An Investigation of quantitative and qualitative analysis of synergistic environmental effects on current requirement for cathodic protection of coal tar polyamide coating in artificial seawater

In this paper, current requirement for cathodic protection of low carbon steel that coated by coal tar polyamide coating under synergistic effect of environmental parameter has been studied. This project is mainly focused on the effect of temperature, velocity, salinity and pH, which are the most important factors, that can affect on protective current from corrosion. Assess the percentage of cumulative and individual effect of factors on protective current was computed by the analysis of variance (ANOVA) via full two-level factorial experiment. Moreover, qualitative analysis has been studied to predict the path variation of current required for cathodic protection under individual and cumulative parameters. The overall results, that get from these two analysis of individual and cumulative effect of parameters on protective current, was shown that cumulative effect of parameters are more important and effective than individual effect of parameters on current requirement for cathodic protection in seawater. Considerable, according to the results, among the factors, temperature is the most affecting factors on protective current for cathodic protection and coal tar polyamide coating has shown good resistance against pH variations.