SU1397476A1 - Lubricating coating for molten-metal rolling - Google Patents

Abstract

This invention relates to lubricating coatings for the liquid rolling of metals. The goal is to prevent metal from sticking to the rolls and to improve the quality of the metal surface. The lubricant contains, in wt.%: Graphite 25-35J aerosil, modified with dichlorosilane or methyl chlorosilane, 3-7; kaolin 4-8; brown coal wax to 100. The introduction of aerosil, possessing a hydrophobic effect, provides a reliable high-temperature shielding film. Graphite improves the antifriction properties of the lubricant when the liquid metal contacts the surface of the rolls. 2 tab. about s

Description

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The invention relates to metallurgical production, namely, technological lubricants for metal forming, and can be used for liquid cutting.

The purpose of the invention is to prevent metal from sticking to the rolls and to improve the quality of the treated surface. For the preparation of a lubricant using | K) T coal wax, graphite, kaolin, aerosil, modified dimethyldi, chlorosilane or methyl chlorosilane and

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The metal on the rolls is prevented: it is rotated due to the introduction of aerosil into the lubricant, which, when in contact with the heated metal, has an intumescent effect, since the aerospp at high temperature, in contact with

 moisture vapor contained in talc and kalinin, having a hydrophobic effect, forms a reliable high-temperature shielding film. To improve the antifriction properties at the contact of the liquid metal with the surface of the rolls, graphite is used, and as a binder, brown coal wax and kaolin are used to create a given ag, regatta state and provide the required mechanical properties of the lubricant coating.

I Brown coal wax is contained in the i lubricant in an amount of 30-50 wt.%. This component is a binder. i When its content is less than 30% by weight, the lubricant briquettes have low mechanical strength and are scattered when used. The upper limit of the i content of the binder component is necessary to take 50 wt.%, Since a further increase in the amount of wax leads to a decrease in the lubricity efficiency (|) due to a decrease in the content of air Grafit added to the lubricant in an amount of 25-35 wt. % to improve the antifriction properties of the lubricant at the contact of the liquid metal with the rollers. A graphite content of more than 35 wt.% Results in contamination of the surface of the metal being squeezed, and less than 25 wt.% Reduces the anti-friction properties of the lubricating coating.

Used Aerosil 3-7 May.% Allows you to create on the surface of the metal reliable temperature and temperature

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shielding film preventing it from sticking to the rolls.

When the content of aerosil is less than 3 wt.%, The protective properties of the coating are lost and the likelihood of metal adhering to the rolls occurs. An increase in the content of aerosil (7% by weight) is uneconomical, no further improvement in properties is observed.

In the composition of the lubricant, talc is contained in the amount of 6-10 wt.% And contributes to the creation of a reliable high-temperature film. A talc content of less than 6 May .7 results in a weakening of the film coating. When the content of talc is more than 10 wt.%, The physical properties of the lubricant deteriorate, the briquette becomes brittle.

When the content of kaolin is more than 8 wt.%, The briquette loses its elasticity and becomes brittle. Its content is less than 4 wt.% Leads to a decrease in the melting point of the briquette, the briquette becomes viscous, which leads to deterioration of the properties of the lubricating coating.

The compositions of lubricants are given in table.1.

The proposed coating is made by melting the brown wax at 80-90 ° C and introducing into it successively all the components of the lubricant in the required amount with mechanical stirring. This mixture is then poured into a specific shape, where it cools for some time during cooling. In this way, a solid lubricating coating of a predetermined shape (circular, square or rectangular cross section and the required length) is obtained, which is mounted on the working surface of the rolls with the help of a simple device.

Upon contact with the rolls, the lubricating coating is applied with a thin, uniform layer on the rolls, with further falling into the deformation zone, it prevents the metal from sticking to the rolls and is a method of obtaining rolled products with high surface quality.

Laboratory tests are carried out on the proposed lubricating coating.

A metal crucible with zinc granules is placed in a shaft-type electric furnace. After melting, the temperature of the zinc melt is kept constant. Metal sample with SMA applied to its surface

With a zinc coating they dip into the zinc melt. Before the test, the sample surface is cleaned and degreased. The residence time of the sample in the zinc melt varies. Using a stopwatch, fix the time until the zinc adheres to the steel sample, as well as visually monitor the quality of the sample surface.

Briquette of lubricating coating of composition 1 has low mechanical strength and is prone to destruction. Lubrication of the steel specimen is poorly applied and sticking occurs over 3 days in a liquid zinc bath. At the time of the sample being dipped into the zinc melt, no flash is observed. When the sample is degreased after the test, traces of a lubricating coating are noticed on the surface of the tampon.

Composition briquette 2 has higher mechanical properties than composition 1. Lubrication of the sample is easy. Zinc deposits take 16 seconds. At the time of the perch notice a weak flash. When degreasing on a tampon, the remainder of the lubricant coating increases

with .

Briquette composition 3 resistant to destruction, has a high adhesion to the sample. Sticking occurs only after 26 seconds, in which the sample is melted, zinc. At the moment of dipping, the same flash is noticed as in the experiment with composition 2. When degreasing after the experiment, many lubricating coatings remain on the tampon.

The test results of sample 4 are similar to sample 3, but zinc sticking occurs after 25 seconds of the sample in the zinc melt. Duration

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dipping flashes increase and smoke appears.

The test parameters of sample 5 are the same as in the experiment with composition 4. The sticking occurs 10 seconds after the start of the tests.

When testing a known lubricant, the iron sulfate that is part of the lubricant at high temperature decomposes with the release of sulfur compounds that contaminate the surface with harmful impurities containing sulfur. Zinc on the sample takes 20 seconds.

The physicomechanical characteristics of the lubricating coating are given in table 2.

As can be seen from Table 2, the proposed lubricant compositions, during the rolling process, are able to prevent the liquid metal from sticking to the rolls and ensure high surface quality.

Claims (1)

Invention Formula A lubricating coating for the liquid rolling of metals containing Bock coal and graphite, which is so that, in order to prevent metal from sticking to the rolls and improving the quality of the machined surface, the coating additionally contains aerosil, modified dimethyl dichlorosilane or methyl chloro-cjtnaHOM, talc and kaolin in the following ratio, wt.%: 0 Graphite Aerosil, modified dimethyldichlorosilane or methyl chlorine silane Talc Kaolin Brown wax T 25-35 3-7 6-10 4-8 The rest is blitz J Brown wax Rest 13974766 Table 2 Time to sticking zinc | on the sample, s31626251010 I Presence of grease- JHoro coating iHa sampleNon-Minor-Minor-Minor-Minor-Minor