SU1258521A1 - Method of reversing rolling of strip - Google Patents

Abstract

The invention relates to the field of rolling production and can be used to increase the durability of the support rolls during the reversible rolling of hot strips in the quarter cells. The purpose of the invention is to increase the yield; due to uniform wear of the work rolls. The method consists in that the rolling is carried out with alternate displacement of the strip relative to the axis of rolling by the value a, defined by the expression o1 (b)) / / (h-) 3, where в is the width of the working roll barrel; B is the width of the strip; n is the number of passes in the (reverse) direction; (- the number of the pass of the strip in the direct reverse direction), i - 1,2, ..., h; K - coefficient k 4 - 8. 8 cl. L

Description

The invention relates to rolling production and can be used to increase the stability of the support rolls. In the reversal rolling of hot strips in quarto cells.

The purpose of the invention is to increase the yield due to uniform wear of the work rolls.

FIG. Figure 1 shows the distribution of the multi-roll pressure over the contact length of the working and support rolls of the quarto stand during rolling of the strip along the rolling axis; in fig. 2 shows the distribution of the inter-roll pressure during the rolling of strips with a gradually decreasing width, FIG. 3-7 - formation of generation on the barrel of the work roll when rolling the strip with alternate displacement relative to the axis of the rolling stand; on e1) ig. 8 shows the distribution of the inter-roll pressure over the length of the contact between the working and support rolls, which occurs in this case.

When rolling strips 1 of width D in work rolls 2, in the middle part of their barrels, generation 3 is formed. The torus creates an uneven distribution of the inter-roll pressure at the contact of the working and support 4 rolls, described by the CL curve. At the same time, the maximum inter-roll pressure

,% .. (1.5 - 2.5) h ;,

where C} is the average pressure along the contact length between the working and support rolls.

Under the action of maximum pressure, in sections I and II of the barrel of the support roll 4, contact destruction of its surface layers occurs, which causes low resistance of the support rolls.

When rolling strip 1, the width of which is uniformly reduced from the value to jtvow. , the production of 3 work rolls 2 has the shape of a trapezoid. The uneven pressure distribution in the barrel of the support roll 4 is described by a curve $. In this case, the presence of transition sections on the barrel of the work roll reduces the maximum inter-roll pressure.

W 3-2 0) C which slightly increases durability

support rolls.

2585212

The efficiency of the quotation p depends on the technological parameters of the rolling process and the design characteristics of the rolling stand and is determined by the stiffness and strength of the bearing units of the roll system, the maximum rolling force, the degree of accuracy of the geometric dimensions of the strips, etc. For example, for the roughing stand of 10 sheet mill 3600 when rolling

. blanks for a sheet with a cross section of 8.0 x 2000 mm after breaking its width, the value of K, and when rolling the blank

15 for a sheet of 8.0 x 2500 mm, the value of K 6.5.

Let us consider the formation of an output along the length of the roll barrel in the event of an alternate displacement of the strip from the rolling axis 20 ki in opposite guides by

a.V (1..1L),. to h-1

with v 4 and p 3,

In the first forward pass, the strip 1 (Fig. Zy.) Is shifted, for example, to the left from the rolling axis

° hb-b

(, 3-1 /

At the same time, production 2 is formed on the barrel of work roll 2. In the first reverse pass, strip 1 is shifted to the right from the rolling axis by

At the same time, production 3 is formed on the barrel of the work roll 2.

In the second forward pass, the strip 1 is shifted to the left from the rolling axis by the amount of

.6-b,. 2-1

(one ".

2-)

8-b

and on the barrel of the work roll 2, generation 3 is formed.

In the second reverse pass, the strip 1 is shifted to the right from the axis of the rolling stand to the distance

And on the barrel of the work roll 2, generation 3 is formed.

In the last third forward pass, the strip 1 is directed into the gap between the work rolls 2 on the rolling axis, since

(1 3-1

 zt

-) about

and a development 3 is formed on the barrel of the work roll 2.

Thus, with repeated reversible rolling of the strips with their pd-: by another displacement from the axis of the rolling stand to the opposite in the direction of the indicated relation, the processing 3 is formed on the barrel of each work roll 2, which is characterized by an increased length t of transition sections. With this form of production of work rolls, the non-uniform distribution of roll-over pressure, both with symmetric and asymmetrical rolling of strips, is significantly less than with reverse rolling of strips by known methods.

I (1.2-1.5).,.

WK

The proposed method of reversible rolling strip provides higher

Claims (1)

improvement of the stability of the support rolls by 20–30%, as well as an increase in the yield of 1.0–1.5% fit due to a reduction in the planned downtime of the mill, associated with roll handling. Invention Formula The method of reversible rolling of the strip in the quarto stand, including sequential multiple rolling, characterized in that, in order to increase the yield due to uniform wear of the work rolls, rolling is carried out with alternate displacement of the strip relative to the axis of rolling by the amount Ct, determined by the expression Q Alb. -. (1 -III. ) where 8 is the width of the barrel of the work roll; b is the width of the strip; h is the number of band skips in the forward (reverse) direction; 1 - number of the pass of a strip to the right of mine (backward direction), 1 1,2, ... Y); K - coefficient (K A-8). .Z