SU1342542A1 - Method of rolling plates - Google Patents

Abstract

The invention relates to rolling production, in particular to the rolling of thick plates. The purpose of the invention is to reduce the consumption of metal by trimming by eliminating the bulge along the width of the rolls. The heated slab is fed to the rolls of the roughing stand and is longitudinally rolled to obtain a roll length close to the length of the roll barrel. In the penultimate passage, the roll solution is set lower than the maximum variable reduction required at the end of the roll. The last pass is made in the opposite direction with variable compression, after which the roll is turned by 90 ° C. in the horizontal plane and produce a breakdown of the width. Then turn 90 and roll along to the thickness of the rolled on the commodity cage. Numbers | WITH/)

Description

113

The invention relates to rolling production, in particular to the rolling of thick sheets on reversing mills.

The purpose of the invention is to reduce the amount of metal to be cut by eliminating the bulge across the width of the roll.

Rolling is carried out as follows.

The heated slab is served by roller conveyor to the rolls of the roughing stand, and 2-4 longitudinal passes are made (first stretching) to obtain the length of the roll, close to the length of the roll barrel. In the pre | last pass of the first stretch; (i.e., in the first HLR third), the Yalk solution is set lower than the maximum variable reduction on the end of the roll (/ h. At the same time, the required main reduction Ah is set by the pressure screws of the electromechanical pressure device, and the maximum value of variable crimping cCh - plungers, located under the cushions of the lower roll of the hydraulic cylinders of the hydraulic pressure device. Due to the variable crimping of the front half, The middle aisle has a convex section of its anterior half-pina and a rectangular section of the back.

Before the last passage of the first stretch, the installation of the pressure screws is not changed (i.e., the main reduction), and the lower roller is moved upwards by an amount about b using the GNU. Then, the last pass of the first stretch in the opposite direction is performed with variable compression, as a result of which the back half acquires the same

convex profile, as well as front. Then the roll is turned 90 in a horizontal plane and a width breakdown is made.

In the first pass of the breakdown of the width of the compression of the edges by 2 (C;) more than the center of the roll. If the roll does not get a profile C that is convex in cross section on the Utonnye butts during the first stretching, the edges are more compressed by 2 ° C. Since the crown of the C-shaped profiling is required to eliminate the bulge across the width of this roll, concavity of the ends and, ultimately, concavity along the width of the rolls. By reducing the edge compression by cfh, they make the total non-uniformity of compression across the width of the roll when rolling with the boom max identical to the non-uniformity when rolling with the required arrow C ;, since

L c / h; + (U,

where cCh is the reduction of the thickness of the edges to compensate for the difference in their reduction during rolling in rolls with a concavity boom compared to the required boom C; :

c / h, 2 (,, - C ,.);

reducing the thickness of the edges to compensate for the greater relative deformation of the edges when rolling with the Sddax boom compared to rolling with the C, -. From the condition of equality of relative deformations in the center of the roll and at the edges receive

c / h2 2 (C „“, eC, -) / C ,,

where ih is the total absolute compressed .e when splitting the width.

cfb

mm;

H.thickness of the edges of the roll after the breakdown of the width, mm. After transformations are found. L 2 (, е-С.), G, where is the stretch ratio at

breakdown widths.

In the remaining aisles, the widths are broken down due to the cross section of the roll forming of the roll-over gap with the boom C, compression is set equal in the width of the roll, and non-uniform stretching in width is caused by less than 2 (C.) edge thickness compared to the center. This uneven stretching is compensated by c / hj in the first pass.

After splitting the width of the roll by

rolled 90 in the horizontal plane and rolled along (second stretching) to the thickness of the rolled, on the finishing stand. Then the roll is transferred by a roller table to the finishing stand and dock to the thickness of the sheet.

PRI m e, p. On a mill 2800, a sheet of 10X2500X600 mm is rolled from a slab of 210X700X1840 mm. The experimentally found concavity arrow of the parabolic profiling of the rolls of the roughing stand is necessary to eliminate the maximum bulge width for a given mill, 300 mm wide, equal to С 3.8 mm. In the case of rolling in cylinders with cylindrical profiling this The peal has L 275 mm (i.e., 25 mm less c / b, which corresponds to the minimum allowable gradation of cursors for 2500.mm sheets according to GOST). Required to remove c / b, 275 mm arrow concavity rolls Cj 3.5 mm. Stretch ratio during stretching. Then, the maximum value of the variable reduction at the end of the roll is equal to c / h of 2.3 mm, where IJL 3.86 is the stretch ratio when breaking down the width. Consequently, the ratio to the thickness of the roll is 0.01, which corresponds to the lower limit of variation of this parameter.

The proposed method eliminates the bulge across the width of the roll and, therefore, reduces the consumption of metal with trimming.

Claims (1)

Invention Formula Method of rolling thick sheets, including rolling in roughing stand 0 in rolls with concave parabolic profiling, breakdown of slab width Editor N.Rogulich Order 4545/6 Compiled by V. Vasiliev Tehred L. Serdyukova Proofreader M. Maksimishinets Circulation 480Subscribe VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab. 4/5 . Production and printing company, Uzhgorod, Projecto st., 4 O 5 0 five 0 and subsequent rolling in the finishing stand, differing in the fact that, in order to reduce the metal consumption by cutting, by eliminating the widening of the width of the roll, rolling in the roughing stand in the penultimate pass leads to variable compression, increasing the roll solution from the front end of the roll to the middle of 0.01-0.1 of its thickness, based on the ratio Vh 2 (, ks- S.) 2 where d h is the maximum amount of compression at the end of the roll, mm; "Ax boom the concavity of the roll forming roll of the roughing stand, ensuring the elimination of the maximum for the given mill of the convexity across the width of the rolls, mm; Cj is the arrow of the concavity of the rolls of the roughing stand, which is necessary to eliminate the bulge across the width of this roll, mm; | C - stretch ratio at breakdown width, and in the last pass - with compression, increasing the roll solution by the value of the difference in thickness between the middle of the roll and its front end in the penultimate pass.