Corrosion of welding reinforcement height under dynamic conditions

Abstract

The presence of welding reinforcement height (WRH) within oil and gas pipelines can lead to micro-turbulence in localized areas during transportation, resulting in corrosion failure. This study employed a modular reconstruction method to simulate and reconstruct X80 steel welded joints, and investigated the erosion-corrosion behavior at the WRH using wire beam microelectrode, electrochemical impedance spectroscopy, and computational fluid dynamics simulations. The results show that the galvanic current density (GCD) in the weld metal exhibits cathodic behavior, while the GCD in the base metal and heat-affected zone shows anodic behavior. The top of WRH is susceptible to corrosion failure. As the radius of WRH increases, the corrosion rate also increases. Additionally, the corrosion rate increases similarly with an increase in flow velocity. The galvanic corrosion intensity factor (g) is 0.24, and the local corrosion is moderate. This work has scientific significance in ensuring the long-term safe operation of pipelines and reducing the risk of corrosion failure.