To provide a painting material capable of promoting permeation of an oxidation prevention material into a graphite electrode, improving the adhesion property of the prevention material when temperature is high, and suppressing obstruction of electric conductivity with reduced cost.
The oxidation prevention material is aqueous solution containing 1 to 20 wt.% of phosphorus pentaoxide, 0.1 to 10 wt.% of anhydrous boric acid, 0.1 to 5 wt.% of magnesium oxide, and 4 to 40 wt.% of colloidal silica, and phosphoric acid, boric acid, magnesium hydroxide, and colloidal silica stock solution are dissolved in it so that its acidity becomes pH 4 or less. When it is impregnated in the graphite electrode, consumption due to surface oxidation during operation of the electrode can be suppressed and prevented. At this time, the oxidation prevention material impregnated in advance from a surface of the electrode is vitrified by heat that the electrode receives during steel manufacturing operation so that oxidation prevention action is obtained in a product produced at high temperature, that is, contact with oxygen can be shut off.
OZAWA HIROSHI
YAMAGAMI YOSHIYUKI
NIKKEI SANGYO KK
NIPPON ELECTRODE KK