Cold rolled non-oriented electrical steel composition

- Jul 15, 2019-

Electrical steel, also known as silicon steel sheet, has a history of more than 100 years. Cold-rolled electrical steel consists of oriented electrical steel and non-oriented electrical steel. Non-oriented electrical steel is mainly used as large and medium-sized motors, generators, and household motors and micro-motors. Cores such as ballasts and small transformers. The main magnetic properties of non-oriented electrical steels are low specific loss and high magnetic polarization. Low ratio total loss can save a lot of power and extend the working hours of the motor. The high magnetic polarization means that the magnetization ability is strong, the excitation current of the iron core is lowered, and the total loss and the copper loss are both lowered. The total loss and magnetic polarization are not only related to chemical composition, but also related to its internal organization. In order to understand the characteristics of non-oriented electrical steel in order to better guide production and improve product quality, the author comprehensively studied the relationship between the composition, structure and properties of cold rolled non-oriented electrical steel grades W600, W800, W1300, with a view to Provide reference for the subsequent production of cold rolled non-oriented electrical steel.

Cold rolled non-oriented electrical steel grades refer to W600, W800, W1300, and the thickness of the steel plate is 0.5mm. It can be seen from the statistical average of the three chemical compositions that the three grades of electrical steel are ultra-low carbon non-oriented electrical steels. The main difference between the three components is that the silicon and aluminum contents are different.

In non-oriented electrical steel, silicon has the effect of increasing the resistivity and reducing the total loss, but silicon is a non-magnetic element, silicon reduces the saturation magnetization, and correspondingly reduces the magnetic polarization, which is detrimental to magnetic properties. At the same time, too high silicon content will make the steel brittle, which makes the cold processing difficult. Therefore, the upper limit of the silicon content of the cold-rolled electrical steel is generally controlled at about 3.0%. The role of aluminum is similar to that of silicon. Aluminum can reduce the γ phase region, coarsen the grain, increase the resistivity, reduce the magnetic anisotropy, reduce the total loss, and also reduce the magnetic polarization, while the strength and hardness of the steel The impact is not as obvious as silicon. Both silicon and aluminum control the mechanical and magnetic properties of non-oriented electrical steel by controlling grain size or texture.