Influence of Buffer Capacity, Chlorine Residual, and Flow Rate on Corrosion of Mild Steel and Copper

摘要

The corrosion rates of mild steel decreased as buffer capacity was increased with pH at constant alkalinity. The corrosion-promoting effect of ionic strength, however, appeared to predominate over the buffer action in water systems with relatively high total dissolved solids and chloride levels. The enhanced corrosion of mild steel and copper due to a free chlorine residual was related to the strong oxidation potentials of hypochlorous acid and hypochlorite ions. Corrosion rates were faster with higher flow rates, but other hydraulic and environmental factors also need to be considered when corrosivities are compared.