The Use of Sodium Dichromate Pretreatment for Enhanced Marine Corrosion Resistance of C70600

A series of pretreatments have been evaluated for effectiveness in minimizing the extent of corrosion incurred by C70600 during initial periods of exposure in seawater. By minimizing this corrosion, a reduction in the rate of copper released to the environment can be achieved. The quantities of total copper discharged during the start-up of a new condenser system, for example, might therefore be reduced. The pretreatments examined included a variety of inorganic and organic chemicals. The inhibitive powers of the pretreatments were assessed through a variety of tests in natural seawater. Based on the rates of copper release during the initial eight hours of exposure in seawater at 50 C, several pretreatments appear promising. The sodium dichromate pretreatment has proven to be the most consistent in reducing initial corrosion rates and has been shown beneficial in reducing longer-term corrosion rates of C70600 in seawater. Additionally, it does not appear to impair other properties of C70600 such as biofouling resistance and erosion-corrosion resistance.