Graphite electrode antioxidant introduction:
The graphite electrode antioxidant is a pale white or colorless near-transparent liquid formed by dispersing nano-sized ceramic particles in an aqueous solvent. The liquid penetrates into the pores of the graphite material to form a thin layer of high temperature resistant protective film on the pores and the surface of the graphite substrate. This protective film prevents the air from coming into direct contact with the graphite material to cause an oxidation reaction. Moreover, the conductivity of the graphite material is not affected, and the film formed in the surface layer of the graphite substrate and the pores does not crack or peel off.
The graphite electrode antioxidant has inorganic water-based environmental protection, does not react with the quenching medium, can effectively protect the material from chemical reaction oxidation at high temperature, and can effectively prevent the graphite electrode, graphite crucible, graphite rod and the like to prolong the life of the graphite product by at least 30%. That is, under the conditions of electric arc furnace steelmaking, it should have high temperature resistance to ensure other performance requirements at high temperature. The aluminum-aluminum antioxidant has good bonding strength with graphite, is resistant to thermal shock, is not easy to fall off, is transparent and non-stick, has high smoothness, smooth coating surface, electrical insulation, convenient construction, and saves paint. It can fully meet the requirements of graphite oxidation prevention and effectively prevent graphite metal. The high temperature oxidation rate is over 95%, and it can also repair the defects in the color of the graphite after being corroded.
The anti-oxidation graphite electrode refers to a graphite electrode coated with an anti-oxidation protective layer (graphite electrode antioxidant). Forming a protective layer that is both conductive and resistant to high temperature oxidation, reduces electrode consumption during steelmaking (19% to 50%), extends electrode life (22% to 60%), and reduces electrode power consumption. It can also isolate the erosion of oxygen and other corrosive gases, and also has a certain mutual penetration with the substrate to enhance the adhesion to the substrate and thermal shock resistance.
Graphite electrode antioxidant coating features:
1. High temperature resistant to oxidation and high temperature resistance 1700 °C. It is used for anti-oxidation treatment of graphite electrodes in electric arc furnaces, LF refining furnaces and submerged arc furnaces for steel, alloy and other smelting. Reduce the consumption of unit graphite electrode by 12~20%.
2. The product is inorganic, stable in chemical properties, acid and alkali resistant, non-toxic, harmless and odorless. It will not cause chemical impurities pollution to the smelt and is harmless to the human body.
3. The coefficient of thermal expansion is close to that of graphite material, and it has good thermal shock stability. It is not easy to crack off from the graphite matrix at high temperature.
4. Good sealing property, which can effectively isolate the air from direct contact with the side of the graphite electrode at high temperature, and slow the oxidation speed of the side surface of the graphite electrode.
Antioxidant mechanism of graphite electrode antioxidant coating:
During the use of the graphite electrode, the electrode is directly exposed to the air and is in a high temperature oxidizing environment. The oxidation of the side of the electrode accounts for about 60% of the total electrode consumption. The surface of the paint-coated graphite electrode is dried to form an ultra-high temperature resistant seal coat. The coating can effectively isolate the air from direct contact with the surface of the electrode substrate at an ultra-high level, thereby slowing the oxidation speed of the graphite electrode side and reducing the consumption per unit graphite electrode.
Graphite electrode antioxidant construction process:
1. Stir the paint thoroughly before painting.
2. Use a brush or paint roller to evenly apply the paint to the surface of the electrode. Be careful to make the brush as thick and uniform as possible, otherwise it will easily cause the coating to crack after calcination.
3. After the first painting, let it dry naturally, the coating will dry to a certain extent and it will harden. The coating will harden until it is scratched with fingers without leaving scratches. (Depending on the temperature of the site, it is generally necessary to naturally Dry for an hour or so). Then use the same method to brush the second and third times. Brush at least twice and paint three times better. The total thickness of the coating is controlled to be around 0.8-1.5mm.
4. After the last painting, let the electrode dry naturally for 1~2 hours, let the coating dry fully, and harden before it can work on the furnace.
5. Note that because the coating itself is not electrically conductive, approximately 30% of the circumference of the electrode must be reserved, and the reserved portion serves as the area where the holder copper plate contacts the surface of the graphite electrode substrate.
6. Pay special attention to the fact that when the electrode is connected to the electric furnace, the reserved uncoated portion must be aligned with the conductive copper plate portion of the holder so as not to affect the conduction.
