Temperature-Dependent Corrosion Behavior of Martensitic Stainless Steel in Simulated Seawater Environments

Abstract

In this work, the temperature-dependent corrosion rates of AISI 440 martensitic stainless steel are explored in simulated seawater (3.5 wt% NaCl solution) with temperatures typical for offshore platforms. Cylindrical samples are corroded for 17-85 hours at 25 °C, 30 °C, and 60 °C, with the latter showing increased corrosion rates of up to five times the room-temperature rates, reaching a five-fold increase in corrosion rates from 25 °C to 60 °C. Monte Carlo simulation results using n = 1,000 iterations are used to quantify the probabilistic distribution of the corrosion rates, suggesting increased variability in the corrosion rates at higher temperatures, with standard deviations within triplicate experiment groups also being larger. Arrhenius analysis revealed an activation energy of 38.7 kJmol⁻¹, while the Q₁₀ analysis suggested an 80% increase in the corrosion rates over 10 °C increments. The results verify the prominence of temperature in the chloride-induced corrosion process of martensitic stainless steel. An integrated experimental and simulation framework has been developed that constitutes the principles of temperature-coupled corrosion rates, thereby aiding in the determination of the temperature effects on the corrosion process, which can then assist in the inspection and predictive evaluation of the structure. These results highlight the significance of temperature in the choice of materials and the assessment of subsea structures.