Studying On Evolution Of Texture During Annealing And Punching Process In High Silicon Steel Thin Sheets

High silicon steel containing about 6.5wt.%Si is an ideal material for high frequency transformers and high speed motor and high frequency reactor with excellent soft magnetic properties,such as improved electrical resistivity,low magnctocrystallinc anisotropy,and near-zero magnetostriction.The magnetic properties of high silicon steel can be sensitive to recrystallization texture.For the high silicon steel,after cold rolling and annealing it prone to form strong y texture which is harmful for the magnetic properties,while It is hard to form a texture of λ texture which is the ideal texture component.However,the formation and evolution of λ texture is not clear.As the iron core material,high silicon steel thin strip must be processed into the shape and size required.However,punching and cutting researchs about high silicon steel thin strip arc rarely reported result from it’s high hard brittleness.In present study,high silicon steel thin sheet with thickness of 0.30mm,0.20mm and 0.15mm was successfully produced by conventional method,including hot rolling,cold rolling and final annealing.Furthermore,the formation and evolution of the λ texture in the process of recrystallization was analyzed in near situ by a combination of EBSD and high vacuum annealing.What’s more,analysising the different effect of microstructure and magnetic properties of high silicon steel cutting by EDM,laser cutting and punching processing.Through the study,we get the following conclusions:(1)The nucleation locations of the λ nucleation are mainly of two types,the shear bands of {112}<110>and {144}<432>and the grain boundaries of {112}<110>.The λ nucleus in the low energy storage deformation grains is more likely to grow.Because of ｛112}<110>belonging to low energy storage deformation matrix,and the deformation {144}<432>stoge much energy.The λ grain nucleus in the shear band and the grain boundary of {112}<110>grain is easy to has the anvantage of grain size.And evolved into the dominant texture component.(2)In appropriate conditions,high silicon steel sheet can be machined by punching.The punching processes of high silicon steel can be improved significantly with the decrease of grain size or the increase of punching temperature.Stress relieve annealing can eliminate the damange from punching which reduce the magnetic induction and magnetic permeability.What’s more,the damage of magnetic properties caused by punching processing can be reduced with the increase of temperature.(3)Contrast the influence of magnetic properties of high silicon steel sheet cutting by punching,laser cutting and EDM:EDM has the minimal damage,while laser cutting has the maximum damnge.The damage from EDM increase with the increase of the grain size.Compared with the magnetic induction,the magnetic permeability is influenced by the cutting method.The damange caused by cutting can be eliminate after the stress relieve annealing.