Usinor

Sollac

Arcelormittal

Arcelor France

Michel Faral

Christian Marchionni

Catherine Juckum

Mohamed Bouzekri

Colin Scott

Nicolas Guelton

Patrice Vicente

Fran&ccedil;oise Commarieu

Fran&ccedil;ois Poirier

Jacques Selaries

Odile Faral

Michel Babbit

Jean-Pierre Birat

Jean-Michel Damasse

Christophe Issartel

Yann Le Papillon

Alain Leclercq

Philippe Rocabois

Michel Guttmann

Jean-Hubert Schmitt

Helene Regle

Thierry Iung

H&eacute;l&egrave;ne Regle

A hot-rolled austenitic iron/carbon/manganese steel sheet is provided. The strength of which is greater than 900 MPa, the product (strength (in MPa)&#xd7;elongation at fracture (in %)) of which is greater than 45000 and the chemical composition of which includes, the contents being expressed by weight 0.5%&#x2266;C&#x2266;0.7%, 17%&#x2266;Mn&#x2266;24%, Si&#x2266;3%, Al&#x2266;0.050%, S&#x2266;0.030%, P&#x2266;0.080% and N&#x2266;0.1%. A remainder of the composition includes iron and inevitable impurities resulting from the smelting. A recrystallized fraction of the structure of the steel is greater than 75%, a surface fraction of precipitated carbides of the steel is less than 1.5% and a mean grain size of the steel is less than 18 microns. A reinforcing element is also provided.

Method of producing austenitic iron/carbon/manganese steel sheets having a high strength and excellent toughness and being suitable for cold forming, and sheets thus produced

The invention relates to a hot rolled sheet which is made from austenitic iron/carbon/manganese steel and which has a resistance of greater than 900 MPa, whereby: resistance (MPa) x elongation at rupture (%) is greater than 45000. The chemical composition of the inventive sheet comprises the following concentrations expressed as weight: 0.5%=C=0.7%, 17%=Mn=24%, Si=3%, Al=0.05%, S=0.03%, P=0.08%, N=0.1% and, optionally, one or more elements such as Cr=1%, Mo=0.4%, Ni=1%, Ti=0.5%, Nb=0.5%, V=0.5%, Cu=5%, Cu=5%, the rest of the composition comprising iron and impurities resulting from production. According to the invention, the recrystallised fraction of the steel is greater than 75% and the surface fraction of precipitated carbides of the steel is less than 1.5%, the average grain size of the steel being less than 18 micrometers.

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

A metallurgical product, made of carbon steel and to be galvanized, which is in the form of a strip or of a sheet obtained from a continuously cast intermediate product having the following composition by weight: 0.0005%&#x2266;C&#x2266;0.15%; 0.08%&#x2266;Mn&#x2266;2%; Si&#x2266;0.040%; Al&#x2266;0.010%; Al&#x2266;0.004%; 0.0050%&#x2266;O&#x2266;0.0500%; P&#x2266;0.20%; S&#x2266;0.10%; each of Cu, Cr, Ni, Mo, W, Co&#x2266;1%; each of Ti, Nb, V, Zr&#x2266;0.5%; each of Sn, Sb, As&#x2266;0.1%; B&#x2266;0.1%; N&#x2266;0.0400%; and the remainder being iron and impurities. Also, a process for obtaining a metallurgical intermediate product, which includes: producing in a ladle a liquid steel the composition of which is as above, and in which the dissolved oxygen content is maintained between 0.0050 and 0.0500% by the establishment of a chemical equilibrium between the metal and the ladle slag; and casting the steel on a continuous casting machine.

Metallurgical product of carbon steel, intended especially for galvanization, and processes for its production

The invention relates to the iron and steel industry. More specifically, the invention describes the manufacture of steel strip intended to be converted into thin packaging, such as for drinks and preserved food.

Method for making carbon steel bands, in particular packaging steel bands, and resulting bands

A process for manufacturing carbon-steel strip having a thickness of less than or equal to 10 mm directly from liquid steel, by casting said liquid steel between the lateral surfaces, made of copper or copper alloy, of two internally cooled rotating horizontal rolls.

Process for manufacturing carbon-steel strip by twin-roll continuous casting, product produced and apparatus

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

Method of fabricating &ldquo;TRIP&rdquo; steel in the form of thin strip, and thin strip obtained in this way

The subject for the invention is a process for manufacturing strip. The process includes casting directly from liquid metal a steel strip 1.5 to 10 mm in thickness, subjecting the cast steel strip, in the austenitic phase, to a first hot rolling operation in one or more steps at a temperature of between 950&deg; C. and the Ar,temperature of said strip with an overall reduction ratio of at least 10%, then subjecting the hot rolled strip, in the ferritic phase, to a second hot rolling operation in one or more steps at a temperature below 850&deg; C., with an overall reduction ratio of at least 50% in the presence of a lubricant, so as to obtain a hot-rolled sheet with a thickness of less than or equal to 2 mm, and recrystallizing the hot rolled sheet at a temperature between 700 and 800&deg; C. The composition of the steel strip comprises (in weight %): carbon less than 0.1%, manganese from 0.03 to 2%, silicon from 0 to 0.5%, phosphorus from 0 to 0.1%, boron from 0 to 0.002%, titanium from 0 to 0.15%, balance iron and impurities.

Process for manufacturing drawable sheet by direct casting of thin strip, and sheet thus obtained

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Metz, France

Michel Faral