無電解ニッケル-タングステン-リン合金めっき皮膜の鉄素地に対する防食性について

抄録

Nickel-tungsten-phosphorus alloy films deposited on iron by electroless plating (pH 5 to 9) were examined to determine their dissolution behavior and corrosion protective effect on the iron substrate in 5%-NaCl solutions (pH=67, and 80). It was found that the tungsten content in the film increased with increasing deposition pH, and that the dissolution rate of the film incseased with increasing tungsten content. The protective effect of the films on the iron substrate increased with increasing tungsten content. The corrosion resistance of the films is discussed in terms of the corrosion potential and the number of pinholes in the films.