Study of Corrosion Resistance of Al-Mg and Re-Al-Mg Arc Spraying Coatings

Al-Mg and Re-Al-Mg coatings are prepared on Q235 steel surface by arc spraying technology.The corrosion resistance of Al-Mg and Re-Al-Mg coatings was studied respectively.The neutral salt spray test and electrochemical test have been used to study the corrosion resistance of the two coatings,and the microstructure of Al and Re-Al-Mg coatings before and after corrosion were analyzed by scanning electronic microscope.Then,the structure and anticorrosive mechanism are analyzed.The results show that there is a clear passive phenomenon of two kinds of coatings in the polarization process,and a layer of oxide film on the coating surface in the process of corrosion is generated,it is a physical shield which can delay the corrosion rate of coating,but the corrosion resistance performance of Re-Al-Mg coating is better than Al-Mg coating obviously,it's because by the rare earth elements added,it reduces the porosity of the coating,increasing the hardness of the coating and the bond strength with substrate,resulting in a coating with good corrosion resistance.