Predicting the External Corrosion Rate of X60 Pipeline Steel: A Mathematical Model

The need for predicting pipeline service life and improving risk assessment relating to corrosion hazards requires establishing a correlation between the rate (CR) of steel its coating condition, cathodic protection (CP) levels surrounding soil conditions. This paper presents systematic study CR bare coated—with without dent or holiday defect—X60 in simulated field environments. Three CP scenarios, i.e., no, optimized, over-protection, were studied cover wide range possible conditions that may encounter field. Two types salt solutions (sodium chloride sodium sulfate) with variation temperatures (10 °C, 40 65 °C) pH values (2, 7, 12) investigated simulate different corrosivity. A mathematical model was developed reveal impact various parameters their interactions on X60 steel. condition most important factor. individual effects other factors including temperature, pH, composition not shown be significant. Instead, temperature composition, particularly interaction appeared more determining overall CR.