The Corrosion Resistance of Magnesium Alloy Spot Welding Joint

In order to improve the corrosion resistance of magnesium alloy welding joints,a DN-100 stationary spot welder was used to weld AZ31B magnesium alloy.The best welding parameters of spot weld were achieved by tensile test and metallographic observation,and the corrosion resistance testing for the spot weld was performed.According to the microstructure observation of the parent metal and weld corrosion samples in 3.5% NaCl solution at different times,the results showed that both joint and parent metal didn′t have good corrosion resistance.After electroless plating on the surface of welding joint and base metal samples for galvanic corrosion test,the polarization curve analysis indicated that through chemical plating the corrosion resistance of welding samples improved.Chemical coating layer within the range of -0.2~0.5 V(SCE) corrosion potential the current changed little,showing obvious passivation characteristics.