1. Bimetallic Contact

(d) Wet Atmosphere

If the wet surface is maintained for a longer duration, in particular if salt particles are present, bimetallic corrosion is aggravated. The design of components must not allow the retention of layer of water on the surface. A smooth polished surface would not allow water retention. A smooth design of polished surface sloping downwards would not allow the retention of water layer for longer period of time. More examples of good and bad channel designs are shown in figure below.