Graphite Crucible, because of its high temperature resistance, small thermal expansion coefficient, against thermal shock has a certain resistance to strain performance, acid, alkaline solution of strong corrosion resistance, with excellent chemical corrosion stability, so in the metallurgical, foundry, mechanical, chemical and other industrial sectors, is widely used in alloy tool steel smelting and non-ferrous metals and alloys smelting, and has a better technical and economic results.
Graphite crucible is mainly made of graphite, which is a allotrope of carbon, each of which is connected with three other carbon atoms (arranged in a honeycomb-shaped plurality of hexagonal) to covalent bonding. Graphite Crucible is mostly carbon, part of the air, so that graphite crucible at high temperature prone to oxidation, Shu, shedding and other phenomena. A new antioxidant coating researchers found that graphite material began to oxidize at about 500 ℃, and the oxidation rate increased with the increase of graphite crucible temperature, and the oxidation increased.
The graphite materials synthesized at high temperature include graphite electrode, graphite mould and graphite crucible three, the graphite in three kinds of materials at high temperature, the graphite is easily oxidized and combustion reaction, resulting in the increase of the porosity of the surface layer of the material and the loose structure, which affects the service life. For example, the normal baking of ladle, carbon (graphite) refractory is produced after baking on the general surface of 15mm above the decarburization layer, decarburization layer in the steel soon after the erosion. At this time most graphite crucible using high-temperature sealing coating, this coating temperature high temperature, the use of special high-temperature solution, temperature can reach 1800 ℃, can be long time to withstand fire barbecue, coating materials using nano-scale flake structure, dense, effective to prevent oxygen at high temperature diffusion, hardness can reach 7-8h, hardness higher than the hardness of metal.
High temperature sealing paint coating on the graphite crucible to form a dense coating, with a strong anti-rust anti-corrosion, High-temperature anti-oxidation, anti-discoloration, wear-resistant characteristics. High temperature sealing coating in kiln, graphite, metal, etc., to prevent high temperature oxidation rate can reach more than 80%, graphite crucible material energy-saving efficiency can reach more than 95%.
And in the special high temperature induction heating graphite crucible graphite block, the high-temperature oxidation of the graphite electrode used in the environment due to the high temperature arc will be part of the sublimation oxidation, will lead to the continuous consumption of graphite crucible, and even break, damage. The loss rate of graphite crucible will reach $number. The new High-temperature sealing coating is mainly used to protect the graphite electrode, graphite crucible and graphite parts in high-temperature environment, delay the oxidation speed, increase the strength of materials and improve the service life. The probability of rupture, breakage and loss of graphite electrode is lower.
After impregnating and brushing the graphite crucible, the high-temperature ZS-1011 graphite transition coating liquid can penetrate into the pores of the graphite crucible, emptying the residual air in the graphite crucible, and forming an antioxidant protective film on the surface of the graphite crucible and the pores of the graphite crucible. It is this layer of protective film can effectively isolate the air directly with the graphite crucible contact with the oxidation reaction, by the antioxidant coating impregnation treatment of graphite crucible, will not be in the high temperature change cracking, shedding, thus effectively delaying the oxidation of graphite crucible, prolong the service life of graphite crucible.
Graphite Crucible Antioxidant coatings, water-based inorganic Environmental Protection coatings, high-temperature, room temperature without any volatile substances produced. High temperature sealing coating itself acid and alkali resistance, but also do not react to quenching medium, can effectively protect the graphite crucible at high temperature chemical reaction, can effectively prevent graphite crucible at high temperature oxidation rate of more than 95%.