LAUSR

The process of electrical power transmission from power generation stations to residential, industrial and commercial areas, involves the use of grain oriented silicon steels as a soft magnetic material in transformer cores. Compared to some other magnetic materials these alloys are not only economic, but also yield a high magnetic flux under an applied field of 800 A/m (B800). These properties are related to the presence of Goss grains in the alloy, which have a crystallographic orientation having the <100> direction parallel to the rolling direction (RD) and {110} plane parallel to the rolling plane (ND) of the steel sheets. These are then arranged in laminates in the transformer core. It has been demonstrated that <100> is the easiest magnetization direction for a bcc lattice.4,5) Therefore having a high density of Goss grains serves to increase the magnetic anisotropy of the steel through altering the shape of the hysteresis loop, and hence, reduces hysteresis losses. However, in industrially processed polycrystalline steel sheets grains are often deviated from the ideal Goss {110}<100> orientation. In a given grain the angular distance from the ideal Goss orientation is called the deviation angle, which has been used to describe the sharpness of the Goss texture in the material.6–8) Effect of Heating Rate and Annealing Temperature on Secondary Recrystallization of Goss Grains in a Grain Orientated Silicon Steel