Effect of SAW fluxes on electrochemical corrosion & microstructural behavior of API X70 weldments

High-performance pipeline steels are frequently used for storage, transportation and energy development applications. Submerged arc welding finds its application to weld thick pipes. Design and development of appropriate welding fluxes provide good structural integrity properties in severe service environments. The present study aims to investigate the effect of laboratory-developed SAW fluxes on the electrochemical corrosion behavior of SAW weldments in different environments. Electrochemical corrosion behavior of weld specimens in different environments was performed using Linear Sweep Voltammetry. Different mediums such as seawater and sodium thiosulphate solution (10−2Mol/l, pH = 3, and 10−3Mol/l, pH = 5) were taken for the corrosion study. The microstructure of the weld specimen reveals the presence of acicular ferrite structure. F3RA and F19RA weld specimen shows a higher corrosion rate in seawater and sodium thiosulphate medium (pH = 3 or 5).