Acid-corrosion-resistant enamel coating layer on surface of weather-resistant structural steel and preparation method of acid-corrosion-resistant enamel coating layer

Abstract

The invention discloses an acid-corrosion-resistant enamel coating layer on the surface of weather-resistant structural steel and a preparation method of the acid-corrosion-resistant enamel coating layer. The preparation method of the acid-corrosion-resistant enamel coating layer on the surface of the weather-resistant structural steel comprises the steps: a) melting enamel glazes, b) preparing enamel glaze powder, c) performing alkaline degreasing treatment on the weather-resistant structural steel, and d) performing spraying and high-temperature firing on the enamel coating layer, wherein the enamel glazes comprise two kinds, namely an enamel enamel A and an enamel enamel B. The acid-corrosion-resistant enamel coating layer on the surface of the weather-resistant structural steel, whichis obtained by adopting the preparation method disclosed by the invention, has the advantages of excellent acid corrosion resistance, particularly sulfuric acid corrosion resistance, high bonding strength, long service life and the like. In addition, the preparation method is simple, the two glazes are adopted for separate melting, the surface of the weather-resistant structural steel is subjectedto alkaline degreasing treatment, the production efficiency is improved, energy consumption is reduced, the production cost of the enamel coating layer is reduced, and the preparation method is suitable for large-scale application and popularization.

Description

technical field [0001] The invention belongs to the field of inorganic protective coatings, in particular to an acid-corrosion-resistant enamel coating on the surface of weather-resistant structural steel and a preparation method thereof. Background technique [0002] Weather-resistant structural steel is to add a small amount of alloying elements, such as Cu, P, Cr, Ni and rare earth elements, to the steel to form a protective layer on the surface of the metal substrate, thereby improving the weather resistance of the steel plate. However, when weathering structural steel is used in a corrosive environment, such as heat exchange elements in desulfurization and denitrification heat exchangers, due to the poor sulfuric acid corrosion resistance of weathering structural steel, especially in desulfurization and denitrification heat exchangers, when the local temperature reaches At the dew point of sulfuric acid, the weather-resistant structural steel is easily corroded, resul...

AI Technical Summary

Problems solved by technology

However, due to the excessive low melting point components (such as zinc oxide, sodium oxide, etc.) contained in ordinary enamel coatings as co-solvents, the low melting point components are easy to react with Cr in the alloy matrix during high temperature service. , and finally further oxidized on the surface of the coating to generate a large amount of chromate spinel corrosion products, such as ZnCr2O4, which greatly reduces the oxidation resistance of the enamel coating, and the addition of a large number of low melting point components breaks the silicon-oxygen tetrahedron The silicon-oxygen bond in the enamel makes it easier for the alloy ions in the corrosive medium to penetrate into the enamel coating, thereby further reducing the softening point of the enamel coating, making it easier for sulfur and chloride ions to penetrate through the enamel coating to the alloy matrix, seriously Affects the corrosion resistance of enamel coatings