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:
Nov. 12, 2019
Filed:
Jul. 03, 2015
Arcelormittal, Luxembourg, LU;
Gunhild Föjer, Destelbergen, BE;
Michel Soler, Maizieres-les-Metz, FR;
Jean-Christophe Hell, Maizieres-les-Metz, FR;
ArcelorMittal, Luxembourg, LU;
Abstract
A method for manufacturing a high-strength sheet having improved formability and ductility accord which the chemical composition of the steel contains, in percent by weight: 0.25%<C≤0.4% 2.3%≤Mn≤3.5% 2.3%≤Si≤3% Al≤0.040% the remainder being Fe and unavoidable impurities, the method comprising the steps of annealing a rolled sheet made of said steel by soaking it at an annealing temperature AT higher than the Actransformation point of the steel, quenching the sheet by cooling it down to a quenching temperature QT between Ms−65° C. and Ms−115° C., being in order to obtain a final structure containing at least 65% of martensite and at least 5% of residual austenite, the sum of the ferrite and bainite contents being less than 10%, Ms being the Ms transformation point of the steel according to the Andrews formula, heating the sheet up to an overaging temperature PT between 360° C. and 500° C. and maintaining it at said temperature for a time Pt between 10 s and 600 s, and cooling the sheet down to the ambient temperature.