Arcelormittal

Arcelormittal France

Xavier Garat

Astrid Perlade

Olivier Bouaziz

Jean-Louis Uriarte

Ian Alberto Zuazo Rodriguez

Michel Soler

Irène De Diego Calderon

Josee Drillet

Josée Drillet

Irene De Diego Calderon

A cold rolled and annealed steel sheet includes by weight: 0.6≤C≤1.3%, 15.0≤Mn≤35%, 5≤Al≤15%, Si≤2.40%, S≤0.03%, P≤0.1%, N≤0.1%, possibly one or more optional elements chosen among Ni, Cr and Cu in an respective amount of up to 4.0%, up to 3.0% and up to 3.0% and possibly one or more elements chosen among B, Ta, Zr, Nb, V, Ti, Mo, and W in a cumulated amount of up to 2.0%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, the microstructure of the sheet including optionally up to 3% of kappa carbides, optionally up to 10.0% of granular ferrite, the remainder being made of austenite, the average grain size and average aspect ratio of the austenite being respectively below 6 μm and comprised between 1.5 and 6 and the average grain size and average aspect ratio of the ferrite, when present, being respectively below 5 μm and below 3.0.

Cold rolled and annealed steel sheet, method of production thereof and use of such steel to produce vehicle parts

A rolled steel sheet is provided. The rolled steel sheet has a mechanical strength greater than or equal to 600 MPa and an elongation at fracture that is greater than or equal to 20%. A a method for its fabrication is also provided. The chemical composition of the steel sheet includes 0.10&#x2264;C&#x2264;0.30%, 6.0&#x2264;Mn&#x2264;15.0%, 6.0&#x2264;Al&#x2264;15.0%, and optionally one or more elements selected from among: Si&#x2264;2.0%, Ti&#x2264;0.2%, V&#x2264;0.6% and Nb&#x2264;0.3%. The remainder of the composition includes iron and the unavoidable impurities resulting from processing. The ratio of the weight of manganese to the weight of aluminum is such that The microstructure of the sheet includes ferrite, austenite and up to 5% Kappa precipitates in area fraction.

Low-density hot-or cold-rolled steel, method for implementing same and use thereof

A cold-rolled and annealed ferritic steel sheet is provided. The steel has a composition comprising, expressed by weight: &#x3a3;di denotes the total length of grain boundaries containing &#x3ba; precipitates relative to an area (A) and &#x3a3;Li denotes the total length of the grain boundaries relative to the area (A). A content of carbon in solid solution is less than 0.005% by weight, and the cold-rolled and annealed ferritic steel sheet has a thickness between 0.6 mm and 1.5 mm. A skin part or structural part for the automotive field is also provided.

Low density steel having good drawability

The invention relates to a hot-rolled ferritic steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.001&#x2266;C&#x2266;0.15%, Mn&#x2266;1%, Si&#x2266;1.5%, 6%&#x2266;Al&#x2266;10%, 0.020%&#x2266;Ti&#x2266;0.5%, S&#x2266;0.050%, P&#x2266;0.1%, and, optionally, one or more elements chosen from: Cr&#x2266;1%, Mo&#x2266;1%, Ni&#x2266;1%, Nb&#x2266;0.1%, V&#x2266;0.2%, B&#x2266;0.010%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the average ferrite grain size dmeasured on a surface perpendicular to the transverse direction with respect to the rolling being less than 100 microns.

Low-density steel having good drawability

Growing community of inventors

Homecourt, France

Xavier Garat