SU1405913A1 - Slab for manufacturing strips - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular, to sheet-rolling production, and can be applied in the preparation of strips, preferably in broadband hot rolling mills (SHGGP). The purpose of the invention is to reduce the expenditure ratio of the metal due to the reduction of trimming by reducing the defect in the form of an end roll like fishtail. The slab is made with straight side faces 2. The end faces 3 have a straight line section and curvilinear sections, which are made along the curve described by equation (1). In the case of slab rolls, due to the fact that the width of the front end is smaller due to the presence of curved sections, the slab is captured without dynamic loads. When rolling the back end of the slab, the volume of the metal mixed in the longitudinal direction decreases due to the profiled sections. When compressing the slab, the unwinding acquires a rectangular shape in plan. 2 Il. 1 tab. (Oh (L

Description

I /

7

SP

WITH

with

The invention relates to the processing of metals by pressure, in particular to sheet-rolling production, and can be applied in the preparation of strips, preferably in broadband hot rolling mills (SHSGP).

The purpose of the invention is to reduce the expenditure ratio of the metal as a result of the reduction of trimming by reducing the defect in the form of an end roll like fishtail.

FIG. 1 presents the proposed slab, obsh, iyi view; in fig. 2 - the same plan (view of the wide edge).

SL b for the production of strips has two flat large 1, two lateral 2

Kie load at capture. When rolling the back end (front in the previous pass), the displaceable metal fills a part of the remaining free volume. When the slab is compressed to the required value in several passes, the displaced metal completely fills the free object at the front and rear ends and the roll out acquires a rectangular shape in plan, which ensures a reduction in the end cut and a reduction in the expenditure ratio.

Sequential rolling in several vertical stands in one direction. The slb is set to vertical rolls with a profiled end. Due to

faces (AB and SD), made in accordance with the formula

v

9 1} / a j-),

that its width CB is B-2a

and two end 3 faces, each with a curve — it takes the slab to be without dynamic, is adjacent to all face and lateral loads. During the rolling of the rear end of the slab, the volume of the metal decreases due to the profiled sections, which fills part of the free volume of ABEHGF 2Q in the same way as when rolling the slab in subsequent vertical cages. After cutting the slab to the required width, its rear end has a rectangular shape in plan, and the front end is somewhat narrower than the main part. In order to eliminate the formation of 25 nodules in the rolling process in the vertical rolls, the dog bone is thickened and the fishtail is converted into a roll in the form of a fish tail after being squeezed in horizontal rolls at the ends of the slabs, both

where y is the current slab width, varying from y (B - 2a) at the end of the slab to and from y on the length 1 from the end, mm; B — width of slab, mm; a is the length of the curved section along the end face of the slab, which varies from within С

AB

before

at.

(DV - total compression; its front parts are made from the right along the width; From 1.5-2.0; d by coal sections, conjugated with more (0.4-0.7), mm; X is the current coordinate, varying from 0 to 1, mm;

1 is the length of the curvilinear section along the lateral face of the slab, applying in the range from 0.51d to 3 Id (Id is the projection of the length of the arc of capture on the axis OX when rolling in vertical rolls), mm; n-exponent (0,, 0),

 Id VR db

where R is the radius of the vertical rolls, mm. To clarify the rolling of the proposed slab, it is necessary to consider the following modes: reverse rolling in an edger stand and sequential rolling in 35

edges on the curvilinear dependence established from the expression (1). The expediency of choosing this expression (1) of parabolic type is explained by the fact that it most closely approximates the experimental data obtained in the simulation of the formation of slab ends to reduce the length of the roll and reduce the expenditure ratio. Structurally, it consists of constant 40 values: B, 2a, 1, and n, as well as variable X. For the same word, characterized by center B, the parameters 2a, 1, and n are variable and are the amount of compression slab

across the width and the parameter x changes to

how many vertical cages in the same length of the curviline: the yoy section along the lateral direction. The edges are from 0 to 1. At the same time, the length a is curved. Reverse rolling in the edger stand of the linear section along the end face of the slab Сл b is set by the profiled end chosen from C - - to AVSD in vertical rolls. Due to the fact that its width at the CB end face is equal to B-2ai n, is the total compression of the slab by

it provides for capturing slab without dynamic loads. When rolling the back end of the slab, the volume of the metal displaced in the longitudinal direction and which

50

width; C 1.5-2.0, d 0.4-0.7). The minimum value of a C- ensures the absence of local broadening on the tire pass fills a part of the free edge at the ends of the slab with a small volume of ABEHGF. When reversing large rolls across the width, which is also prevented, the rolls are formed into a profile-rotates increased stretch and formed end, which reduces the dynamic of the reel in these places during rolling loads during gripping. When rolling the back end (front in the previous pass), the displaceable metal fills a part of the remaining free volume. When the slab is compacted to the required value in several passes, the displaced metal completely fills the free object at the front and rear ends and the bar turns into a rectangular shape in plan, which ensures a reduction in the end cut and a reduction in the expenditure ratio.

Sequential rolling in several vertical stands in one direction. The slb is set to vertical rolls with a profiled end. Due to

that its width CB is B-2a

five

edges on the curvilinear dependence established from the expression (1). The expediency of choosing this expression (1) of parabolic type is explained by the fact that it most closely approximates the experimental data obtained in the simulation of the formation of slab ends to reduce the length of the roll and reduce the expenditure ratio. Structurally, it consists of constant values: B, 2a, 1, and n, as well as variable X. For the same word, characterized by center B, the parameters 2a, 1, and n are variable and are the amount of compression slab

 to the length of the curviline: Yong section along the lateral face from O to 1. At the same time, the length of the curvilinear section along the end face of the slab is selected from the range from - - to § - the total reduction of the tag to

50

width; C 1.5-2.0, d 0.4-0.7). The minimum value of a C-provision in horizontal rolls. The value of C is chosen depending on the shape of the vertical rolls. Thus, the minimum value of C 1.5 is assumed when the slab is reduced in vertical rolls with gauges, when the protrusions on the roll with the dog bone shape move to its center and the broadening during subsequent rolling in horizontal rolls is 30% of the reduction value across the width ba (AB).

to “x slabs), however, its further reduction, 25 may lead to the fact that even with significant deformations along the width of the bar, a defect of the“ tongue ”type is formed. The maximum value of n 3 eliminates the roll at low reductions. With values even with minor shrinking across the width of the effect, no reduction in trimming is observed.

The choice of the optimal boundaries of the parameter. The maximum value of C 2.0 is accepted by the Jurov

the results of statistical processing of the value of the boundary parameters implemented in the laboratory model with a scale of 1:25 decrease when using lead-end subsequent rolling into horizontal samples.

rolls 50% of AV. Laboratory results

are shown in the table.

The efficiency of slab profiling is calculated by the formula

when reducing the slab in vertical rolls with a smooth barrel, when the protrusions on the roll with the “dog bone” shape are located at the edges of the roll and widening

AB

In the course of rolling, in the vertical rolls at the ends of the slab, dog-bone thickenings are formed, which during subsequent rolling in the horizontal rolls are converted into a roll in the form of a fish tail. The maximum value of a d- eliminates the formation of a roll with large reductions in width, when the latter is formed over practically the entire width of the slab. The value of d is determined by the width of the redundant slabs and the capabilities of the profiling devices. The minimum value of d 0.4 corresponds to the maximum width of redu20K. (1 - J-s) X100%, (2)

-and

where K. is the efficiency of slab profiling,%;

Bn is the length of the run-up in the form of a “fish tail on the proposed slab, mm;

Bi is the length of the run-up in the form of a “fish tail on a known slab, mm.

From the data of the table it is seen that when rolling the proposed slabs with all

25

slaves, and the maximum value of the limit values (conditional

numbered 2, 4, 6) the efficiency of slab profiling (reducing the length of rolled products in the form of fish tail) is 3–9% as compared with the known slab (1, 3, and 5). With the introduction of one of the parameters of the curve,

Formation of an overrun defect of the type “tong. The length is close to the average value (n 0.5),

Slab co-profiling efficiency is 25% (8) compared with the known slab (7). With the introduction of two parameters of the curve, close to their mean values, the efficiency of profiling

A d of 0.7 corresponds to the minimum widths of the slabs being reduced. At a

d-S at the ends of the slab, possibly along the curvilinear section 1, on the lateral face of the slab is chosen from 0.5 Id to 31d (Id is the length of the deformation zone when rolled in vertical rolls; Id / R-AB, where R is the radius of vertical

rolls, mm). The minimum value of 1 slab is 33% (10) compared to 0, which ensures the absence of a fish tail at the ends of the slab with a small reduction in width. At 1 0.51d, a fishtail defect is observed at the ends of the slab, even with small deformations in width. The maximum maximum value of 1 31d is chosen because of the fact that a different amount of stretching across the width of rolled slabs is observed already at a distance of 31 d from the end of the slab. Long-known service (9). With the introduction of all the parameters of the curve, close to their mean values, the efficiency of slab profiling reaches 83-85% (12

 c and 14) compared to the known b

 (11 and 13).

As can be seen from the presented experimental data, the use of the proposed profiled layers allows a neck increase that can lead to 50 to reduce the length of the formation, with the fact that even with significant grinding in the vertical rolls of rolls, the width on the rolling will produce 85% . Reducing the length of the rolls allows

cut the length of the trim at the front and rear ends of the roll before his task in the finishing group of the mill. Pruning cut

effect type "language. The exponent n is in the range of 0.25 to 3.0. The minimum value of n 0.25 eliminates

the formation of a reel with a large reduction in x55 by 85% makes it possible to reduce the consumable coefficient with a significant non-uniformity of the metal strain during rolling on SHSGP

on the width of the slab (when rolling from 1.045 to 1.030. Save metal at

in vertical rolls, this is extremely wide, 1.5%. Obtaining a slap code), however, its further reduction, 25, can lead to the fact that even with significant deformations along the width of the bar, a “tong” defect is formed. The maximum value of n 3 eliminates the roll at low reductions. With values even with minor shrinking across the width of the effect, no reduction in trimming is observed.

The choice of the optimal boundaries of the parameters of the proposed slab is confirmed by

20K. (1 - J-s) X100%, (2)

-and

where K. is the efficiency of slab profiling,%;

Bn is the length of the run-up in the form of a “fish tail on the proposed slab, mm;

Bi is the length of the run-up in the form of a “fish tail on a known slab, mm.

From the data of the table it is seen that when rolling the proposed slabs with all

25

 the slab is 33% (10) compared

with a known service (9). With the introduction of all the parameters of the curve, close to their mean values, the efficiency of slab profiling reaches 83-85% (12

 c and 14) compared to the known b

 (11 and 13).

This form of coupling of the side end faces can be made in vertical rolls due to their movement according to a predetermined program, for example, with hydraulic clamping devices, directly in the rolling process of the slab.

The application of the proposed slab reduces the expenditure ratio of the metal by reducing scrap due to the reduction of the fishtail defect.

Claims (1)

Invention Formula Slab for the production of strips, preferably wide, the end faces of which have curvilinear sections in plan, characterized in that, in order to reduce the expenditure ratio of the metal due to the contraction of the cut by decreasing the end-shaped defect 0 five the “fishtail” type, the end faces of the slab are made with straight sections, and the curvilinear sections of the end faces that adjoin their straight lines with side faces are made according to the curve described by the equation y - S - 2a (| -G, where y is the current slab width, changing from y to B - 2a at the slab butt and to y to B on the length / from the butt, mm; B — width of slab, mm; a is the length of the curved section along the end face of slab, mm; X-current coordinate, MMJ / is the length of the curved section along the lateral face of slab, mm; n-exponent (0,, 0). etc Note: Parameter values; - minimal, P - proposed, and - known. - average, maximum. If you would: 2