Protective coating for reducing graphite electrode consumption and its production method

Abstract

The invention disclosed a kind of protectant paint which is used to reduce the consumption of the graphite electrode. The ingredient of the paint includes B2O3:5-8%, MoSi2:8-15%, TiO2: 5-10%, Cr2O3:3-10%, Al2O3:3-10% and sulfonate silicon resin:40-65%. The preparing method includes the following steps: pre-melting and sintering the powder granule; pulverizing and sieving the material, the powder with -180-+300 screen mesh is group A filling while the powder with -300 screen mesh is group B filling; mixing the two groups of fillings at a ratio of 7:3 to get the solid filling; because of the add of the trace moly silicon which has similar coefficient of expansion due to heat to the graphite, the smear layer can keep similar coefficient of expansion due to heat to graphite in different temperature intervals while raising the temperature; the invention can control the grain size of the paint components to form the steady and successive smear layer with gradient structure and prevent the stripping or flaking of the smear layer so as to increase the intensity of the smear layer and realize effective protection .

Description

Technical field: [0001] The invention belongs to the technical field of metallurgy and surface engineering, in particular to a protective coating for reducing consumption of graphite electrodes used in electric arc furnaces and external refining ladle furnaces and a production method thereof Background technique: [0002] Graphite electrodes are indispensable and important materials for electric arc furnaces and external refining ladle furnaces. Excessive consumption of graphite electrodes is the main problem of electric furnace steelmaking and LF refining. At present, the average unit consumption of graphite electrodes for electric furnaces in my country is 7-8kg / t steel, accounting for about 8% of the cost of electric furnace steelmaking. The average consumption of graphite electrodes in major steel-producing countries in the world is less than 5kg / t steel, and the best level in the world is 2.4kg / t steel. [0003] Graphite electrodes used by metallurgical enterprises are...

AI Technical Summary

Problems solved by technology

Such as U.S. Patent No.4588700 and Chinese Patent CN1052878 combine carbide, nitride and TiO with phosphosilicate glass, etc. 2 Anti-oxidation coatings made of graphite electrodes; Japanese patent publication 46-35602 and European patent EP0134789 use mullite, SiC and SiO 2 Carbon paint is made as the main filler; Chinese patents CN103585 and CN1070933 use refractory materials and organic binders to make primers and surface coatings; Chinese patent CN1354206A uses water glass as a binder combined with refractory materials to make graphite electrode anti-oxidation coatings , the biggest disadvantage of this kind of coating is that the coating is not easy to dry and cannot be used

Although the above methods can protect the graphite electrode to a certain extent, due to the large difference in thermal expansion coefficient between the coating and the graphite electrode during the heating process of the graphite electrode, it often leads to local peeling or peeling off during the heating process of the graphite electrode, directly Affect the use effect, and these methods use a large amount of organic binders, resulting in highly volatile decomposition of the coating during use, resulting in too many coating pores, unable to form an effective continuous coating, and weakening the protective effect