Study on the process of oxidation resistance composite coating on graphite electrode by dipping method

Graphite material is a kind of conductive material with excellent thermal shock resistance, is an important strategic mineral resources, widely used in iron and steel smelting, aviation, aerospace and other fields. However, the graphite electrode is easy to be oxidized in the air, resulting in a large amount of graphite electrode loss. In this paper, a new impregnation material is used to prepare graphite electrode oxidation resistance coating, by changing the ratio of raw materials, impregnation times, sintering process and other process parameters to prepare samples, and then oxidation resistance experiment to characterize its antioxidant capacity. The optimum technological parameters of graphite electrode coating obtained in this paper are: The content of antioxidant is Si 4.6%, SiC 5.8%, TiO₂ 6.9%, Al₂O₃ 5.4%, H₃BO₃ 3.7%, carboxymethyl cellulose 2.6%, deionized water 70%, hot impregnation twice, after sintering in nitrogen atmosphere at 400 ℃ for 30 min, In the range of 800 ℃~1200 ℃, the weight loss of the graphite samples with anti-oxidation coating is reduced by 7.3%~11.3%. The coating can protect the anti-oxidation of the graphite matrix well.