| 摘要 |
1,225,592. Surface-treating galvanized steel. NIPPON KOKAN K.K. April 25, 1969 [April 25, 1968], No.21364/69. Heading C7F. At least one halide, nitrate or sulphate of a metal to alloy with the zinc is applied uniformly either as powder or an aqueous solution on to the surface of galvanized steel which is at a temperature above 300‹C., thereby forming a thin alloy layer of said metal and zinc on the surface of the coating. The zinc on the surface of the galvanized steel may be molten as a result of having just come from a hot-dip galvanizing bath, or it may be solid, at a temperature of 418‹ down to 300‹C., having been cooled after hot-dip galvanizing but prior to treatment with the metal salt. The metal halide, nitrate, or sulphate may be that of Fe, Cu, Cr, Ni or Sn, with the former being preferred, and the salt may be applied to the surface together with a reacting accelerator which may be a halide or complex fluoride of B, Ti, or Si, of a Group I or Group II metal, or of ammonium. In the case of spraying the metal salt in aqueous solution, HCl or HNO 3 may be used to adjust the acidity; in the case of powder spraying the powder has size 30-150 mesh (Tyler). |
