Contact Corrosion
When two disimiliar metals are in contact without a protective barrier between them and they are in the presence of liquid, an electrolytic cell is created. The degree of corrosion is dependent on the area in cantact and the electro-potential voltage of the metals concerned. The less noble of the metals is liable to be attacked, i.e. zinc will act as a protector of steel in sea water wheras copper or brass wo;; attack the steel in the same enviroment.
