Corrosion Behavior and Mechanism of Weld Joints of Q370qENH Weathering Steel After Submerged Arc Welding
In order to study the corrosion mechanism of welded material of Q370qENH weathering steel by submerged arc welding(SAW),experiments were conducted on immersion corrosion and electrochemical corrosion of Q370qENH substrate samples and weld seam samples after SAW process,and the morphology and composition of the surface rust formed after immersion corrosion were characterized.The results indicate that the corrosion resistance of the weld seam of Q370qENH by SAW process is lower than the substrate,and its electrochemical impedance is 38%of the substrate.The reason for the lower corrosion resistance of weld seam than the substrate and the formation mechanism of surface rust were all analyzed.The research results can provide scientific and theoretical basis for the safety assessment for the service of weathering steel in engineering projects of steel bridges for high-speed railway,as well as its following maintenance.