Graphitic electrode with protective coating

摘要

The protective coating consists of three layers. As alloying additives in the first and second layer or only in the second layer are used, nickel and iron or their oxides whereby the nickel content is from 0.05 to 0.95% and the iron content is, respectively, from 0.1 to 15% with regard to the total amount of aluminum. Both layers are submitted to heat treatment with surface density of the heat flow from 8 to 16.106 W/m2. The third layer consists of aluminum with technical grade purity. The thus described graphitic electrodes are used in arc furnaces.