A device or an accessory may include a near-field communications antenna and a soft magnetic ring concentric with the near-field communications antenna. The device or accessory may further include at least one wireless charging coil concentric with the near-field communications antenna, a rectifier coupled to the at least one wireless charging coil, and a battery configured to receive a rectified voltage from the rectifier. The soft magnetic ring may be used to shunt magnetic flux from one or more nearby magnets in external electronic devices to prevent the magnets from repelling each other. The soft magnetic ring may be attracted to a magnet in an external device to help align wireless charging coils in the two mated devices.

A device or an accessory may include a near-field communications antenna and a soft magnetic ring concentric with the near-field communications antenna. The device or accessory may further include at least one wireless charging coil concentric with the near-field communications antenna, a rectifier coupled to the at least one wireless charging coil, and a battery configured to receive a rectified voltage from the rectifier. The soft magnetic ring may be used to shunt magnetic flux from one or more nearby magnets in external electronic devices to prevent the magnets from repelling each other. The soft magnetic ring may be attracted to a magnet in an external device to help align wireless charging coils in the two mated devices.

The present invention relates to a grain-oriented electrical steel sheet including 2.0 to 6.0 wt % of Si, 0.01 wt % or less (excluding 0 wt %) of C, 0.01 wt % or less (excluding 0 wt %) of N, and 0.005 to 0.1 wt % of Co, and including a balance of Fe and other inevitable impurities.

The present invention relates to a grain-oriented electrical steel sheet including 2.0 to 6.0 wt % of Si, 0.01 wt % or less (excluding 0 wt %) of C, 0.01 wt % or less (excluding 0 wt %) of N, and 0.005 to 0.1 wt % of Co, and including a balance of Fe and other inevitable impurities.

Disclosed are a non-oriented electrical steel sheet and a manufacturing method therefore, the sheet ensuring excellent magnetic characteristics by having increased texture intensity of surface (100) through strict control of the content ratio of Si, Al and the like and through final annealing heat treatment in an inert gas atmosphere.

A method for manufacturing a non-oriented electrical steel sheet includes a step of performing hot rolling on a steel material having a predetermined chemical composition, a step of performing first cold rolling, a step of performing process annealing, a step of performing second cold rolling, and a step of performing any one or both of final annealing and stress relief annealing. A final pass of finish rolling is performed in a temperature range equal to or higher than an Ar1 temperature, the steel sheet is held for 2 hours or less in a temperature range lower than an Ac1 temperature in the final annealing, and the steel sheet is held for 1200 sec or more in a temperature range equal to or higher than 600° C. and lower than the Ac1 temperature in the stress relief annealing.

A non-oriented electrical steel sheet with an average magnetostriction λ.sub.p-p at 400 Hz and 1.0 T of not more than 4.5×10.sup.−6, and area ratio of recrystallized grains at a section in rolling direction of steel sheet of 40 to 95% and an average grain size of 10 to 40 μm is obtained by subjecting a steel slab containing, in mass %, C: not more than 0.005%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, Al: not more than 3.0%, P: not more than 0.20%, S: not more than 0.005%, N: not more than 0.005%, Ti: not more than 0.003%, V: not more than 0.005% and Nb: not more than 0.005% and satisfying Si—2Al—Mn≥0 to hot rolling, hot-band annealing, cold rolling and finish annealing under adequate cold rolling and finish annealing conditions, and a motor core is manufactured by such a steel sheet.

A non-oriented electrical steel sheet with an average magnetostriction λ.sub.p-p at 400 Hz and 1.0 T of not more than 4.5×10.sup.−6, and area ratio of recrystallized grains at a section in rolling direction of steel sheet of 40 to 95% and an average grain size of 10 to 40 μm is obtained by subjecting a steel slab containing, in mass %, C: not more than 0.005%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, Al: not more than 3.0%, P: not more than 0.20%, S: not more than 0.005%, N: not more than 0.005%, Ti: not more than 0.003%, V: not more than 0.005% and Nb: not more than 0.005% and satisfying Si—2Al—Mn≥0 to hot rolling, hot-band annealing, cold rolling and finish annealing under adequate cold rolling and finish annealing conditions, and a motor core is manufactured by such a steel sheet.

A silicon oxide-coated soft magnetic powder, in which the ratio of a volume-based cumulative 50% particle diameter D50 (HE) according to a dry laser diffraction particle size distribution analysis to the same particle diameter D50 (MT) according to a wet laser diffraction particle size distribution analysis is 0.7 or more, and a coverage ratio R defined by R=Si×100/(Si+M) (Si and M are molar fractions of Si and elements constituting the soft magnetic powder) is 70% or more is obtained by subjecting a slurry containing a soft magnetic powder containing 20 mass % or more of iron and a hydrolysate of a silicon alkoxide to a dispersion treatment when the surface of the soft magnetic powder is coated with the hydrolysate in a mixed solvent of water and an organic substance. The powder has good insulation/dispersibility properties and a high filling factor during molding.

Provided are a motor core having excellent fatigue resistance and a method of manufacturing the motor core at a low cost. The motor core that is an electrical-steel-sheet-stacked body has an outer peripheral surface in which an appearance ratio of recrystallized grains with a grain size of 15 μm or less is 70% or more of a sheet thickness of the motor core.