Simulated corrosion test of Q235 steel in diatomite soil

Through the study of the corrosion behavior of Q235 steel in actual Yingtan soil and two simulated acidic soils with different water contents, the calculation of corrosion mass losses, and the analysis of the corrosion morphologies and products by means of scanning electron microscope (SEM) and X-ray diffraction (XRD), the results demonstrated that the diatomite soil could simulate the corrosion in actual soil veritably. In both actual soil and simulated soil with 16.4% water content, the corrosion rates of Q235 steel were approximately 0.1 mm/a, the corrosion morphologies were mainly extension and connection of corrosion spots on sample surface, and the corrosion products were composed of α-FeOOH, γ-FeOOH, Fe3O4 and Fe2O3. When other media conditions remained unchanged, the corrosion area of Q235 steel was larger in simulated soil with 34.5% water content, and the corrosion rate reached 0.48 mm/a after 360 h of corrosion, which was nearly 5 times as the value in actual soil. Compared with the corrosion products in actual soil, the proportion of γ-FeOOH in simulated soil with 34.5% water content was higher, and the wα-FeOOH/wγ-FeOOH ratio was 1.4, which was only 1/3 of the value in actual soil.