Finite element analysis of pitting pit on residual strength of magnesium alloy welded joint

This work analyzes the Tungsten Inert Gas (TIG)welded joint of AZ31 magnesium alloy and the pitting corrosion stress field at different depths under tensile load via the ANSYS finite element method. The strengths of the stress and strain fields inside the corrosion pit were substantially higher than the average strength level of the matrix. Therefore, under the influence of the applied load, the corrosion pit will fail first. Based on the study of pitting corrosion, a model was developed to explain how pitting corrosion cracks propagate in magnesium alloy welded joints. Finally, the variation of residual strength was revealed to study the corrosion dynamic mechanism of the joints.