Sughrue, Mion, Zinn, Macpeak & Seas, PLLC
Composite magnetic member, method of producing ferromagnetic portion of same, and method of forming non-magnetic portion of same
 Provided is a composite magnetic member made of a single material combining a ferromagnetic portion and a non-magnetic portion in which the ferromagnetic portion has better soft magnetism than conventional members and the non-magnetic portion has the same stable characteristic as conventional members. A method of producing the ferromagnetic portion of the member and a method of forming the non-magnetic portion are also provided. The composite magnetic member is made of an Fe--Cr--C-base alloy steel containing 0.1 to 5.0 weight % Al and has a ferromagnetic portion with a maximum magnetic permeability of not less than 400 and a non-magnetic portion with a magnetic permeability of not more than 2. In this member the number of carbides with a grain size of not less than 0.1 .mu.m is regulated to not more than 50 in an area of 100 .mu.m.sup.2 and the proportion of the number of carbides with a grain size of not less than 1.0 .mu.m to the number of all carbides is controlled to not less than 15%. 
Hitachi Metals, Ltd.
C Y C Y C H C Y C C Y Y Y
C21D Y10T C21D Y10S C21D H01F C22C Y10T C22C C22C Y10S Y10T Y10T
additional additional inventional additional additional inventional inventional additional inventional inventional additional additional additional
Hideya Shin-ichiro Tsutomu
Yamada Yokoyama Inui