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:
May. 19, 2020
Filed:
Mar. 18, 2016
Jfe Steel Corporation, Tokyo, JP;
JFE STEEL CORPORATION, Tokyo, JP;
Abstract
A high-strength steel sheet having a high yield ratio and excellent stretch flangeability, and a method for producing the high-strength steel sheet. The high-strength steel sheet has a composition containing, by mass: C: 0.02% or more and less than 0.10%, Si: less than 0.10%, Mn: less than 1.0%, P: 0.10% or less, S: 0.020% or less, Al: 0.01% or more and 0.10% or less, N: 0.010% or less, Nb: 0.005% or more and less than 0.070%, and the balance being Fe and inevitable impurities; and a microstructure including, by area: ferrite: 85% or more, pearlite: 0% to 15%, and a total of martensite, retained austenite and cementite: 0% to 3%. The average crystal grain diameter of the ferrite is 15.0 μm or less. The grain diameter of a Nb carbide is 5 to 50 nm. The amount of Nb carbide precipitate is 0.005% to 0.050% in terms of volume fraction.