Long-Term Prediction of Atmospheric Corrosion Loss in Various Field Environments

This paper deals with the prediction of long-term atmospheric corrosion in different field environments using the power-linear function. A method for the calculation of exponent n and stationary corrosion rate a in the power-linear function is proposed based on the 1- and 8-y corrosion loss results (C-1 and C-8 ) of the ISO CORRAG program. The response surface method and the artificial neural network methodology are used to obtain the accurate estimation of C-1 and C-8 in different locations using environmental variables. Considering the uncertainty of the model and the experimental data, the confidence intervals of n and a are also calculated. It is shown that the long-term predictions obtained by the proposed method coincide with the actual corrosion loss within +/- 30% relative error. The estimations for the range of the long-term corrosion loss are also reliable. The proposed method is helpful in extrapolating the knowledge of corrosion management to different field environments where corrosion data are not available.