Effects of Sodium Thiosulfate on Corrosion Dynamics of Q235 Steel in Alkaline Environment

Effects of sodium thiosulfate on the corrosion dynamics of Q235 steel in an alkaline solution were studied by weight loss testing, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results indicate that the corrosion degree of Q235 steel increased with the concentration of sodium thiosulfate. The kinetic reaction order and rate constant were obtained through the law of mass action. The corrosion rate showed a power function with the corrosion time for Q235 steel in the alkaline solution containing sulfur. The corrosion products were mainly composed of Fe, O and S elements. The sulfides were FeS and FeS₂ whose particles were loose and fall off easily, and the corresponding oxide was Fe₃O₄.