Influence of temperature on the cathodic polarization behavior and calcareous deposit properties of X65 steel in sea water

Purpose This paper aims to investigate how cathodic polarization behavior significantly affects the selection of cathodic protection parameters and the effectiveness of protecting underwater metal structures. Factors such as water depth and operating conditions impact seawater temperature, making it crucial to understand the effects of temperature on cathodic protection parameters for underwater pipelines. Design/methodology/approach In this paper, potentiostatic polarization was carried out by three-electrode method, and morphology, X-ray diffraction and electrochemical analysis. Findings It was determined that the stable current densities at the minimum negative potential (−0.8 V SSC ) for pipeline steel varied at different temperatures: 7°C, room temperature and 60°C. The cathodic protection potential corresponding to the lowest stable current density was observed to be −1.0 V SSC at 7°C and −0.95 V SSC at room temperature and 60°C. Originality/value This study elucidates the mechanisms by which different temperatures affect the protective performance of calcareous deposits and current densities.