Study and analysis of oxidation resistance coating on graphite crucible

Study and analysis of oxidation resistance coating on graphite crucible

Graphite crucible, because of its high temperature resistance, small thermal expansion coefficient, thermal shock strain resistance, acid and alkali solution corrosion resistance, excellent chemical corrosion stability, is widely used in metallurgy, casting, machinery, chemical industry and other industrial sectors, alloy tool steel smelting and non-ferrous metals and their alloys melting. And has a better technical and economic effect.

The graphite crucible is mainly processed from graphite, that is, an allotrope of carbon, where each carbon atom is surrounded by another three carbon atoms (arranged in a honeycomb pattern of multiple hexagons) to form covalent bonds and form covalent molecules. Most of the graphite crucible is carbon, part is air, so that the graphite crucible is prone to oxidation, softening, falling off and other phenomena at high temperatures.

Graphite materials high temperature synthetic materials include graphite electrode, graphite mold and graphite crucible three kinds. The graphite in these three materials is easy to oxidize and burn at high temperatures, resulting in increased porosity of the rubber layer on the surface of the material and loose structure, which affects the service life. Taking the conventional baking of ladle as an example, carbon-containing (graphite) refractory baking generally produces a decarbonized loose layer of more than 15mm on the surface, and the decarbonized layer is quickly eroded away after filling the steel. At this time, most of the graphite crucible uses ZS-1021 high-temperature sealing paint, which has high temperature resistance. The use of Zhisheng Weihua special high temperature solution, the temperature can reach 1800℃, can resist open flame for a long time. The coating material adopts nanometer fish scale structure, has good densification, can effectively prevent oxygen diffusion at high temperature, and the hardness can reach 7-8H. Harder than metal. Zhisheng Weihua ZS-1021 high temperature sealing coating is coated on the graphite crucible to form a dense coating, with strong rust and corrosion prevention, high temperature resistance, oxidation resistance, resistance to discoloration, wear resistance and other characteristics. The furnace body, graphite, metal, etc. are coated with high temperature sealing coating to prevent high temperature oxidation rate of more than 80%, and the energy-saving utilization rate of graphite crucible materials can reach more than 95%.

In the extremely high temperature induction heating of the graphite crucible, the graphite electrode used in the high temperature oxidation environment will partially sublimate and oxidize due to high temperature arc, resulting in continuous consumption of the graphite crucible and even fracture damage. The loss rate of graphite crucible will reach 40-60%. Years of research and production of ZS high temperature resistant sealing coating is mainly used in high temperature environment of graphite electrodes, graphite crucible, graphite parts anti-oxidation protection, delay the oxidation rate, increase the strength of the material, improve the service life. The probability of breakage, breakage and falling off of graphite electrode is effectively reduced.

After the graphite crucible impregnated with anti-oxidation coating, the high-temperature ZS-1011 graphite transition coating liquid can penetrate into the pores of the graphite crucible, empty the residual air in the graphite crucible, and form a layer of anti-oxidation protective film on the pores of the graphite crucible and the surface of the graphite crucible. It is this protective film that can effectively isolate the air that is in direct contact with the graphite crucible and the oxidation reaction occurs. The graphite crucible impregnated by the anti-oxidation coating of Zhisheng Weihua will not crack and fall off under the change of high temperature, thus effectively delaying the oxidation of the graphite crucible and prolonging the service life of the graphite crucible.

Graphite crucible anti-oxidation coating, water-based inorganic environmental protection coating, high temperature resistance, room temperature without any volatile substances. ZS-1021 high temperature sealing coating itself is acid and alkali resistant, does not react with the quenching medium, can effectively protect the biochemical reaction of the graphite crucible at high temperature, and can effectively prevent the oxidation rate of the graphite crucible from reaching more than 95% at high temperature.