| 摘要 |
PURPOSE:To form a layer with superior resistance to corrosion due to a hot gas contg. HCl by successively forming the 1st layer of a mixture consisting of Cr and Ni in a specified ratio and the 2nd layer different from the 1st layer in composition by spraying on a metallic surface. CONSTITUTION:The 1st layer of a mixture I consisting of Cr and Ni in 2/8- 8/2 weight ratio of Cr/Ni is formed by spraying on a metallic surface which is exposed to a hot gas contg. HCl. The 2nd layer consisting of 30-70wt% mixture I and 70-30wt% alkaline substance or ceramics is formed by spraying on the 1st layer. Said spraying is carried out by applying plasma spraying. The preferred ceramics is aluminum oxide, and the most suitable alkaline substance is sodium carbonate. To the mixture I may be added <=3% Nb, Ta or other element, and the 3rd layer of ceramics may be formed on the 2nd layer. |
