A Study of Corrosion Inhibition Effect and Corrosion Inhibition Mechanism of Sodium Lignosulphonate on Mg Alloy AZ91D

The corrosion inhibition effect of sodium lignosulfonate (SLS) on magnesium alloy AZ91D in 3.5% NaCl solution was studied by electrochemical method and weight loss method. The morphology, film thickness and composition of corrosion product film were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that SLS could significantly inhibit the corrosion behavior of magnesium alloy AZ91D in 3.5% NaCl solution, and the corrosion inhibition rate increased with the increase of SLS content. Due to the agglomeration of SLS, the corrosion inhibition mechanism of magnesium alloy AZ91D in 3.5% NaCl solution containing different amounts of SLS was different; SLS did not participate in film formation, and the adsorption of magnesium alloy by SLS was physical adsorption.