| 摘要 |
PURPOSE:To shorten sharply the period of time for drying the coating material, by adding calcium hydroxide to the mixture of powdery inorganic substance as the coating material for the coated electrode, kneading with the aqueous solution of water glass and applying the obtained mixture on the core material of welding rod. CONSTITUTION:When the coating material for arc welding electrode is prepared by kneading the powdery mixture consisting of inorganic oxide, fluoride, alloy, etc. with the aqueous solution of water glass, the powder of calcium hydroxide of 0.1-5 5% is added to the above powdery mixture. The obtained mixture and the aqueous solution of water glass are kneaded and are applied on the core wire of welding rod. Owing to the chemical reaction of water glass and calcium hydroxide, the formation of colloidal film of water glass is suppressed, the compulsive drying at high temperature can be carried out without performing the spontaneous desiccation, the period of time for drying can be shortened sharply and, moreover, the coated electrode which does not cause the cracking of coating material due to drying and the falling-off of coating material at the welding, is obtained. |
