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In this paper, the magnetic properties of non-oriented (NO) and grain-oriented (GO) silicon steels with dc-biased induction are measured and analyzed within the wide range of 20–1000 Hz, 0–1.9 T. While by the physical method, we found that all the ac-, dc-, and dc-biased fields do not influence the electrical resistivity of silicon steel, and hysteresis loss is mainly responsible for the iron loss increase when dc-biased induction exists. With the frequency and ac induction going up, the effect of dc-biased induction on iron loss will become weak. Compared with NO steel, iron loss of GO steel is more sensitive to dc-biased induction. The validation shows that existing iron loss models which claim to consider dc-biased magnetic induction are not satisfactory up to now when applied in the wide range of dc-biased induction, ac induction, and frequency. [ABSTRACT FROM AUTHOR]

SUMMARY The accurate magnetic properties of electrical steel sheets are important for the development of high-efficiency electromagnetic devices. In particular, the H-coil method is a useful technique for accurately measuring magnetic field strength in a single sheet tester. Therefore, we developed a tester for magnetic field properties using the H-coil method, referred to as the stress load type single sheet tester (S-SST), and a problem was found in iron loss measurement at a high flux density of 1.6 T or more. In this paper, it is shown that the cause of this problem is the phase difference between the induced voltage in the H-coil and the B-coil. Because the phase difference makes the B-H loop slightly twisted near the tip point, the iron losses are evaluated low. Thus, we propose a method of determining the phase correction values. These values are measured in the absence of a specimen in the S-SST measurement system, and the phase correction method for induced voltage in a coil is investigated. Finally, ideal results for the correction of iron loss in nonoriented electrical steel sheets are shown. The proposed method is effective for the calibration of a single sheet tester using the H-coil method. [ABSTRACT FROM AUTHOR]

The influence of stresses on the magnetic properties of nonoriented electrical steels was studied. The dependence of iron loss on compressive stress was affected by grain size. The magnetic polarization J in strong magnetic fields such as 5000 and 10,000 A/m increased due to compressive stresses and decreased due to tensile stresses in samples with low Si content. Using Kerr-effect domain observation, it was found that the reduction in J caused by tensile stresses was attributable to residual striped domains. Magnetostriction measurements in strong magnetic fields indicated that the increase in J under compressive stresses originated from the Villari effect (inverse magnetostrictive effect) due to negative magnetostriction in low-Si materials. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(4): 10-18, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22320 [ABSTRACT FROM AUTHOR]

The influence of the tile angle of the [001] out of crystal surface \beta on iron loss improvement of 3 % Si steel single crystals was investigated. This iron loss improvement was caused by tensile stress effect of TiN coating and domain refinement. When \beta angle was less than 3 degrees, both eddy current loss and hysteresis loss decrease. Extremely low iron loss was obtained, when \beta angle equal to about 2 degrees. On the other hand, when \beta angle is more than 3 degrees, the hysteresis loss increased though the eddy current loss decreased by TiN coating. As a result, change in iron loss was small after TiN coating and domain refining. Therefore, it was clarified that the iron loss improving methods, such as domain refining and ultra-high tension coating, were effective especially in grain oriented electrical steel whose \beta angle is less than 3 degrees. [ABSTRACT FROM PUBLISHER]