O is a harmful element in steel. It naturally enters the steel during the steelmaking process. Although manganese, silicon, iron and aluminum are added for deoxidation at the end of steelmaking, it is impossible to remove. During the solidification of molten steel, the reaction of oxygen and carbon in the solution generates carbon monoxide, which can cause bubbles. Oxygen is mainly present in the form of inclusions such as FeO, MnO, SiO2, and Al2O3 in the steel, which lowers the strength and plasticity of the steel. In particular, it has a serious impact on fatigue strength, impact toughness, and the like.
Oxygen will increase the iron loss in the silicon steel, the magnetic permeability and the magnetic induction strength are weakened, and the magnetic aging effect is intensified.