Soft magnetic steel material and manufacturing method thereof and soft magnetic part obtained from soft magnetic steel material

摘要

An object of the present invention to provide a soft magnetic steel that improves the magnetic properties, that is, the soft magnetic properties, the cold forgeability, and the magnetic aging characteristics without adding a large amount of alloy elements. The present invention is directed to a soft magnetic steel, including C, Mn, P, S, Al, and N in each predetermined amount, in which an area ratio of carbides and carbonitrides that have a thickness of less than 0.4 µm is 0. 20 area% or less, and an area ratio M of carbides and carbonitrides that have a thickness of 0.4 µm or more in terms of percentage satisfies a relationship represented by the formula (1) below: F = M ˆ’ 20 × C 0 where [C] means a C content in the steel in percentage by mass.