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:
Nov. 20, 1990
Filed:
Jul. 25, 1989
Shinya Shibata, Hiroshima, JP;
Yoshihisa Miwa, Hiroshima, JP;
Yoshihiko Kojima, Higashi-Hiroshima, JP;
Yukio Arimi, Hiroshima, JP;
Mazda Motor Corporation, Hiroshima, JP;
Abstract
A method of carburizing and quenching involves the following three steps of: pre-carburizing a steel member containing Cr with precipitating carbide by heating to achieve a surface carbon concentration of not less than 1%; spheroidizing the carbide obtained by alternately holding the steel member at a temperature slightly above and slightly below the A.sub.1 transformation temperature under a carbon potential of from 0.5 to 1.0%; and carburizing and quenching or carbo-nitriding and quenching the steel member followed by reheating at not more than the heating temperature of pre-carburizing.