Effect of Gas Flow Velocity on Tarnish Kinetics of Contact Materials

Experiments were conducted to show the effects of gas flow velocity in the test chamber, the kinds of corrosive gases, and their concentration on the tarnish kinetics of copper and silver. The gas flow velocity was varied from 0.4 cm/s to 42 cm/s. H
2
S was selected as the corrosive gas in the single gas test condition, and H
2
S, NO
2
, and SO
2
were selected as the corrosive gases in complex conditions, at room temperature and a relative humidity of 70 percent.