| 摘要 |
PURPOSE:To enable an inhibitory film of nitriding to be formed by simple treatment and at a low cost by coating a hardened inorg. compound film forming agent as an inhibitor of nitriding for a part not to be nitrided when the surfaces of various steel products are soft-nitrided in a salt bath. CONSTITUTION:When a specified surface of carbon steel, cast iron, cast steel or alloy steel is soft-nitrided in a salt bath to enhance the fatigue strength, wear, corrosion and heat resistance, etc., a hardened inorg. compound film forming agent is coated independently or mixing with aggregate as an inhibitor of nitriding for coating a part not requiring soft-nitriding. The film forming agent contains water soluble alkali metal silicate, water dispersible silica sol, water soluble phosphate, alkyl silicate and its partial hydrolyzate, org. silicate or the like as a binder. If necessary, to 10-10,000pts.wt. of the binder may be added 100pts.wt. inorg. oxide such as alumina and silica plus nitride or the like in the form of needles, fibers, flakes or lumps. |
