| 摘要 |
1,146,594. Coating with metals; electroplating with chromium. ASSOCIATED CHEMICAL COMPANIES Ltd. June 7, 1966 [July 1, 1965], No.27956/65. Headings C7B and C7F. A ferrous substrate is chromized by forming, e.g. by electrolysis, spraying or rolling a powder, a porous coating of chromium which may also contain nickel or aluminium, heating (400 to 700‹C .) the coating in a stream of a non-oxidizing gas containing a hydrogen halide, and subsequently heating at a temperature of at least 750‹ C. preferably 800 to 1000‹C. A porous Cr coating is formed electrolytically by degreasing a steel sheet, cleaning anodically in 50% sulphuric acid, and then plating in a catalyzed chromic acid plating bath with a current density of 300 A/sq.ft. |
