Study On Evolution Of Recrystallization Texture In Electrical Pure Iron

Electrical steel is mainly used for various types of electric motors and transformer core. Its application amount is largest among soft magnetic materials. Low carbon low silicon non-oriented electrical steel is a kind of electrical steel with silicon content less than1.0%. Because of its advantages in high magnetic induction and low cost, the application amount of low carbon low silicon non-oriented electrical steel is exceeding60percent of that of electrical steel. The magnetic properties of low-carbon low-silicon non-oriented electrical steel are very sensitive to recrystallization texture, but the texture optimization does not always have a perfect solution. To simplify the problem, the paper selected electrical pure iron as a model material to study the texture optimization problem of low-carbon low-silicon non-oriented electrical steel.Based on experiments, this paper studied the effects of hot-rolling, normalizing, and the cold rolling process on the cold rolling deformation structure and texture and the recrystallization texture of electrical pure iron, using X-ray diffraction and electron backscatter technology. The obtained results show as follows:The effect of hot rolling texture on the final recrystallization texture is significant. Four kinds of hot rolled plates with different hot rolling textures, having identical grain sizes, were obtained by controlling hot rolling process. The cold rolling texture of four kinds of cold-rolled thin sheets are similar, rolled by the same process, however, recrystallization texture of four kinds of thin sheets after annealing at850℃for5min are different. The density of Goss texture in recrystallization texture of electrical pure iron thin sheets with1000℃hot rolling process is largest. It is mainly because the strongest Goss texture is formed in the hot rolled plates with this process, conditions, resulting in the strongest Goss texture in the final annealed sheets due to the heredity of texture.The effect of grain size in normalized hot rolled plates on the cold rolling texture and recrystallized texture of pure iron thin sheet cold rolled with65%reduction ratio is significant. With the increase of grain size in normalized hot rolled plates, the intensities of cold rolling texture and the lengths and densities of shear band increase. After annealing, recrystallized texture is mainly composed of Goss and its intensities increase with increase of grain size in normalized hot rolled plates. According to the analysis about the microstructure and micro-texture of recrystallization process, oriented nucleation of Goss orientation in numerous of shear bands is the main mechanism to explain the formation of strong Goss texture.Two kinds of cold rolling texture produced by symmetric and asymmetric rolling are both composed of α, γ fiber and τ fibers with peak at{554}<225>. The cold rolling texture in symmetric rolled thin sheet is a fibers with peak at{114}<110>, and in asymmetric rolled thin sheet is a fibers with peak at{223}<110>. The density of shear band in cold rolled thin sheet is higher in asymmetric rolling versus that in symmetric rolling. The rolling modes have an obvious effect on recrystallization texture, asymmetric rolling tends to increase the intensities of Goss texture and decrease that of a, y texture.Cold rolling texture and recrystallization texture are influenced by cold rolling reduction ratio. As cold rolling reduction ratio increases, the intensities of cold rolling texture increase,{223}<110> component increases obviously, y fibers slightly improve, and the width of deformed grains and the length of in-grain shear bands decreased. The intensties of Goss along η fibers first increase then decrease with the variation of cold rolling reduction ratio and the trend is slight. The intensities of y fibers gradually improve and the trend is obvious.