

0

five

0

five

0

five

- of

(h p is the thickness of the roll at the exit of the cage in the areas corresponding to 1x ridges of rolls or troughs on the roll). The amount of compression slab areas of the roll valleys is reduced from the middle to the extreme grooves. In this case, at the site of the middle groove, the compression is maximum, and at the sites of the extreme grooves - the minimum. In the adjacent regions of the hollow-protrusion, conditions are created for the asymmetric deformation of a different sign, which grows from the middle to the edges of the roll barrel. The metal is displaced both in the longitudinal and in the transverse directions. The lateral friction forces in the zones corresponding to the wavy pitch are mutually opposite and increase from the middle to the extreme groove.

As the depth of the grooves increases from the middle of the roll to its edges, the area of contact of the metal with the roll increases from the middle to the edges of the roll barrel, as a result of which the metal pressure on the roll drops from the edges to the middle of the roll. The plot of the specific pressure along the length of the roll roll acquires a uniform character.

During the subsequent rolling of roll with a symmetric uneven in height. undulating profile in smooth rolls occurs a similar mechanism of deformation. Large compresses receive large convex areas, peals that increase from the middle to the edges of the roll barrel. Along with the longitudinal flow, the metal flows in the transverse direction on both sides of the projections. The mutually counterbalancing friction forces in the areas of the protrusion protrusions increase from the middle to the edges of the roll barrel. A symmetrical wave-like wave-like, different profile of the roll allows to obtain a uniform plot of specific pressures along the length of the roll barrel.

When rolling slabs in the proposed rolls, the integral altitude deformation across the width decreases from the middle to the edges of the barrel. During the subsequent rolling of a roll with a wave-shaped profile that is non-uniform in uneven height, in smooth rolls, the integral height deformation across the width is of equal and opposite character. The height distortion along the width of the roll flattens out.

The unevenness of the deformation rates of the sections along the width of the slab, which is rolled into rolls with a variable diameter along the length of the barrel, contributes to the separation of a part of the cracked scale. The same effect is obtained when rolling a roll with a symmetrical, uneven in height, wave-like profile in smooth rolls.

The alternating pattern of metal flow across the slab width (roll) during rolling in the suggested ones, and then in smooth rolls, increases the rolling out of surface defects and, consequently, the quality of the finished hot rolled sheets and strips.

In addition, when taking the slab, all the valleys of the rolls (grooves) are filled with metal, and the ridges (ridges) of the barrels reliably keep the slab from turning in the horizontal plane, thereby reducing the stability condition of the roll during the rolling process.

Example. Rolling a strip of 6x1420 mm in size from a slab of 175x1450xx4500mm in the roughing group of the stands of the 1700 continuous wideband hot rolling mill.

Work rolls are set up in the roughing mold, shaped on a wavy formation with annular grooves, the depth of which increases from the middle to the edges of the barrel in accordance with the indicated

by equation. The depth of the groove in the middle of the roll barrel is set to 4 mm. Considering the rolled slab, a uniform plot of specific pressures along the length of the roll drum is provided with n 4 grooves (without taking into account the groove in the middle of the extreme groove h, 8 mm).

The length of the roll barrel is 1700 mm with four annular grooves with a wavy pitch of t 160 mm, the base intensity factor Kg is 1.76, and the intensity ratio changes

depth of the groove to 7.05. By this equation, the depth of the grooves is determined.

The parameters of the profiled roll are shown in the table.

ten

15

The use of rolls in the hot-strip broadband mill line improves productivity by improving descaling.

Formula 3

The working roll of the rough sheet rolling mill, containing a barrel with a wavy generatrix and annular grooves on it, characterized in that, in order to improve the quality of the metal and increase the service life of the rollers, the annular grooves are made of variable depth. with an increase from the middle to the edge of the barrel in accordance with the equation

h, + K

flsii iz

 t f

where hg - the depth of the groove in the middle of the roll barrel; wavy pitch; the serial number of the step is a wavy generatrix, counting from the middle of the roll barrel; roll barrel length; the intensity factor of the depth of the grooves.

t

Lk

FIG. one

Editor V. Petrash

Compiled by M. Blagova

Tehred A. Kravchuk Proofreader M. Demchik

Order 3427/11 Circulation 480Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

FIG. 2

Claims (1)

Claim The work roll of the rough sheet rolling mill, containing a barrel with a corrugated generatrix and annular grooves on it, characterized in that, in order to improve the quality of the metal and increase the service life of the rolls, the annular grooves are made of variable depth, with an increase from the middle to the edge of the barrel in accordance with the equation H = ^h o ^{+ K} (-¾1 ² . where h ₀ is the depth of the groove in the middle of the roll barrel; t is the step of the wavy generatrix; p. - serial number of the wavy generatrix, counting from the middle of the roll barrel; L is the length of the roll barrel; K is the coefficient of intensity of changes in the depth of the grooves. FIG. 2