Effect of Temperature on the Corrosion Behavior of 1Cr Steel in CO₂ Environment

Abstract

For improving the corrosion resistance of oil pipes and taking into account certain economic benefits, steel with low chromium content has received increasing attention from oil and gas fields.In this paper,a high-temperature high-pressure autoclave was used to simulate the CO2 corrosion environment, for investigating the effects of temperature on the weight loss corrosion behavior and electrochemical corrosion behavior of 1Cr steel.Moreover, the morphology and composition characteristics of corrosion products on the surface of 1Cr steel at different temperatures were analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD).Results showed that in the range of 60 ～120 ℃, the corrosion rate of 1Cr steel first increased and then decreased with the increase of temperature, and reached the maximum value at 80 ℃.As the temperature increased further, the corrosion product film became denser and more uniform,which increased the charge transfer resistance.At the same time,the enrichment of Cr in the product film at high temperatures also increased the resistance of the corrosion product film, which eventually led to a decrease in the corrosion rate of 1Cr steel at 100 ℃and 120 ℃.

Keywords

• 1cr steel； temperature； co₂ corrosion； electrochemical corrosion