Response of mild steel corrosion rate in h2so4 solution to the input concentration of hypoxanthine as inhitor and its inhibition efficiency

Abstract

This paper evaluates the response of mild steel corrosion rate to the inhibitor (hypoxanthine) concentration and inhibition efficiency using a derived empirical model; ξ = Ҽγ^-K + Ϧη^-N. In the course of the derivation, the range of values for the process parameters used were 2.46 x 10^-4 - 2.98 x 10^-4 (g h^-1cm^-2), 0.002-0.01(mol dm^-3) and 53.98- 61.94 (%) for corrosion rate, inhibitor concentrations and inhibition efficiencies respectively. The validity of the model is strongly rooted on the core model structure; ξ – Ϧη^-N ≈ Ҽγ^-K. The model-predicted results agree with previous research on the inverse relationship between the corrosion rate and inhibitor concentration & inhibition efficiency. The standard error incurred in predicting the model based corrosion rates relative to the actual results was < 0.04%, implying over 99% model confidence level. Corrosion rate per unit inhibitor concentration and inhibition efficiency were evaluated as - 0.0065 & - 0.00625 g h^-1 cm^-2 /mol dm^-3   and - 6.53 x 10^-6 & - 6.28 x 10^-6 g h^-1 cm^-2 / %, using the actual and model-predicted results respectively. Furthermore, the correlations between these highlighted parameters, as evaluated from both results were all > 0.96. The overall maximum deviation of model-predicted corrosion rate from actual results was 5.62%.