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:
Jan. 04, 1994
Filed:
Mar. 12, 1991
Wolfgang Althaus, Wuppertal, DE;
Atsushi Kumagai, Yonago, JP;
Wilkinson Sword Gesellschaft mit beschrankter Haftung, Solingen, DE;
Hitachi Metals Ltd., Tokyo, JP;
Abstract
Steel which is particularly useful for making a razor blade of high corrosion resistance contains more than 0.45%, but less than 0.55%, of carbon, 0.4 to 1.0% of silicon, 0.5 to 1.0% of manganese, 12 to 14% of chromium and 1.0 to 1.6% of molybdenum all by weight, in addition to iron and inevitable impurities, and has a carbide density of 100 to 150 particles per 100 square microns as annealed. The razor blade has a Vickers hardness of at least 620 and a carbide density of 10 to 45 particles per 100 square microns, and preferably has a specific distribution of residual austenite content. The improved properties of the razor blade are achieved by an improved process of heat treatment which includes austenitizing the steel at a temperature of 1075.degree. C. to 1120.degree. C., cooling it to a temperature between -60.degree. C. and -80.degree. C. for hardening it, and tempering it at a temperature of 250.degree. C. to 400.degree. C.