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:
Oct. 08, 2019
Filed:
Apr. 14, 2015
Thyssenkrupp Steel Europe Ag, Duisburg, DE;
Jfe Steel Corporation, Tokyo, JP;
Brigitte Hammer, Voerde, DE;
Frank Hisker, Bottrop, DE;
Thomas Heller, Duisburg, DE;
Almir Dzafic, Dortmund, DE;
Richard G. Thiessen, Malden, NL;
Shinjiro Kaneko, Tokyo, JP;
Fusae Shiimori, Tokyo, JP;
THYSSENKRUPP STEEL EUROPE AG, Duisburg, DE;
JFE STEEL CORPORATION, Tokyo, JP;
Abstract
A method for producing a cold-rolled steel strip with a yield ratio Re/Rm of at least 0.7, the cold-rolled steel product including iron, unavoidable impurities and (in wt. %) C: 0.05-0.20%, Si: 0.25-1.00%, Mn: 1.0-3.0%, Al: 0.02-1.5%, Cr: 0.1-1.5%, N: <0.02%, P: <0.03%, S: <0.05% and optionally one or more of Ti, Mo, Nb, V, and B, Ti: up to 0.15%, Mo: <2%, Nb: <0.1%, V: <0.12%, and B: 0.0005-0.003%. The cold-rolled flat steel product undergoes heat treatment for 4.5-24 hours at a temperature of 150-400° C. Also, a cold rolled flat steel product discussed above having a structure including at least two phases, selected from (in vol. %) at least 10% tempered martensite, <10% bainite, <10% residual austenite and remainder ferrite, a yield ratio of at least 0.7, a tensile strength of ≥750 MPa and a hole expansion of at least 18%.