Influence of surface temperature on atmospheric corrosion behaviour of 1008 carbon steel in sub-Arctic Alaska

Abstract

This study aims to measure the surface temperature of 1008 low-carbon steel samples fully and partially exposed to solar irradiance, characterise their corrosion rates under varying sub-Arctic environmental conditions, and investigate any potential relationships or effects between surface temperature and atmospheric corrosion. An experimental rack was developed to expose small samples in a shaded and unshaded orientation, while still open to the ambient environment. Using previously established exposure sites across Alaska, a 6-month exposure cycle was conducted to collect surface temperature profiles, weather data, and mass loss corrosion rates. Post-processing also included reviewing weather data, scanning electron microscopy, and an energy dispersive X-ray analysis. Results concluded that exposed samples equilibrate to much higher temperatures than that of ambient temperature and shaded coupons (∼15°C–20°C). However, the Pacific Spaceport Complex Alaska (PSCA) exposure site with the least thermal variance exhibited the highest differential in corrosion rates between the shaded and unshaded samples. This difference is found to have stemmed from excessive deposition of airborne Cl⁻ ions rather than elevated surface temperatures. Although no strong correlation is deduced from this study, further research into this matter is warranted, given the changing and evolving ecosystems of Alaska.