Effect of Temperature on the Electrochemical Corrosion Behavior of X80 Steel in Silty Soil Containing Sodium Chloride

The corrosion behavior of X80 pipeline steel in silty soil containing chloride ions at different temperatures was investigated using different electrochemical techniques. Scanning electron microscopy and energy-dispersive spectroscopy were used to characterize the corrosion morphology and physicochemical properties of the X80 steel. The lower chloride ion concentration and the ambient temperature were associated with the lower the unfrozen water content in the soil and the easier it to form an anoxic corrosion environment. As the chloride ion concentration increased, the corrosion rate increased at − 10 °C and first increased and then decreased at − 20 °C. The steel corroded surface were present irregular elliptical uncorroded areas in a soil environment at the sub-zero temperature, which may be caused by the liquid–solid phase transition hindering the transportation of the reducing medium. The rust layers in a positive temperature soil environment were present relatively dry. This phenomenon is due to the current density is high, and the exothermic process is evident.