Corrosion behavior of Q345 and Q235 steels in simulated neutral soil solution

Abstract Q345 and Q235 steels are widely used in infrastructure and manufacturing. Examining the corrosion behavior of two types of steel in a neutral soil environment can facilitate the assessment of the service life of the steel machinery, thereby mitigating potential corrosion failures. In order to investigate the corrosion and mechanism of Q345 and Q235 steels in the neutral soil solution, an electrochemical test, scanning electron microscopy, and X-ray diffraction were employed to analyze the corrosion morphology, corrosion product, and electrochemical polarization curves. The results showed that no visible pitting pits were observed on the surfaces of Q345 steel and Q235 steel. The corrosion types were mainly overall corrosion in the simulated neutral soil solution. The microstructure of Q235’s corrosion product exhibits greater compactness, facilitating the formation of Fe 3 O 4 . This compound demonstrates excellent binding ability with the metal matrix and hinders the continuous corrosion of the steel. Q235 steel has better corrosion resistance with a lower corrosion rate than Q345 steel in the simulated neutral soil solution. These findings contribute valuable information for material selection considerations in manufacturing machinery in neutral soil environments.