The corrosion resistance of X80 pipeline steel was investigated in simulated solution of Geermu soil in Qinghai province

by using mass loss method

electrochemical measurement

scanning electron microscopy and X-ray diffraction.The results showed that the average corrosion rate of X80 steel decreased obviously

but corrosion tendency increased.This was induced by the change of corrosion morphology from uniform corrosion to pitting corrosion.Cathodic reaction was dominated by oxygen depolarization reaction.The corrosion product was basically FeOOH (surface layer) and Fe3O4 (inner layer).The corrosion resistance and corrosion morphology of X80 steel samples was dependent on the integrity and compactness of corrosion product films.The content of Cl- dominated the corrosion severity.