SU801916A1 - Method of working support roll barrels - Google Patents

Description

one

The invention relates to metallurgy and can be used in the production of rolled products on sheet mills.

It is known that on double-square quarto training mills, for example, mills 1200, during the tempering (rolling with low rolling) of tin without the use of technological lubricant, the surface of the support rolls is polished. The cause of such an occurrence is often the increased temperature of the bands of the trained tin, the insufficient disinfection of their surface. Since the state of the surface across the width of the strips and on the upper and lower sides may be unequal, the upper and lower support rolls of the training mill will be unevenly e-polished.

with

During the subsequent filling into the stand of the work rolls, their surface is also polished during the contacting process with the surface of the support rolls. Different polishing of the upper and lower work rolls leads to uneven stretching of the strip and loss of flatness. As a result, the quality of the trained sheet deteriorates. Therefore, when olor rolls are polished,

their transshipment. In connection with the downtime of a mill, its productivity decreases, and as a result of the subsequent removal of the surface layer, the consumption of rolls per tonne of rolled products increases. After the roll out of the stand, the polished support rolls are machined to give their surface the desired microrelief.

Known methods for mechanically processing the barrels of mill rolls turning them or grinding them l.

5 The disadvantages of these methods are that for machining the rolls need to be thrown out of the cage. This leads to a decrease in the productivity of mills due to loss of time for transshipment. The grinding of the rolls directly in the cage requires complex tooling for this process and has not become widespread.

5 Also known is a method of machining the rolls of rolls in the mill stands by loading them in the process of processing with an expansion force in the roll gap 2.

In this method, in order to increase the machining accuracy, the rollers are bursting with a fixedly mounted template that repeats the shape of the rolled stock, and use the same pattern as a cutting tool, for example, covering its surface with an abrasive sheet. The value of the spacer effort during the processing is maintained equal to the calculated rolling force. The disadvantage of the known method is that it does not allow treating the support rolls of quarto mills, for example, sheet walls, and also that it does not allow a coarse isotropic microrelief to be applied to the surface, which prevents resumption of eapolation. The aim of the invention is to apply an isotropic microrelief on the surface of the drums of the support rolls. The goal is achieved by the fact that the microrelief is applied by rolling back the support rolls with a working tool, which is used as a working surface with a roughness of 2-50 times the initial surface roughness of the rolls of the support rolls. The machining of the surface of the support rolls with the aim of applying a microrelief on their surface is carried out directly in the rolling stand by treating the workers with the pressure of the workers against the roller rolls (spreading force equal to the rolling force. The cage is filled with work rolls with a very rough surface. Between the upper and lower work rolls, gaskets are inserted to prevent the contact of the upper and lower drums. When they are mixed with the help of pressure devices, then with the help of pressure devices, the support rolls are pressed against the workers with a force equal to the rolling force, and the workers start to rotate. backing roller, processes this surface, removing (peeling) the polishing of the surface. As a result, a new microrelief is formed on the surface of the support rolls without any disadvantages, zapolirovat surface of beings. The work rolls used here as a cutting tool for processing the surface of the support rolls must be pressed against the support rolls with a force equal to the rolling force, because, in this case, the support rolls along with the necessary .. surface microrelief will also acquire the required profile ( convexity, concavity, etc.). After the surface of the support rolls has been processed, the work rolls that have been used as a cutting tool are removed from the cage, and the work rolls are overfilled with the surface finish required from the standpoint of quality of the trained sheet. The required roughness of the work rolls used to treat the surface of the support rolls is preselected. As a rule, the roughness of the work rolls used as a cutting tool should be 2-50 times greater than the roughness of the polished surface of the rolls of the support rolls. Specified limits; The ratios of the surface roughness of the drums of the rolls used as a cutting tool to the roughness of the drums of the machined support rolls were chosen on the basis of the following considerations. When polishing, the surface roughness of the support rolls may be as low as 0.2 µm Ro (10th grade of purity according to GOST 2789-73). For machining the support rolls, it is advisable to use work rolls with a notched shot of the surface. In this case, the notched surface of the rolls may have a roughness of up to 100 µm Ra. Higher surface roughness on existing shot-blast rolls | difficult to obtain, and it is not required. Thus, the maximum ratio of the roughness values of the work roll barrels to the initial roughness of the support roll barrels is 50. If we take the ratio of the minimum surface roughness of the work rolls obtained after their shot blasting notch to the maximum roughness value the polished surface of the support rolls of approximately 1.0-1.2 MKMlia / TO, another extreme value for the ratio range is 2. Therefore, the limits of this ratio will be 2-50. In each particular case, the value of this ratio should be chosen differently depending on the quality requirements for processing the support rolls, but it will be in the specified range. The rotation of the work rolls during processing of the support rolls must be performed at the speeds used in the strip rolling process at this mill. The processing time is determined by the quality requirements of the surface to be treated. As a rule, it should be several minutes.

Claims (1)

Claim 35 The method of machining the rolls of the backup roll barrels by applying a microrelief to their surface with a working tool when loading the rolls with an expansion force of up to, characterized in that, in order to apply the isotropic microrelief of the rolls of the supporting rolls to the surface, the microrelief is applied by rolling the backup rolls with a working tool, as which * 5 work rolls are used with a roughness previously applied to them equal to 2-50 values of the initial surface roughness of the roll roll barrels.