SU954131A1 - Method of cleaning metallic strip surfaces from scale - Google Patents

Description

one

The invention relates to sheet-rolling production, in particular to the cleaning of metal strips from scale.

A known method of cleaning the surface of strips from scale, including etching a strip in acid solutions with a mechanical breakdown of the scale, preceding it by repeated bending of the strip, stretching, tempering, etc. At the same time, cracks formed during the destruction of the scale penetrates the acid, which reacts with the main metal goes with the formation of hydrogen, cracking a layer of scale, which provides access and further flow to the metal of the pickling solution.

However, the known method of the mechanical destruction of the scale layer does not ensure high performance and quality of strip etching, since the external hematite layer of scale has high strength.

and under the action of stresses only squeezing And stretching in places, and is not destroyed. As a result, undertravels remain on the strip, and with an increase in the time of etching, the productivity of the process decreases and overgrass regions are formed.

The purpose of the invention is to increase the productivity and quality of etching of the strip.

"about

This goal is achieved by the fact that during the implementation of the method of cleaning the strip from scale, which includes the preliminary mechanical destruction of the layer of scale and the subsequent 5 etching of the strip, the said mechanical destruction of the layer of scale includes the application of scratches to the surfaces of the strip.

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Claims (2)

Scratches on the surface of the strip are applied by pulling it through a layer of abrasive powder, compacted under pressure "O-kgf / cm. In this case, the scratches may be shallow, since the purpose of scratching is to destroy only a thin layer of hematite (magnetite and wustite are destroyed during repeated bending on the descaler). Scratches on the surface of the strip can be applied by any mechanical means, metal brushes, compacted abrasive powders through mechanical means, or by an electromagnetic method. Much less pressure is needed to scratch a strip than to completely destroy and remove scale, therefore, the strip abrasive machine in this application is much simpler and more economical than installations to completely descale the abrasive powder. To scratch the surface covered with dross, it is sufficient to compact the abrasive powder with a pressure of ~ 40 kg / cm, since the experiment showed that with such a pressure, an increase in the etching rate is 1 times. An example. A roll of hot rolled sheet is unwound on the unwinding of the body of the continuous-etching unit and fed to the descaler, ate on the paired pulling rollers and roller straightening machine, where the crumpers are mechanically cracked, then cut off the ends of the strip and cook the front end of the roll with the rear end of the previous roll. The strip is sent to a dressing stand, after which it is pulled through a set with compacted abrasive powder, after which the strip is fed to pickling baths. Claim 1. Technique for cleaning the surface of metal strips from scale, including preliminary mechanical destruction of the layer of scale and subsequent etching of the strip, characterized in that, in order to improve the performance and quality of the etching of the strip, the said mechanical destruction of the layer of scale involves scratching the surfaces of the strip . 2. A method according to claim 1, characterized in that scratches are applied to the surface of the strip by drawing it through a layer of abrasive powder compacted under a pressure of kgf / cm. Sources of information taken into account during the examination 1. V.Fainshtein. Improving the process of cleaning the bands from the eyes abroad. M., Objorn information, ser. 7, issue. 2, Chermetinformatsi, p. five.