Study On The Effects Of Different Cold-rolling Reduction On The Texture Development Of Grain-oriented Silicon Steel

Grain-oriented silicon steel is widely used as iron core materials of transformer and the best material in silicon steel.Its finished product needs for the Goss texture with large grain size and exact orientation,so that manufacture of grain-oriented silicon steel needs for highly advanced equipment and technology.For the purpose of researching on the effects of different cold-rolling reduction on the texture development of grain-oriented silicon steel,this paper mainly studied on the cold-rolling process in the manufacture of grain-oriented silicon steel using normalized silicon band treated by 6 different hot-rolling technology.In this experiment,metallographic observation,XRD and EBSD are adopted as the main technologies to analyze the difference between the 6 different normalized silicon bands and the evolution of cold-rolling texture.The obtained results show as follows:(1)The main microstructure of normalized silicon bands is ferrite,but a little pearite distributed along the ferrite grain boundary.The grain size of ferrite from the surface to the center layer is uneven.The grains at surface and subsurface are small,while at center layer are large and long.There is some difference in grain size between the 6 different normalized silicon bands.With the increase of cold-rolling reduction,the grains were compressed to more longer and lighter.And shear band appeared when the silicon bands were cold-rolled after certain reduction.(2)In the normalized silicon bands,the texture at surface and subsurface is weak,but at center layer is very sharp.At center layer,there is a lot of a texture with large and long grain size.With the increase of cold-rolling reduction,the volume fraction of a texture increased.The volume fraction of a texture at surface and subsurface increased fast,while at center layer increased slowly.When rolled to 0.29-0.40mm,the volume fraction of a texture stop increasing.The distribution and volume fraction of ? texture in 6 different normalized silicon bands are different.With the increase of cold-rolling reduction,the volume fraction of y texture increased.The volume fraction of y texture at surface and subsurface increased fast,while at center layer increased slowly.When rolled to 0.26-0.40mm,the volume fraction of y texture stop increasing.After rolled to 0.40mm,the volume fraction of y texture complies with the following rules:surface>subsurface>center layer.(3)The main cold-rolling texture is a texture and y texture.The main a texture is{001}<110>and {112}<110>.The main ? texture is {111}<110>and {111}<112>.In the normalized silicon band,the volume fraction of {001}<110>is higher than{112}<110>,but after cold-rolling,the speed of {112}<110>increase more fast than{001}<110>,so in cold-rolling silicon band,the volume fraction of {112}<110>is higher than {001}<110>.In the normalized silicon band,the volume fraction of{111}<112>is higher than {111}<110>,but after cold-rolling,the speed of{111}<110>increase more fast than {111}<112>,so in cold-rolling silicon band,the volume fraction of {111 }<110>is higher than {111 }<112>.(4)In normalized silicon bands,Goss texture mainly locate at surface and subsurface.The size of Goss grain is small.At the beginning of cold-rolling,the volume fraction of Goss texture decreased with the increase of cold-rolling reduction.When rolled to 0.70mm,the volume fraction of Goss texture stop decrease and remain stable in the range 1.4%-1.6%.In cold-rolling silicon band,{111}<112>texture distributes around Goss texture.