A comparative study on the corrosion behavior of Q235 steel in saturated acidic red and yellow soils

Purpose The purpose of this paper is to study the corrosion behavior of Q235 steel in saturated acidic red and yellow soils. Design/methodology/approach The corrosion behavior of Q235 steel in saturated red and yellow soils was compared by weight-loss, SEM/EDS, 3D ultra-depth microscopy and electrochemical measurements. Findings R p of the steel gradually increases and i corr gradually decreases in both the red and yellow soils with time. The R p of the steel in the red soil is lower, but its i corr is higher than that in the yellow soil. The uniform corrosion rate, diameter and density of the corrosion pit on the steel surface in the red soil are greater than those in the yellow soil. Lower pH, higher contents of corrosive anions and high-valence Fe oxides in the red soil are responsible for its higher corrosion rates and local corrosion susceptibility. Originality/value This paper investigates the difference in corrosion behavior of carbon steel in saturated acidic red and yellow soils, which can help to understand the mechanism of soil corrosion.