Oxidation resistance treatment of graphite crucible

 

Because of its high temperature resistance, graphite crucible. It has small thermal expansion coefficient, certain strain resistance against thermal shock, strong corrosion resistance to acid and alkaline solutions and excellent chemical corrosion resistance stability. Therefore, it is widely used in the smelting of alloy tool steel and the smelting of colored metals and their alloys in metallurgy, casting, machinery, chemical industry and other industrial departments, and has good technical and economic effects.

 

That is, an allotrope of carbon. The graphite crucible is mainly made of graphite. The periphery of each carbon atom is connected with three other carbon atoms (multiple hexagon arranged in a honeycomb) to form covalent molecules by covalent bonds. Most of the graphite crucible is carbon and some is air, so that the graphite crucible is prone to oxidation, relaxation and falling off at high temperature. The researchers of a new antioxidant coating temporarily found that the graphite began to oxidize at about 500 ℃. With the increase of the temperature of the graphite crucible, the oxidation rate showed a geometric growth and the oxidation intensified.

 

The graphite in these three materials is at high temperature. The synthetic data of graphite at high temperature include graphite electrode, graphite mold and graphite crucible. Graphite is prone to oxidation and combustion reaction, resulting in increased porosity and loose structure of rubber carbon layer on the surface of data, affecting the service life. Taking the conventional baking of ladle as an example, after baking, the carbon (graphite) refractory material generally has a decarburization loose layer of more than 15mm on the surface, and the decarburization layer erodes away quickly after steel is filled. At this time, most graphite crucibles adopt high-temperature resistant sealing coating. This coating has high temperature resistance. It adopts special high-temperature solution. The temperature resistance can reach 1800 ℃ and can withstand open fire barbecue for a long time. The coating material adopts nano fish scale structure with good compactness, which can effectively prevent the diffusion of oxygen at high temperature. The hardness can reach 7-8h, which is higher than the hardness of metal.

 

It has strong functions of rust and corrosion prevention, high temperature resistance, oxidation resistance and discoloration prevention. The high temperature resistant sealing coating is brushed on the graphite crucible to form a dense coating. Wear resistance and other characteristics. High temperature resistant sealing coating is applied to kiln, graphite, metal, etc. to prevent oxidation at high temperature, the oxidation rate can reach more than 802, and the energy-saving utilization rate of graphite crucible data can reach more than 957.

 

The graphite electrode used in high-temperature oxidation environment will undergo local sublimation oxidation due to high-temperature arc, and the graphite crucible heated by induction at ultra-high temperature. It will cause the consumption of graphite crucible from time to time, and even fracture and damage. The loss rate of graphite crucible will reach 40-600. The new high temperature resistant sealing coating is mainly used for anti-oxidation protection of graphite electrode, graphite crucible and graphite parts under high temperature environment, delaying oxidation speed, increasing data strength and improving service life. It effectively reduces the probability of fracture, damage and falling off of graphite electrode.

 

The high-temperature zs-1011 graphite transition coating liquid can penetrate into the pores of the graphite crucible. The graphite crucible is impregnated and brushed with antioxidant coating. Empty the residual air in the graphite crucible, and a layer of antioxidant maintenance film is formed on the pores of the graphite crucible and the surface of the graphite crucible. It is this maintenance film that can effectively isolate the air and directly contact with the graphite crucible to produce oxidation reaction. The graphite crucible impregnated with the antioxidant coating will not crack and fall off in the great change of high temperature, so it can effectively delay the oxidation of the graphite crucible and prolong the service life of the graphite crucible.

 

Waterborne inorganic environmental protection coating, graphite crucible antioxidant coating. No volatile matter occurs at high temperature and normal temperature. The high temperature resistant sealing coating itself is acid and alkali resistant, and also has any reaction with the quenching medium, which can effectively maintain the chemical reaction of the graphite crucible at high temperature and effectively prevent the oxidation rate of the graphite crucible from reaching more than 955 at high temperature.