| 摘要 |
PURPOSE:To form a thermally sprayed film having excellent heat resistance, heat insulating property and wear resistance at a low cost by thermally spraying the grains or gamma type dicalcium silicate (gamma-2CaO.SiO2) contg. oxide impurities at a specific ratio onto the surface of a steel sheet. CONSTITUTION:The gamma type dicalcium silicate (gamma-2CaO.SiO2) obtd. by calcination of calcareous raw materials and siliceous raw materials in an electric furnace is ground to form the powder contg. 1 or >=2 kinds of impurities such as Al2O3, Fe2O3, MgO, Na2O and K2O in a 0.25-10wt.% range and consists of the balance gamma-2CaO.SiO2. A binder such as polyvinyl alcohol, methyl cellulose, sodium silicate or starch and water are added to this powder and the mixture is stirred and sprayed to granulate the same to fine grains of 10-100mum grain size. The grains of the gamma-2CaO.SiO2 are thermally sprayed by plasma onto the surface of the steel sheet, by which the surface coating layer having the excellent heat resistance, heat insulating property, etc., is formed of the inexpensive raw materials. |
