Texture—Electrical-Property Correlations in Oriented Silicon Steel

Grain-by-grain measurements of crystallographic orientations have been made to study the relationship between texture and electrical properties of oriented silicon steel. An etch was used to produce a faceted surface of (100), cube, planes thus making each grain brightly reflective in three perpendicular directions. An optical goniometer was used to determine the crystallographic orientation of each grain. Orientation is defined in terms of three angles as follows: (1) α-the divergence in the plane of the sheet of the [001] direction from the rolling direction, (2) β-vertical tilt of the [001] direction from the rolling direction, (3) γ-the rotation of the (110) plane about the direction of magnetization. Statistical methods were used to calculate the degree of texture in terms of the spread or distribution of these angles and to correlate the distribution with electrical properties. A strong correlation was found between α and permeability at 10 H. About 75% of the variation in permeability at 10 H could be accounted for through variations in α. Only about 55% of the variation in core loss could be accounted for through variations in α. Correlation of β with permeability was not significant. The angle γ should not appreciably affect electrical properties and no correlation was found.