二層ニッケルメッキと各種腐食試験法の比較

抄録

In general, it is considered that corrosion resistance of plating depends upon the varieties and thickness of plating. Moreover, the appearance of rusting is varied with test methods.
The experiments were conducted to investigate the correlation between the corrosion tests by salt spray, CASS, corrodkote, etc. and the exposure in the outdoor air; and also to determine the best method for testing duplex nickel plating.
The results were as follows:
i) Corrosion resistance of duplex nickel plating is higher than that of single nickel plating.
ii) In duplex nickel plating, minimum thickness of 20μ is required for high resistance.
iii) Copper plating, which is the substrate of duplex nickel plating, has no correlation with the resistance.
iv) The most intimate correlation between accelerated corrosion test and outdoor exposure is seen in corrodkote test.
v) When the corrosion degree is very low or very high, rating number corresponds well with the percentage of corroded area (by section method), however, when it is in the middle degree, there is no correspondence between the both.