Influence of Microstructure and Geometric Discontinuity Introduced by Weld Reinforcement Height on the Corrosion Behavior of SA106B Welded Joints in a Flowing Solution

Abstract

The corrosion of welded joints creates widespread issues for the ocean engineering, petrochemical, and nuclear power industries. Geometric discontinuity of the weld reinforcement height plays an important role in weld corrosion, but the mechanism is still unclear. The corrosion behavior of flat and convex SA106B welded joints is investigated at different flow velocities by experiments and simulation. The damage components of the material and geometric discontinuity are quantified. Electrochemical measurements, morphology observations, and flow field simulations are conducted. The results show that the corrosion of the welded joints is influenced by mass transfer and galvanic corrosion. The corrosion of the welded joints is aggravated by geometric discontinuity and increased flow velocity. The damage component introduced by the material of the welded joint decreases with increasing flow velocity, and the maximum value is 91.56% at 0.5 m/s. The damage component introduced by the geometry of the weld reinforcement height increases with increasing flow velocity, reaching up to 45.77% at 6.9 m/s. The corrosion mechanism is also discussed.