Statistical analysis of the corrosion inhibition performance of three inorganic compounds on mild steel acid media

Abstract

Sodium benzoate, zinc benzoate and zinc bromide were studied for their corrosion inhibition effect on mild steel in 0.5 M H2SO4 and HCl solution. Data obtained showed the performance of the inorganic compounds significantly varied with respect to exposure time. Zinc bromide (ZBM) exhibited the most effective inhibition performance on mild steel in H2SO4 solution with optimal inhibition value of 90.96% at 50% concentration, corresponding to corrosion rate of 1.330 mm/y. Sodium benzoate (SB) displayed the least effective inhibition performance with optimal value of 50.5% at 70% concentration corresponding to corrosion rate of 7.284 mm/y. Zinc benzoate (ZB) performed most effectively in HCl solution with inhibition value of 70.17% at 50% inhibitor concentration corresponding to corrosion rate of 1.251 mm/y while zinc bromide contrary to its performance in H2SO4 solution displayed weak inhibition performance in HCl solution with peak value 55.40% at 30% concentration corresponding to corrosion rate of 1.870 mm/y. Statistical data showed in H2SO4 solution, inhibitor concentration significantly influenced the inhibition performance of ZB and ZBM compounds with values of 98.37% and 94.57%. The effect of exposure time was negligible but statistically relevant. The statistical relevance value obtained for SB inhibitor concentration and exposure time are 65.96% and 25.20%. In HCl solution, the statistical relevance of ZBM and ZB exposure time at 58.4% and 41.51% is greater than the corresponding value for concentration at 32.46% and 38.14%. However, SB concentration overwhelmingly influenced the performance of SB compound at statistical relevance value of 95.75%.