Effect of Oxide Inclusions on the Magnetic Properties of Non‐Oriented Electrical Steel

A plant experiment is conducted to study the effect of oxide inclusions on the magnetic properties of non‐oriented electrical steel. The morphology, size, and composition of oxide inclusions are investigated by an automated scanning electron microscope. In the liquid steel, the increase of the content of CaO in oxide inclusions promotes the inclusion size and decreases the width of the size distribution. Besides, the viscosity of oxide inclusions plays a key role on the deformation during the hot rolling process at 1000 °C. When the viscosity of inclusions is larger than that of the steel matrix, the oxide inclusions are nearly undeformed. While when the viscosity of inclusions is lower than that of the steel matrix, the inclusions are deformed into chain‐like shape and the elongation ratio increases with the decreasing of viscosity. Additionally, deformed oxide inclusions perform a greater pinning force on the moving of grain boundaries, which is verified by the measured results of the grain size. Thus, in terms of increasing the magnetic properties, the viscosity of oxide inclusions shall be controlled to larger than that of the steel matrix by adjusting the inclusion composition.