Corrosion of galvanised steel in synthetic mine waters

AbstractThe corrosion resistance of a silicon killed, galvanised steel plate has been determined in two synthetic mine water solutions using electrochemical and mass loss measurements. It has been estimated that the lifetime of galvanised coatings in still, naturally aerated solutions is in excess of 20 years. The effect of solution temperature between 20 and 40°C and coating constitution has been investigated and shown to have only a minimal effect on the predicted lifetime. Conversely, turbulent conditions in the mine water lead to a significant increase in corrosion rate. The presence of adherent corrosion products on the surface of the coating has a major influence in determining the corrosion rates in both solutions investigated. A comparison is also made between electrochemical polarisation methods and mass loss measurements for the calculation of corrosion rates.