| 摘要 |
PURPOSE:To obtain a dust magnetic core, which has excellent magnetic characteristics in low and high frequency regions and excellent breakdown resisting strength even if the density of the dust core is low, by using atomized iron powder including specified S of 1-0.50% in a chemical composition. CONSTITUTION:The chemical compositions (wt%) of a dust core are as follows: C<=0.01; Si<=0.03; Mn<=0.25; P<0.020; Cu, Ni and Cr<=0.05, SIGMA[O]=0.25; SIGMA[N]=0.005; and S: 0.10-0.50%. Apparent density in composite density, 1.7-2.4g/cm<2>; thickness of a particle, 5-30mum; particle distribution for 42-mesh passage, 99% or more and that of 60-mesh passage, 85% or more, density of dust core in molding, 6.4g/cm<2> or more (desirably 6.50g/cm<2> or more) at compressibility of 4T/cm<2>; breakdown resisting strength in molding at 4T/cm<2>, 1.5kg/cm<2> or more; and grain size of ferrite, 6 or less (desirably 5 or less). The compressibility and the breakdown strength are the values when the mixture of Fe+0.75Zn-st is used.
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