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. 25, 1978
Filed:
Aug. 26, 1977
Tatsuro Kunitake, Toyonaka, JP;
Iwao Saito, Osaka, JP;
Kazuo Tsumura, Ibaraki, JP;
Masahiro Nishio, Amagasaki, JP;
Masaru Nishiguchi, Izumi, JP;
Yasutaka Okada, Nishinomiya, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A method of producing a tube with an ultra-high tensile strength over 255 kg/mm.sup.2 and remarkably improved ductility and toughness is provided, which comprises preparing a mother tube through hot extrusion of a steel consisting essentially of 15.0 - 18.5% by weight of Ni, 12.5 - 15.0% by weight of Co, 5.0 - 6.9% by weight of Mo, 1.00 - 1.28% by weight of Ti, 0.01 - 0.20% by weight of Al and the balance essentially iron, cold working the mother tube with a reduction in wall thickness of 5 - 25%, then raising the temperature of the resulting tube to a temperature of 800 - 950.degree. C in a period of from 20 minutes to 2 hours and maintaining the heated tube at this temperature for from 30 minutes to 3 hours, and, after cooling to or below room temperature, ageing the cooled tube at a temperature of 450.degree. - 550.degree. C for 1 - 10 hours.