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:
Sep. 20, 1988
Filed:
May. 21, 1986
Nippon Steel Corporation, Tokyo, JP;
Abstract
A method for the production of an electric seam welded steel pipe for oil-well use which has good resistance to collapse pressure and souring, by providing a steel containing 0.08-0.26% C by weight, 0.8-1.9% Mn by weight, 0.5% or less Si by weight, the remainder being Fe and unavoidable impurities, subjecting the steel to hot rolling, and hardening, and coiling the treated steel at a temperature not exceeding 250.degree. C., after which the steel is then formed into tubular form and welded by electric resistance welding to produce an electric seam welded pipe, and the weld heat affected zones of the pipe are subjected to heating to a temperature of 900.degree. C. or more to effect hardening, and then the whole pipe is tempered.