Corrosion Inhibition Of Four Magnesium Alloy Corrosion Inhibitors In 3.5%NaCl Solution

Magnesium alloys have many excellent properties,such as low density,high strength-to-weight ratio,good property of resist pound et,so magnesium alloy has been used more and more widely in engineering.However,due to the active chemical nature of magnesium,magnesium alloys have poor corrosion resistance,which greatly limits the application of magnesium alloys in harsh working environments.With the development of anti-corrosion technology,many methods for protecting magnesium alloys have been proposed.Adding corrosion inhibitors is a simple,economical,and environmentally friendly anti-corrosion technology.Therefore,in this paper,the corrosion inhibition efficiency of magnesium alloy corrosion inhibitors was investigated by electrochemical corrosion test method and static weight loss test method,scanning electron microscope,energy spectrum analyzer,X-ray diffractometer,X-ray photoelectron spectrometer and Fourier transform infrared spectrometer were used to analyze the corrosion inhibition behaviors and inhibition mechanisms of four single corrosion inhibitors and compound corrosion inhibitors on magnesium alloys in 3.5%NaCl solution.The main results are as follows:(1)SLS is an anionic surfactant.The corrosion inhibition of magnesium alloy AZ91D and its corrosion inhibition efficiency will increase with the increase of its concentration.It is a dynamic physical adsorption process,and at the same time inhibits the anodic reaction and cathodic reaction of corrosion process.(2)Sodium metavanadate has corrosion inhibitory effect on AZ91D magnesium alloy.As the sodium metavanadate content increases,its corrosion inhibition effect on magnesium alloy increases first and then decreases.When the concentration is 0.1 mM,the corrosion inhibition is the strongest.Sodium metavanadate mainly inhibits the cathodic reaction of magnesium alloys and belongs to cathodic corrosion inhibitors.It is mainly through the reduction of vanadium on the magnesium alloy surface to generate vanadium oxide and forming an oxide film,thereby inhibiting the corrosion of magnesium alloys.(3)The corrosion inhibition of AZ31B magnesium alloy after compounded with sodium dodecylbenzene sulfonate(SDBS)and sodium silicate(SS)is much larger than that of single corrosion inhibitor.When the compounding scheme is 8 mM SDBS + 1 mM SS,it has the strongest corrosion inhibition effect on magnesium alloys.Studies have shown that the compounded corrosion inhibitor will participate in forming the film on the surface of the magnesium alloy together and improve the compactness of the film layer,thereby increasing the corrosion inhibition efficiency.