Corrosion behavior of eight types of steels in simulated extreme cold atmosphere

• For the first time, corrosion resistance and corrosion mechanisms of various steels in extremely low-temperature atmospheric environments are presented. • It has been confirmed that in low-temperature environments, rust layers formed on steels, specifically those that are thick, uniform, and contain small pores and longitudinal cracks, exhibit a superior rust inhibition effect. • Utilizing density functional theory (DFT), the influence of ferrite, cementite, and residual stress in different steels on corrosion resistance is explained from the perspective of work function. Corrosion behavior of eight types of steels in a simulated extreme cold atmosphere was examined utilizing mass loss analysis, scanning electron microscopy (SEM), Raman spectroscopy, electrochemical measurements and density functional theory (DFT) calculations. Findings reveal that corrosion kinetics of these carbon steels is highly related to the power function relationship, expressed as Δ m = At n . After 240 h of corrosion, steel 6#, 7#, and 8#, which contain higher concentrations of Cu, Cr, and Ni, exhibited lower corrosion rates than that of the remaining five carbon steels. Primary compositions of rust layers formed on all eight steels comprised α -FeOOH, α -Fe 2 O 3 , γ -FeOOH, γ -Fe 2 O 3 , and Fe 3 O 4 . Notably, sulfate promotes the preferential formation of α -FeOOH, while low temperatures facilitate emergence of α -Fe 2 O 3 . Furthermore, the presence of uniform, fine grains without distortion, coupled with evenly distributed cementite, contributes to the development of dense and uniform corrosion products. Among the rust layers observed, the thick and uniform layers, characterized by minimal holes and longitudinal cracks, exhibit the most effective rust inhibition properties.