PRESSED POWDER FORMED BODY PRODUCTION METHOD

摘要

A compact is provided. When the compact is used for a magnetic core, a magnetic path cross section has a cross-sectional perimeter of more than 20 mm, and at least part of a surface of the compact is covered with an iron-based oxide film having an average thickness of 0.5 µm or more and 10.0 µm or less. Letting the proportion of the surface area of the compact to the volume of the compact be surface area/volume, the content of Fe 3 O 4 present in the iron-based oxide film with respect to 100% by volume of the compact satisfies any one of (1) to (3): (1) less than 0.085% by volume when the (surface area/volume) is 0.40 mm -1 or less, (2) 0.12% or less by volume when the (surface area/volume) is more than 0.40 mm -1 and 0.60 mm -1 or less, and (3) 0.15% or less by volume when the (surface area/volume) is more than 0.60 mm -1 .