Study On Magnetic Properties And Texture Of High Grade Non-oriented Silicon Steel With Rare Earth Addition

Lower iron loss,higher magnetic induction,smaller magnetostriction,and higher processability are necessary for the high grade non-oriented silicon steel.Grain size and texture are the key to the magnetic properties of non-oriented silicon steel.Higher cleanliness,appropriate grain size and more favorable recrystallization texture is requested for the high-grade non-oriented silicon steel.Non-oriented silicon steel contains a large number of inclusions such as oxides and sulfides with different shapes and sizes ranging from 0.1 to 5 ?m.The small-sized inclusions in these inclusions can effectively pin the magnetic domain walls,while pinning grain boundary movement affects the crystal grain grow and deteriorates magnetic properties.Since rare earth elements are easily combined with oxygen and sulfur elements in steel to enhance the desulfurization and deoxidation effect,they can improve the cleanliness of non-oriented silicon steel molten steel and chang the shape of inclusions,which is conducive to grain growth and optimization of magnetic properties.Texture is another important factor affecting the properties of non-oriented silicon steel.How do rare earth element doping affect the texture characteristics and magnetic properties is an important issue for optimizing non-oriented silicon steel.This paper studied the influence of RE element on the recrystallization texture and magnetic properties,and revealed the RE element effect mechanism in the recrystallization nucleation and growth mechanism was revealed.Based on the iron loss separation model,an iron loss calculation model considering recrystallization texture and grain size effect is proposed to provide a control optimization path for the magnetic properties of high-grade non-oriented silicon steel.The main conclusions are as follows:(1)The non-uniform gradient characteristics along the thickness direction of the recrystallized structure and texture in the non-oriented silicon steel increase first and then decrease witn the addition of the rare earth content,which is due to the effect of the addition of RE element on the texture and precipitation phase characteristics before cold rolling.The RE element of 0.005?0.045%significantly increases the recrystallized grain size,enhances the favorable ? and a texture components in the central layer,and weakens the unfavorable y texture components,leading to optimization of magnetic properties.When the addition amount of RE is 0.085%,the y texture under each thickness layer is marked enhanced,and the ? and a texture are weakened,leading to the deterioration of magnetic properties;(2)The recrystallized texture of RE-doped non-oriented silicon steel weakens with the increase of grain size.0.005?0.045%RE element can effectively maintain the favorable texture strength such as ?,? and ?,and reduce unfavorable ? texture strength.The iron loss of non-oriented silicon steel shows nonlinear change with the increase of grain size.The optimum iron loss has the optimal value of grain size.It depends on the quantitative relationship among grain size and hysteresis loss and abnormal loss.RE element doping induces changes in texture and inclusion characteristics that cause iron loss to change non-linearly with RE element content in non-oriented silicon steel.0.005 to 0.045%RE element addition can effectively reduce iron loss and reduce the optimal grain size;(3)Based on the iron loss separation mechanism,build a calculation model of iron loss considering the influence of grain size and texture both on hysteresis loss and abnormal loss.The texture and iron loss properties of RE-doped oriented silicon steel during the recrystallization grain growth process are used to verify the model in this paper,which provides a control optimization path for the magnetic properties of high-grade non-oriented silicon steel.Based on the non-linear influence of RE element on magnetic properties,an improved idea of iron loss calculation model for inclusion characteristics was proposed.