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. 29, 2011
Filed:
Jul. 31, 2009
Yasuyoshi Hidaka, Osaka, JP;
Naoya Hirase, Osaka, JP;
Yasuhiro Kouchi, Osaka, JP;
Sumitomo Metal Industries, Ltd., Osaka-shi, JP;
Abstract
A plug material having a prescribed shape is prepared, the prepared plug material is thermally treated in a heat treatment atmosphere that contains at least 1.0 vol. % oxygen at a heat treatment temperature of at least 950° C. and less than 1050° C. and thus a plug having an oxide scale layeron the surface is manufactured. According to the manufacturing method, pores PO that extend along the surface SF of the plug material are formed under outer scale layerin the oxide scale layer, which allows cracks to be more easily propagated in the outer scale layer. Therefore, the outer scale layeris more easily peeled off than the conventional one.