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:
Jul. 26, 1977
Filed:
May. 20, 1976
Applicant:
Inventors:
Bernard Pflieger, Chamalieres, FR;
Andre Reiniche, Ceyrat, FR;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ; C21D / ; C23C / ; C23C / ;
U.S. Cl.
CPC ...
148 / ; 148 165 ; 148 166 ; 148134 ;
Abstract
A medium-hard to hard thin steel sheet and a strip cut or stamped therefrom, both having an increased fatigue strength, are prepared by cold rolling a soft steel sheet, carburizing or carbo-nitriding the soft thinned sheet until a medium-hard to hard thin steel sheet is obtained and subjecting the resulting sheet or strip cut or stamped therefrom to a three-part heat treatment, which heat treatment involves first and second different austenizing operations, each followed by an identical two-step cooling operation, and a third lesser reheating and cooling operation.