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. 03, 2007
Filed:
Mar. 03, 2006
Hisashi Amaya, Kyoto, JP;
Kazuhiro Ogawa, Nishinomiya, JP;
Kunio Kondo, Sanda, JP;
Masayuki Sagara, Nishinomiya, JP;
Hiroyuki Hirata, Neyagawa, JP;
Hisashi Amaya, Kyoto, JP;
Kazuhiro Ogawa, Nishinomiya, JP;
Kunio Kondo, Sanda, JP;
Masayuki Sagara, Nishinomiya, JP;
Hiroyuki Hirata, Neyagawa, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
This invention relates to a welded line pipe structure for transporting corrosive petroleum or natural gas. It is constituted by martensitic stainless steel pipes containing 8–16% Cr and at most 0.05% C. By suitably controlling the welding conditions at the time of girth welding of the steel pipes so as to ensure that the Cr concentration in grain boundary Cr-depleted portions existing immediately beneath a weld oxide scale is at least 5%, the occurrence of SCC in a high temperature COenvironment can be prevented.