Mitsumasa Kurosawa

Local magnetic properties in grain-oriented electrical steel measured by the modified needle probe method

Distribution of local magnetic properties in grain-oriented electrical steel was investigated using the needle probe method. The spatial nonuniformity of flux density was found to be affected by magentic poles on grain boundaries which mainly depend on the α angles between neighbouring grains and on the direction of grain boundaries.

Investigation on the domain refining effect in grain-oriented silicon steel

Conditions to maximize the domain refining effect were investigated using the plasma flame irradiation method. It was required to optimize the interval of plasma flame irradiated lines depending on the grain size of the sheet and to reduce the tilt angle of the sheet.

Investigation of secondary recrystallization kinetics in grain-oriented electrical steel using the ultrasonic interferometry

Measurements of the growth rate for the individual secondary recrystallized Goss grain in Fe–3%Si containing AlN and MnSe as grain growth inhibitors were made by the ultrasonic interferometry. It was found that the growth rates in the rolling direction for secondary recrystallized grains varied from 0.3 to 0.6 mm/min, and that the growth rate in the rolling direction is 1.2–1.9 times higher than that of the cross-rolling direction. The set of results were explained in terms of the concept of the “growth advantage” which is defined as the fraction of high-energy grain boundaries having the misorientation angles between 20° and 45° with respect to the specific secondary recrystallized grain in the primary recrystallized grains.