Abstract: The corrosion behavior of 50W800 non-oriented electrical annealed steel under neutral salt spray condition was studied, and the causes of corrosion were analyzed.Metallographic microscope, scanning electron microscope (SEM) and energy spectrum analysis (EDS) were used to analyze the microstructure of the annealed samples, and the macroscopic and microscopic corrosion morphology of the 50W800 annealed samples of non-oriented electrical steel were analyzed to determine the corrosion reasons of the annealed plates.The microstructure analysis results showed that the metallographic structure of the 50W800 annealed sample of the nonoriented electrical steel is equiaxed crystal ferrite structure. The typical inclusions in the 50W800 annealed sample of the nonoriented electrical steel include AlN inclusions, Al2O3 inclusions, Al2O3-MnS inclusions and MgO-Al2O3-MnS inclusions.The results of corrosion behavior process showed that there are three kinds of rust spots with different morphology in the corrosion process of 50W800 test plate of non-oriented electrical steel, and the change process of rust spots with different morphology is different within 60 minutes of salt spray box corrosion.According to the analysis of corrosion process and cause of 50W800 test sample of non-oriented electrical steel, the main reason for corrosion of sample is the change of corrosion morphology caused by inclusions Al2O3, Al2O3-MnS and MgO-Al2O3-MnS.Moreover, the corrosion area caused by Al2O3-Mns inclusions above 10μm increases with the increase of corrosion time.

Key words: non-oriented electrical steel, neutral salt spray, inclusions