Effect of temperature on the electrochemical corrosion behavior of X52 pipeline steel in NS4 simulated solution

Abstract

In this study, the electrochemical corrosion performance of both the base material and welded joint of X52 pipeline steel was analyzed at various temperatures (room temperature-RT, 30 °C, 50 °C, and 80 °C) using microscopic characterization techniques and electrochemical methods in a simulated soil solution (NS4). Additionally, the influence of temperatures on the electrochemical corrosion behavior of the X52 pipeline steel base material and welded joint was examined. The findings indicate that the open circuit potential (Eocp) of the base material and welded joint shifts in the negative direction with increasing temperature. The corrosion current density increased from 30.7 to 110.2 μA∕cm2 and from 19.5 to 100.2 μA∕cm2, respectively, while the polarization resistance dropped from 637.3 to 272.6 Ω•cm2 and from 961.3 to 360.7 Ω•cm2. Notably, anodic dissolution controls the corrosion process of the base material and welded joint of X52 pipeline steel at room temperature. Furthermore, the charge transfer resistance (Rt) of the base material and welded joint gradually decreases with increasing temperature, and the corrosion process transforms into cathodic diffusion control. Additionally, the welded joint of X52 pipeline steel exhibits superior corrosion resistance to that of the base material at the same temperature.