Composite magnetic member, method of producing ferromagnetic portion of same, and method of forming non-magnetic portion of same
US6255005A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Jul 22, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12986
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
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%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.