SU1421441A1 - Rolling mill roll - Google Patents

Abstract

The invention relates to rolling production, in particular to the production of hot rolled sheets. The purpose of the invention is to reduce the transverse rolling thickness variation. The barrel of the roll 1 consists of two cylindrical sections of different diameters mated by a third transition section, the length of which is 0.16-0.33 times the length of the roll barrel, while the end cylindrical sections of the roll are the same length, and their diameters are related by the ratio 1 , 05-1.15, the ratio of the cylindrical end portion to the total length of the roll barrel is 0.33-0.41. The proposed profiling of the cooking makes it possible to reduce the transversal thickening of hot rolled sheets during the rolling of the metadol and, due to this, to increase: THEIR quality. 1 il. 1 tab. .

Description

BUT/

(L

The invention relates to rolling production, in particular to the production of sheets by the method of hot rolling,

The aim of the invention is to reduce the transverse thickness variation of the rolled stock.

The drawing shows the roller unit.

 The assembly includes two working rolls with a barrel length L, between which there is a deformable sheet 2. The rolls have two end cylindrical sections 3 of equal length L, which are conjugated to each other by a transitional conic section 4 of length L.

The rolling of metal in the rolls of the proposed construction is carried out as follows.

During rolling, the metal flow rate in the extreme parts of the strip is higher than the metal flow rate in the transition zone. At the same time, the flow rate of the metal located in the edges of the strip is determined by the height of the diameter D,. The flow rate of MeTaJina in the middle part of the strip is determined by the size of the diameter D, which is smaller than D

Along with such high-speed conditions of metal flow during rolling in the proposed rolls, the metal is expanded in width by the middle conical part of the rolls. The magnitude of this acceleration depends on the ratio of the transitional conical zone of the roll and the size of the rim shafts. Such a complex nature of the metal flow in the deformation zone is the cause of the occurrence of tensile stresses in the metal and its output from the deformation zone, while the magnitude of the tensile stresses is wired to the transverse thickness difference towards its reduction.

Reducing the thickness of the sheet in its middle part during rolling compensates for the increase in hot spot} strip, caused by the elastic deformation of the rolls.

The ratio of the diameters of the Schsinderich: with-kih end sections of the barrel shaft

DI

should be -g

2D,

1.05-1.15.

At ratios 1.05 effect and / 1

The influence of tensile stresses on the transverse thickness variation is negligible.

With

ratios

Da da

1.15

0

five

0

five

0

five

0

0

five

difficulties arise when the strip is gripped by the rollers, especially for thin sheets, and in addition, considerable tensile stresses appear, leading to thinning of the strip in its middle part beyond the tolerable value.

The length of the transition section b can vary within L (0.16-0.33) L, where L is the length of the roll barrel.

At values of L 0.16 L, on average over the width of the strip section, insignificant tensile stresses occur, which do not lead to a change in the cross section of the sheets, i.e., to a decrease in the transverse dissimilarity of HALF.

At values of L 0.33 L, the value of tensile stresses in the central part of the strip is significant, which leads to a decrease in the thickness of the sheet in its middle part over the width above the permissible value.

The ratio of the length of the cylindrical end portion to the total length of the roll barrel is 0.33-0.41. When rolling in rolls, complete with violations of the proposed profiling, which is regulated by the specified ratios of the sizes of sections, there is an increase in the sheet transverse thickness variation: as the L: L ratio is increased, more than 0.41, the sheet transversal thickness difference does not decrease, 33 leads to a strong weft of metal in the center.

The proposed roll design was tested under laboratory conditions. The studies were carried out during the rolling of lead strips with a width of 100 mm and a thickness of 6.50 mm. When rolling under the conditions of specified ratios, / 1. and D / Dj, a decrease in the thickness of the bands in their middle part was obtained. Both the separate influence of factors and D. "/ D, j, and their joint influence on the change in the cross section of lead bands was investigated.

The research results are summarized in the table.

As can be seen from the above results, rolling in the proposed rolls reduces the thickness of the sheet in its middle part by 2.5-9%, which leads to a decrease in thickness

3 U2

  but

sheets taking into account the elastic deformation of the rolls (examples 1-3). Moreover, from the data of the table it can be seen that if the parameters of the rolls exceed the proposed boundary values, a positive effect is not achieved: so, for ratios 0.45 and

(1.03), a decrease in the thickness of the sheet in its middle part (Example 4) is not observed, and at the ratios x. L, / L –0.25

and D, / D 0.18, the sheet thickness is reached by 10% or more, which results in sheets with thinning in the middle part beyond the allowable value.

Thus, the use of the invention in the production of sheets by the way Rolls have parameters beyond the proposed boundary values.

A bom hot rolling minimizes their transverse thickness variation.

Claims (1)

Invention Formula Rolling rolls containing a barrel with two cylindrical sections of different diameters mated to a third transitional conical section, characterized in that, in order to reduce the transverse thickness variation of the rolling stock, the cylindrical roll sections are made of the same length, and their diameters are related in a ratio of 1.05 -1.15, with the ratio of the cylindrical portion to the total length of the barrel being 0.33-0.41.