| 摘要 |
A nickel-gold plating exhibiting high resistance to corrosion, which has a nickel plating layer formed on a base metal (1) and a gold plating layer (3) formed thereon, characterized in that the nickel plating layer (2) has a corrosion potential being brought close to that of the gold plating layer (3) through the reduction of the sulfur content of the nickel plating layer; or which has a first nickel plating layer (6) formed on a base metal, a second nickel plating layer (7) formed on the first nickel plating layer and a gold plating layer formed thereon, characterized in that the first nickel plating layer has a corrosion potential nobler (higher)than that of the second nickel plating layer. The nickel-gold plating exhibits only a mild local cell phenomenon between the gold plating layer and a nickel plating layer directly thereunder even under corrosive conditions, which leads to retardation of the corrosion through pitting and thus to a satisfactory durability of the plating with relatively thin respective plating layers. Accordingly, the nickel-gold plating achieves a high resistance to corrosion with little impairment of production cost or productivity.
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