近中性土壤中20(上标 #)钢管道材料腐蚀行为与机理的研究

Corrosion process and mechanism of 20(superscript #) low-carbon steel in near-neutral in soil are studied by experiments of buried specimens in laboratory. In three kinds of soils, the corrosion features and products are analyzed by EDS and XRD, and the relation of corrosion rates, open-circuit potential and polarization curve with times are tested. The results indicated that corrosion rates changed incessantly along. On the condition of the same times, specimens and different soil samples, the corrosive degree of 1(superscript #) and 2(superscript #) specimens are serious, but 3(superscript #) specimen is a little serious. The corrosion products are main non-crystalloid, Fe(OH)3 and Fe2O3. The change rules of different times and soils are different, and are accordant with that of corrosion rates. The corrosion mechanism is discussed, in near-neutral soils, oxygen is deoxidized and OH(superscript -) ions are created in cathode area, iron is oxidized and the hydration of Fe(superscript 2+) ions is created with water from soil in anode area, and Fe(superscript 2+) are converted into more steady products Fe(OH)3and Fe2O3.