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. 03, 1990
Filed:
Jan. 13, 1989
Frank Hengerer, Schwebheim, DE;
Gerhard Mend, Schweinfurt, DE;
Ulf Sjoblom, Goteborg, SE;
Roger Bjorn, .ANG.ngered, SE;
SKF GmbH, Schweinfurt, DE;
Abstract
In a process for case-hardening rolling bearing elements of low-alloy nickeliferous steel, the rolling bearing elements are carburized in a dissociating carburizing gas, cooled down, heated to hardening temperature, austenitized in the carburized layer and, lastly, quenched. So that no brittleness of the rolling bearing elements takes place upon carburization due to dissociated hydrogen, the bearing elements are cooled from carburizing heat down to about 300.degree. C. in agitated inert gas and then held at this temperature, so that sufficient dissociated hydrogen escapes from the carburized layer of the rolling bearing elements. Subsequent heating of the said elements to hardening temperature or to intermediate annealing temperature is advantageously effected after holding at 300.degree. C.