Method for preparing anticorrosive paint and coating thereof

Abstract

The invention discloses a method for preparing anticorrosive paint and a coating thereof. The method comprises the following steps: preparing a base material and filling slurry, and mixing the base material with the filling slurry in a weight ratio of 1:1-1:4; and uniformly stirring to prepare the paint. The coating is constructed by spraying, brushing, rolling and other processes, and the constructed part can be cured at the temperature of 150-200 DEG C, and a completely compact imporous coating can be formed after secondary heat treatment at high temperature of over 600 DEG C.

Description

technical field [0001] The present invention relates to the technical field of chemistry, in particular to the technical field of coatings, in particular to an anti-corrosion coating for an engine exhaust system and a preparation method thereof. Background technique [0002] The exhaust system of a diesel or natural gas engine is constantly subjected to temperature changes between high temperatures up to 800°C and low temperatures down to minus 40°C. The front end of the exhaust system includes components such as the exhaust manifold and the exhaust pipe of the supercharger, which are generally made of ductile iron. These iron parts are exposed to different temperatures and environments, and are easily attacked by corrosive gases in the air, such as chloride ions, carbonate ions, and NOx, and are easily oxidized and corroded to cause rust. The corroded exhaust system will reduce the service life, and the rust on the surface will also peel off and spread, affecting the life ...

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Problems solved by technology

Chinese patent application CN102140308 discloses "a new type of high temperature resistant coating", which is a silicone resin high temperature resistant coating with aluminum powder as the main filler. The main components of this coating are methyl or phenyl silicone resin, metal aluminum powder The addition of the coating increases the use temperature, and it performs well below 500°C, but at higher temperatures, the silicone resin is prone to thermal cracking, and the metal aluminum will also undergo oxidation reactions. This kind of coating cannot be used at high temperatures above 600°C. Play a long-term anti-corrosion effect, can not meet the anti-corrosion of the engine exhaust system

There is another inorganic high-temperature coating with a heat resistance above 1000°C (Modern Technical Ceramics, 2011, p. 39), which contains rare earth oxides, but its thermal expansion coefficient does not match the engine material, so it cannot withstand drastic changes in cold and heat, and cannot be used in cold and hot conditions. In the anti-corrosion of the engine exhaust system that changes drastically, it is very easy to crack and fall off during the drastic changes in cold and heat

Some other high-temperature-resistant coatings based on inorganic materials such as sodium silicate and aluminum dihydrogen phosphate, because the coating is not dense and contains pores, cannot prevent the penetration of corrosive gases or liquids, and still cannot be used for anti-corrosion in the exhaust system of the engine.

As a traditional anti-corrosion technology, glass-lined technology is mainly made of glassy materials, which can form a dense coating on the surface of the metal, which can withstand a certain temperature, but its thermal shock resistance is very poor, and it cannot be used for repeated cooling. Thermal cycle engine exhaust system

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