Abstract
We studied corrosion of alloy steel which is used in oil well pipe under high temperature and CO2 environment. Corrosion tests of the specimens with different quantity of Cr addition was carried out. Cross section and surface morphology of corrosion products were analyzed by SEM and EDX. The corrosion products were changed from crystal state to film state by Cr increase in the alloy. The crystal form corrosion products were FeCO3, and EDX analysis showed that there were Cr concentration in the film form corrosion products. The dense structured Cr compound was formed by increasing Cr content in the alloy, and the corrosion resistance was improved by the suppressed dissolution of Fe in the dense structured Cr compound
