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:
Jun. 09, 2015
Filed:
Feb. 29, 2008
Hideki Hamatani, Tokyo, JP;
Shinji Kodama, Tokyo, JP;
Nobuo Mizuhashi, Futtsu, JP;
Sunao Takeuchi, Tokyo, JP;
Tomohiro Nakaji, Tokyo, JP;
Takashi Miyakawa, Tokyo, JP;
Hitoshi Asahi, Tokyo, JP;
Michitoshi Tanimoto, Tokyo, JP;
Michimasa Mukai, Tokyo, JP;
Hideki Hamatani, Tokyo, JP;
Shinji Kodama, Tokyo, JP;
Nobuo Mizuhashi, Futtsu, JP;
Sunao Takeuchi, Tokyo, JP;
Tomohiro Nakaji, Tokyo, JP;
Takashi Miyakawa, Tokyo, JP;
Hitoshi Asahi, Tokyo, JP;
Michitoshi Tanimoto, Tokyo, JP;
Michimasa Mukai, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
The present invention provides a method of production of electric resistance welded steel pipe able to stably reduce weld defects due to oxides by firing plasma and furthermore able to reduce plasma jet noise and comprises shaping steel plateinto a tube and electric resistance welding the abutting end facesduring which blowing on at least the abutting end facesin the regionat the welding upstream side from the weld pointwhere the temperature becomes 650° C. or more a reducing high temperature (pseudo) laminar plasma obtained by applying voltage to a reducing gas containing Hgas: 2 to 50 vol % to which is added a balance of Ar gas alone or a mixed gas of Ar gas to which Ngas, He gas, or both are added. At that time, it is preferable to make the applied voltage over 120V and the make the plasma blowing conditions satisfy the following formula (1).