Abstract: In order to improve the quality of non oriented electrical steel and reduce the production cost, the evolution law of inclusions, the changes of magnetic properties and surface quality of finished products in RH refining process under different molten steel circulation flow rates were analyzed. The results showed that the change of RH refining process had no obvious effect on the composition of inclusions in molten steel, the number of inclusions in hot rolled samples and the magnetic properties of finished products, but had a negative correlation effect on the surface quality. The larger the circulating flow rate of molten steel was, the lower the inclusion degradation rate was. The equivalent area of inclusions in molten steel, especially the larger inclusions above 5 μm, was negatively related to the circulating flow rate of molten steel. The inclusions (including the second phase precipitates) in hot rolled samples were mainly the second phase precipitates AlN and MnS, and a small amount of oxide inclusions. The amount of inclusions had no correlation with RH refining process. On the premise of ensuring the quality to meet the requirements, the circulation flow of molten steel in RH process can be adjusted appropriately to reduce the production cost.

Key words: electrical steel, inclusion, precipitate, magnetic property, RH refining