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:
Dec. 23, 2008
Filed:
May. 01, 2002
Jerry A. Tipps, Franklin, TN (US);
Larry E. Byrnes, Rochester Hills, MI (US);
Jerry A. Tipps, Franklin, TN (US);
Larry E. Byrnes, Rochester Hills, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
The present invention provides a carburizing method that involves heating a steel component quickly to a relatively high carburizing temperature (e.g. 1900 degrees F. and above), contacting the component at the relatively high carburizing temperature with a methane-containing carburization atmosphere for time to form a carbon-enriched surface case on the component, and cooling the component at a relatively slow rate effective to provide a relatively soft martensite-free surface case on the component. The component then is subjected to a hardening treatment wherein the carburized component is heated to a hardening temperature in the austenitic range followed by quenching and tempering to form a tempered martensitic surface case on an underlying non-martenistic core.