Textures and properties developed in grain-oriented 0.004 in 3% silicon-iron strip

Either the Goss (110) [011] texture or the cube (100) [001] texture may be developed in 0-004 in 3% silicon-iron strip. The texture that develops on secondary recrystallization is dependent on the purity of the furnace atmosphere and the temperature at which the final heat treatment is carried out. A simple theoretical treatment of the energy-balance equation of a growing grain in a primary recrystallization matrix shows how the experimental results can be explained on the basis of surface-energy differences between grains of different orientations, and the dependence of these differences on the heat-treatment conditions. It is predicted that a grain with six or more sides can undergo unlimited growth, provided that the difference in surface energy (¿m ¿ ¿g) between the growing grain (¿g) and the matrix grains (¿m) is greater than about 70 ergs/cm2. Power-loss measurements on both cube-texture and Goss-textured materials are presented, and a comparison is made with commercial grain-oriented material. Experimental results from measurements on single-crystal picture frames are used to predict how far it should be possible to lower this loss. Magnetostrictive measurements on Goss- and cube-textured strip show no appreciable difference in the magnetostrictive behaviour of the two materials, and a general discussion on magnetostriction in terms of domain-wall movements is given. It is concluded that an increase in the degree of grain orientation will bring about a reduction in power loss and magnetostriction.