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:
Aug. 13, 2019
Filed:
Jul. 22, 2013
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Kaori Kawano, Tokyo, JP;
Masahito Tasaka, Tokyo, JP;
Yoshiaki Nakazawa, Tokyo, JP;
Yasuaki Tanaka, Tokyo, JP;
Toshiro Tomida, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
A steel material comprising, by mass%, C: greater than 0.05% to 0.2%, Mn: 1% to 3%, Si: greater than 0.5% to 1.8%, Al: 0.01% to 0.5%, N: 0.001% to 0.015%, Ti or a sum of V and Ti: greater than 0.1% to 0.25%, Ti: 0.001% or more, Cr: 0% to 0.25%, Mo: 0% to 0.35%, the balance: Fe and impurities, comprising a multi-phase structure having a ferrite main phase and a second phase containing one or more of bainite, martensite and austenite, wherein an average nanohardness of the second phase is less than 6.0 GPa, an average grain diameter of all crystal grains in the main phase and the second phase is 3 μm or less, and a proportion of a length of small-angle grain boundaries where the misorientation is 2° to less than 15° in a length of all grain boundaries is 15% or more.