Magnetic Properties and Recrystallization Texture Evolutions of Phosphorus-bearing Non-oriented Electrical Steel Sheets

Abstract

The effect of phosphorus (P) on magnetic properties and also on recrystallization texture of non-oriented electrical steel sheets has been investigated to develop core materials with low core loss and high permeability. Specimens containing different amounts of P were cold-rolled to various thicknesses, i.e. with various cold-rolling reductions, and annealed for recrystallization and grain growth. Magnetic induction of the steel with a large amount of P was higher than that of the steel with a small amount of P. Moreover, magnetic induction of the steel with a large amount of P slightly decreased with reduction of sheet thickness, i.e. with an increase in cold-rolling reduction, whereas magnetic induction of the steel with a small amount of P dramatically decreased. The most effective way to reduce core loss was to reduce thickness of electrical steel sheets. Therefore, P-bearing thin gauge non-oriented electrical steel sheets achieved low core loss and high permeability. The typical magnetic properties of P-bearing non-oriented electrical steel sheets with a thickness of 0.27 mm were 16.6 W/kg in W10/400 and 1.73 T in B50. These excellent magnetic properties were provided by the recrystallization texture control by P. {111}͗112͘ component in recrystallization texture, which deteriorates magnetic properties of electrical steel sheets, was suppressed during recrystallization. Furthermore, {j 1 , F, j 2 }ϭ{25°, 10-15°, 45°} component significantly developed at the expense of {111}͗112͘ component during grain growth. P segregation at initial grain boundaries would be responsible for this texture evolution. Accordingly, P would greatly contribute to the improvement of magnetic properties of nonoriented electrical steel sheets through the recrystallization texture control.

Effect of Ag Content on the Microstructure and Magnetic Properties of Grain-oriented Silicon Steels

“…31) There are also some ribbon-like grains in decarburized bands with Ag contents of 0.003 wt% and 0.005 wt%. Tanaka et al 32) reported that impurity atoms segregate at grain boundaries could result in that the coincidence site lattice (CSL) boundaries have lower grain boundary energies and higher migration mobility than general grain boundaries. Thus, during decarburizing, the abnormal growth of ribbon-like grains in decarburized bands with Ag contents of 0.003 wt% and 0.005 wt% is likely to be a combination of grains having CSL boundaries with adjacent grains.…”

Effect of copper precipitates on the stability of microstructures and magnetic properties of non-oriented electrical steels

“…Tanaka et al [12] reported that the coincidence site lattice (CSL) boundaries have usually lower grain boundary energies and higher migration mobility than general grain boundaries in non-oriented electrical steels, especially when impurity atoms segregate at grain boundaries. Gomes et al [13] reported that the surface grains with ‹100›// ND orientation tend to rotate 15°along the Euler angle Φ to match {115} fiber which exhibits a Σ3 CSL relationship with both {110} and {111} fibers.…”

Effect of Sn Addition on Evolution of Primary Recrystallization Texture in 3% Si Steel

“…The effect of the addition of segregation atoms other than Sn, for example, Sb [6][7][8][9] and P, [10][11][12][13][14] on the recrystallization texture has also been discussed. Tanaka et al 14) suggested that Σ9 coincidence site lattice (CSL) boundaries had priority in grain boundary migration under the solute drag effect of P, and this effect resulted in selective grain growth of the {φ 1 , Φ, φ 2 } = {25°, 10-15°, 45°} component; φ 1 , Φ, φ 2 are Bunge Euler angles representing crystal orientation. However, the behavior of grain boundary migration during grain growth under the existence of segregation atoms is still unclear.…”