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:
Oct. 09, 2018
Filed:
Mar. 10, 2015
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Takahide Umehara, Futtsu, JP;
Yoshihiro Daito, Kisarazu, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A low alloy steel is heated to a temperature ranging from 550 to 620° C., and high Kand low Kvalue processes are performed for a total process time of A: 1.5 to 10 hours. In the high Kvalue process, a nitriding potential Kgiven by Formula (1): 0.15 to 1.50, the average Kvalue K: 0.30 to 0.80, and the process time is X in hours. In the low Kvalue process, which is performed after the high Kvalue process, a nitriding potential Kgiven by Formula (1): 0.02 to 0.25, the average Kvalue K: 0.03 to 0.20, and the process time is Y in hours. Average nitriding potential value Kdetermined by Formula (2) ranges from 0.07 to 0.30.=(NHpartial pressure)/(Hpartial pressure)]  (1)=()/  (2)