Long-acting protective coating for furnace wall of gas nitriding furnace and preparation method thereof

Abstract

The invention provides a long-acting protective coating for a furnace wall of a gas nitriding furnace and a preparation method thereof. The protective coating comprises an adhesive, silicon dioxide, boric anhydride, calcium oxide, copper oxide and sylvite, and preferably further comprises an anti-seepage agent. The melting point of a glass coating is adjusted, so that the coating is of a glass molten state structure at high temperature and has good viscosity and sealing effects, the coating is converted into solid glass after being cooled to the normal temperature, and the coating can keep a complete structure under temperature difference impact. The coating also contains functional elements such as boron, silicon, copper and potassium, the physical and chemical properties of a coating layer can be improved, and the coating has a good application prospect.

Description

technical field [0001] The invention relates to the field of material science and technology, in particular to a long-term protection coating for a gas nitriding furnace wall and a preparation method thereof. Background technique [0002] Metals are easily oxidized at high temperatures. In order to overcome this problem, coatings are usually used to protect the surface of metal materials. The conventional coating structure has poor bonding ability with the metal itself, and after many times of thermal expansion and contraction, The adhesion between the coating and the metal layer decreases, and even cracks or peeling may occur. To overcome this problem, a high-temperature resistant layer can also be compounded on the surface of the metal. [0003] However, in the field of metal processing, the nitriding furnace will not only repeatedly experience high temperatures, but also be filled with gas containing nitrogen elements, so the inner wall of the furnace will also be repeate...

AI Technical Summary

Problems solved by technology

[0002] Metals are easily oxidized at high temperatures. In order to overcome this problem, coatings are usually used to protect the surface of metal materials. The conventional coating structure has poor bonding ability with the metal itself, and after many times of thermal expansion and contraction, The adhesion between the coating and the metal layer decreases, and even cracks or peeling may occur. To overcome this problem, a high-temperature resistant layer can also be compounded on the surface of the metal

[0003] However, in the field of metal processing, the nitriding furnace will not only repeatedly experience high temperatures, but also be filled with gas containing nitrogen elements, so the inner wall of the furnace will also be repeatedly covered with nitrogen elements during the nitriding process, resulting in excessive nitriding. The high temperature resistant metal layer is used, and the over-nitrided furnace is easy to crack and be scrapped. Therefore, it is an urgent technical problem to provide a long-term protective coating for the nitriding furnace wall with anti-nitridation and high temperature resistance.

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