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:
Mar. 17, 2009
Filed:
Oct. 04, 2002
Tatsuo Yokoi, Oita, JP;
Teruki Hayashida, Oita, JP;
Natsuko Sugiura, Futtsu, JP;
Takaaki Nakamura, Oita, JP;
Takehiro Nakamoto, Oita, JP;
Tatsuo Yokoi, Oita, JP;
Teruki Hayashida, Oita, JP;
Natsuko Sugiura, Futtsu, JP;
Takaaki Nakamura, Oita, JP;
Takehiro Nakamoto, Oita, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The present invention provides a high-strength thin steel sheet drawable and excellent in a shape fixation property and a method of producing the same. For the steel sheet, on a plane at the center of the thickness of a steel sheet, the average ratio of the X-ray strength in the orientation component group of {100}<011> to {223}<110> to random X-ray diffraction strength is 2 or more and the average ratio of the X-ray strength in three orientation components of {554}<225>, {111}<112> and {111}<110> to random X-ray diffraction strength is 4 or less. The arithmetic average of the roughness Ra of at least one of the surfaces is 1 to 3.5 μm; the surfaces of the steel sheet are covered with a composition having a lubricating effect; and the friction coefficient of the steel sheet surfaces at 0 to 200° C. is 0.05 to 0.2. Further, the present invention also relates to a method of producing said steel sheet, characterized by: rolling a steel sheet having the chemical components specified in the present invention at a total reduction ratio of 25% or more in the temperature range of the Artransformation temperature +100° C. or lower.