Usinor

Arcelor France

Arcelormittal

Nicolas Guelton

Michel Faral

Jean-Pierre Birat

Colin Scott

Philippe Cugy

Marie-Christine Theyssier

Catherine Juckum

François Stouvenot

Odile Faral

A hot-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 1200 MPa, the product P (strength (in MPa)&#xd7;elongation at break (in %)) of which is greater than 65 000 MPa % and the nominal chemical composition of which comprises, the contents being expressed by weight: 0.85%&#x2266;C&#x2266;1.05%; 16%&#x2266;Mn&#x2266;19%; Si&#x2266;2%; Al&#x2266;0.050%; S&#x2266;0.030%; P&#x2266;0.050%; N&#x2266;0.1%, and, optionally, one or more elements chosen from: Cr&#x2266;1%; Mo&#x2266;0.40%; Ni&#x2266;1%; Cu&#x2266;5%; Ti&#x2266;0.50%; Nb&#x2266;0.50%; V&#x2266;0.50%, the rest of the composition consisting of iron and inevitable impurities resulting from the smelting, the recrystallized surface fraction of said steel being equal to 100%, the surface fraction of precipitated carbides of said steel being equal to 0% and the mean grain size of said steel being less than or equal to 10 microns.

Method of producing austenitic iron/carbon/manganese steel sheets having very high strength and elongation characteristics and excellent homogeneity

The invention relates to a method for producing a siderurgical product made of carbon steel having a high copper content, according to which: &#x2014;a liquid steel having the composition: 0.0005%&#x2266;1%; 0.5&#x2266;Cu&#x2266;10%; 0&#x2266;Mn&#x2266;2%; 0&#x2266;Si&#x2266;5% 0&#x2266;Ti&#x2266;0.5%; 0&#x2266;Nb&#x2266;0.5%; 0&#x2266;Ni&#x2266;5%; 0&#x2266;Al&#x2266;2%, the remainder being iron and impurities, is produced;&#x2014;said liquid steel is poured directly in the form of a thin strip having a thickness of no more than 10 mm;&#x2014;the strip is subjected to forced cooling and/or is surrounded by a non-oxidizing atmosphere while having a temperature of more than 1000? C.; &#x2014;said thin strip is hot rolled at a reduction rate of at least 10%, the temperature at the end of the rolling process being such that all of the copper is still in a solid solution in the ferrite and/or austenite matrix;&#x2014;and the strip is coiled. The invention also relates to a siderurgical product obtained according to said method.

Method for the production of a siderurgical product made of carbon steel with a high copper content

Process for manufacturing strip made of an iron-carbon-manganese alloy, and strip thus produced

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Metz, France

Nicolas Guelton