Arcelormittal

Ian Alberto Zuazo Rodriguez

Patrick Barges

Irene De Diego Calderon

Astrid Perlade

Xavier Garat

Michel Soler

Irène De Diego Calderon

A cold rolled and heat treated steel sheet having a composition containing the following elements, expressed in percent by weight:

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

A method of production of a cold rolled and heat treated steel sheet has the following steps: providing a cold rolled steel sheet with a composition including the following elements, expressed in percent by weight: 0.15%≤carbon≤0.6%, 4%≤manganese≤20%, 5%≤aluminum≤15%, 0≤silicon≤2%, aluminum+ silicon≥6.5%, a remainder being composed of iron and unavoidable impurities caused by processing; heating said cold rolled steel sheet up to a soaking temperature between 80° and 950° C. during less than 600 seconds, then cooling the sheet down to a temperature in a range of 600° C. to room temperature, reheating the steel sheet to a soaking temperature of 150° C. to 600° C. during 10 s to 250 h, then cooling the sheet.

Method of production of a cold rolled and heat treated steel sheet to produce vehicle parts

A method of production of a cold rolled and heat treated steel sheet having the following steps: providing a cold rolled steel sheet with a composition with the following elements, expressed in percent by weight: 0.10%≤carbon≤0.6%; 4%≤manganese≤20%; 5%≤aluminum≤15%; 0≤silicon≤2% aluminium+silicon+nickel≥6.5%; and optionally at least one of certain optional elements; a remainder being composed of iron and unavoidable impurities caused by processing; heating the cold rolled steel sheet up to a soaking temperature between 750 and 950° C. during less than 600 seconds, then cooling the sheet down to room temperature; and reheating the steel sheet to a soaking temperature of 150° C. to 600° C. during 10 s to 1000 h, then further cooling the sheet.

Method of production of a cold rolled and heat treated steel sheet and use of such steel to produce vehicle parts

A cold rolled and heat treated steel sheet having a composition including the following elements, expressed in % by weight:

A cold rolled and annealed steel sheet includes by weight: 0.6&#x3c;C&#x3c;1.3%,15.0&#x3c;Mn&#x3c;35%, 6.0&#x3c;Al&#x3c;15%, Si&#x3c;2.40%, S&#x3c;0.015%, P&#x3c;0.1%, N&#x3c;0.1%, iron and inevitable impurities, optionally one or more of Ni, Cr and Cu in an individual amount of up to 3% and optionally one or more of B, Ta, Zr, Nb, V, Ti, Mo, and W in a cumulated amount of up to 2.0%, a microstructure of the sheet comprising at least 0.1% of intragranular kappa carbides, at least 80% of the kappa carbides have an average size below 30 nm, the remainder being made of austenite, an average grain size of the austenite being below 6 &#x3bc;m, an average aspect ratio of the austenite being between 1.5 and 6, an average grain size of the ferrite, when present being below 5 &#x3bc;m, and an average aspect ratio of the ferrite, when present, being 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.

Growing community of inventors

Metz, France

Ian Alberto Zuazo Rodriguez