The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1981
Filed:
Sep. 26, 1978
Rudolf Fichte, Nuremberg, DE;
Hans-Joachim Retelsdorf, Weiherhof, DE;
Richard Jervis, Stolberg, DE;
Gunter Radel, Nuremberg, DE;
GfE Gesellschaft fur Elektrometallurgie mit beschrankter Haftung, Dusseldorf, DE;
Abstract
A workpiece of alloy steel is produced by sintering under a nonoxidizing atmosphere a mass of malleable-iron powder admixed with a comminuted complex ferroalloy. The latter, obtained from a molten mixture of several simple high-carbon ferroalloys saturated with graphite, is a blend of at least three nonferrous metals and iron in carbide form, including a complex carbide of formula M.sub.7 C.sub.3 containing iron and manganese with the possible addition of chromium and another carbide of formula M'.sub.2 C/M'C containing molybdenum with the possible addition of vanadium and/or niobium. The carbidically bound carbon amounts to at least 4%, by weight, of the ferroalloy composition and may constitute between 10% and 60% of the carbon of the sinterable powder mixture to which elemental carbon may be added as graphite. As the mass of iron and ferroalloy particles compacted under high pressure is sintered at temperatures between about 1150.degree. and 1300.degree. C., the carbides lose their identity as their metals diffuse into the soft iron along with the carbon.