The graphite electrode can be prevented from oxidation by applying a protective coating to the electrode surface. The following describes some methods to prevent oxidation of graphite electrodes:
1, first on the surface of the graphite electrode processing a shallow groove, the purpose is to make the ceramic layer can be firmly attached to the surface of the graphite electrode, and then the graphite electrode is heated to about 250℃ heating furnace, and then the metal spray gun is used on the electrode. A thin layer of aluminum is sprayed on the surface, and a layer of cermet paste is sprayed on the aluminum layer, and then carbon arc sintering paste, spray paste and arc sintering are repeated 2-3 times to make the cermet layer have sufficient thickness.
Cermet has a resistivity of 0.07-0.1pm, lower than that of graphite electrodes. 900℃ insulation for 50h, not breathable, coating decomposition temperature 1750-1800℃. The element composition of the coating has no effect on the molten steel. Increasing the raw materials, electricity and labor used for the antioxidant coating will increase the cost of the graphite electrode by 10%, but the single consumption of the graphite electrode per ton of EAF steel can be reduced by 20-30% (the result is used in ordinary electric furnaces). Since the coating is a brittle material, cermet is a brittle material, avoid collision when used, do not make the coating fall off.
2, reduce exposure to air: graphite electrodes should be stored in a dry, airless place to prevent contact with water and air. This will help prevent oxidation.
3. Lower operating temperature: Operating the electrode at a lower temperature can reduce the chance of oxidation. This can be done by reducing the current or increasing the electrode spacing.
4, the use of protective gas: the operation can use argon or nitrogen and other protective gas to prevent oxidation. The gas helps to create a protective atmosphere around the electrode.
5. Proper cleaning: Properly cleaning the electrode before operation can remove any impurities or contaminants that may cause oxidation.
Scope of application: Suitable for graphite electrode, anode carbon block, electrolytic aluminum plant, graphite mold, graphite crucible and other graphite products surface sealing anti-oxidation, sealing anti-corrosion, prolong the service life of graphite products. At least 30%, increase material strength.
