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. 03, 2008
Filed:
Sep. 22, 2004
Tatsuo Yokoi, Oita, JP;
Tetsuya Yamada, Oita, JP;
Osamu Kawano, Oita, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
An exemplary hot rolled steel sheet for processing can include, in terms of percent by mass, C of 0.01 to 0.2%; Si of 0.01 to 0.3%; Mn of 0.1 to 1.5%; P of ≦0.1%; S of ≦0.03%; Al of 0.001 to 0.1%; N of ≦0.006%; and as a remainder, Fe and unavoidable impurities. The microstructure may include a main phase in the form of polygonal ferrite and a hard second phase, a volume fraction of the hard second phase is 3 to 20%, a hardness ratio (hardness of the hard second phase/hardness of the polygonal ferrite) is 1.5 to 6, and a grain size ratio (e.g., grain size of the polygonal ferrite/grain size of the hard second phase) is 1.5 or more.