Corrosion of Mild Steel in Nitric Acid Solutions Under Isothermal and Heat Transfer Conditions

The main objective of this work is the study of corrosion behavior under heat transfer conditions, i.e., in the presence of temperature gradients. Quantitative assessment of this factor necessitated performing complementary experiments to investigate the kinetics of the corrosion process and develop a mathematical rate expression correlating the effects of pertinent operating conditions. Results indicated a first order dependency of the initial corrosion rate on acid concentration, which appears consistent with a diffusion-controlled mechanism. Further support to this postulate was furnished by the results obtained for the effect of stirring. Close predictions for the extent of corrosion taking place under temperature gradient conditions could be made on the basis of the isothermal data utilizing the differential averaging technique.