Arcelormittal

Usinor

Arcelormittal France

Thyssenkrupp Steel Europe Ag

Arcelor France

Thyssenkrupp Steel Ag

Arcelormittal Investigacion Y Desarrollo, S.l.

Colin Scott

Philippe Cugy

Christian Allely

Daniel Chaleix

Mohamed Bouzekri

Patrick Choquet

Michel Faral

Alain Lamande

Christophe Olier

Patrick Barges

Marie-Christine Theyssier

Gerard Petitgand

Nicolas Guelton

François Stouvenot

Anne Dez

Fabien Perrard

Maurita Roscini

Dominique Cornette

Gérard Petitgand

A hot-rolled or cold-rolled steel plate having a composition including, in weight percent: 0.6%&#x2264;C&#x2264;0.9%; 17%&#x2264;Mn&#x2264;22%; 0.2%&#x2264;Al&#x2264;0.9%; 0.2%&#x2264;Si&#x2264;1.1%; with 0.85%&#x2264;Al+Si&#x2264;1.6%; 1.2%&#x2264;Cu&#x2264;1.7%; S&#x2264;0.030%; P&#x2264;0.080%; N&#x2264;0.1%; 0&#x3c;Nb&#x2264;0.25%; 0&#x3c;V&#x2264;0.5%; 0&#x3c;Ti&#x2264;0.5%; 0&#x3c;Ni&#x2264;2%; trace amounts &#x2264;Cr&#x2264;2% and B&#x2264;0.010% is provided. A remainder of the composition includes iron and impurities resulting from production of the steel plate. A method for manufacturing a steel plate and use of the steel plate in the automotive industry is also provided.

Hot-rolled or cold-rolled steel plate

An austenitic steel sheet excellent in resistance to delayed cracking is provided. The composition of said steel comprises in weight: The composition may optionally include B, Ni and/or Cu. The remainder of the composition includes iron and unavoidable impurities inherent to fabrication, including hydrogen. The quantity Xp of the at least one metallic element under the form of carbides, nitrides or carbonitrides is, in weight: The hydrogen content Hmax designating the maximal hydrogen content that can be measured from a series of at least five specimens, and the quantity Xp, in weight, is such that: 

Iron-carbon-manganese austenitic steel sheet

A process for fabricating a steel sheet is provided. The process includes soaking a steel sheet. The steel has a composition including iron, carbon, manganese, silicon, aluminum, sulfur, phosphorus and nitrogen and at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, and chromium. A quantity Xof metallic element under the form of carbides, nitrides or carbonitrides is, by weight:0.030%&#x2264;V&#x2264;0.40%;0.030%&#x2264;Ti&#x2264;0.50%;0.040%&#x2264;Nb&#x2264;0.40%;0.14%&#x2264;Mo&#x2264;0.44%; or0.070%&#x2264;Cr&#x2264;0.6%.The soaking step occurs under a pure nitrogen or argon atmosphere with a dew point lower than &#x2212;30&#xb0; C. at a soaking temperature &#x3b8; between 250 and 900&#xb0; C. and with a dynamic circulation of a regenerated atmosphere.

Process for manufacturing iron-carbon-maganese austenitic steel sheet with excellent resistance to delayed cracking

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

Steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.08%&#x2266;C&#x2266;0.23%, 1%&#x2266;Mn&#x2266;2%, 1&#x2266;Si&#x2266;2%, Al&#x2266;0.030%, 0.1%&#x2266;V&#x2266;0.25%, Ti&#x2266;0.010%, S&#x2266;0.015%, P&#x2266;0.1%, 0.004%&#x2266;N&#x2266;0.012%, and, optionally, one or more elements chosen from: Nb&#x2266;0.1%, Mo&#x2266;0.5%, Cr&#x2266;0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Method of producing high-strength steel plates with excellent ductility and plates thus produced

An austenitic steel sheet excellent in resistance to delayed cracking, the composition of said steel comprising, in weight: 0,35%&#x3c;C&#x3c;1,05%, 15%&#x3c;Mn&#x3c;26%, Si&#x3c;3%, Al&#x3c;0,050%, S&#x3c;0,030%, P&#x3c;0,080%, N&#x3c;0,1%, at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, chromium: 0,050%&#x3c;V&#x3c;0,50%, 0,040%&#x2266;Ti&#x3c;0,50%, 0,070%&#x3c;Nb&#x3c;0,50%, 0,14%&#x3c;Mo&#x3c;2%, 0,070%&#x3c;Cr&#x3c;2% and optionally, one or several elements chosen among 0,0005%&#x3c;B&#x3c;0,010%, Ni&#x3c;2%, Cu&#x3c;5%, the remainder being iron and unavoidable impurities inherent to fabrication, including hydrogen, the quantity Xp of said at least one metallic element under the form of carbides, nitrides or carbonitrides being, in weight: 0,030%&#x3c;VP&#x3c;0,40%, 0,030%&#x3c;Tip&#x3c;0,50%, 0,040%&#x3c;Nbp&#x3c;0,40%, 0,14%&#x3c;Mop&#x3c;0,44%, 0,070%&#x3c;Crp&#x3c;0,6%, the hydrogen content Hmax designating the maximal hydrogen content that can be measured from a series of at least five specimens, and the quantity Xp, in weight, being such that (I) &#x3c;3,3. 

Process for manufacturing iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking, and sheet 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.

Iron-carbon-manganese austenitic steel sheet, the chemical composition of which comprises, the contents being expressed by weight: 0.45%&#x2266;C&#x2266;0.75%; 15%&#x2266;Mn&#x2266;26%; Si&#x2266;3%; Al&#x2266;0.050%; S&#x2266;0.030%; P&#x2266;0.080%; N&#x2266;0.1%; at least one metal element chosen from vanadium, titanium, niobium, chromium and molybdenum, where 0.050%&#x2266;V&#x2266;0.50%; 0.040%&#x2266;Ti&#x2266;0.50; 0.070%&#x2266;Nb&#x2266;0.50%; 0.070%&#x2266;Cr&#x2266;2%; 0.14%&#x2266;Mo&#x2266;2%; and, optionally, one or more elements chosen from 0.0005%&#x2266;B&#x2266;0.003%; Ni&#x2266;1%; Cu&#x2266;5%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the amounts of said at least one metal element in the form of precipitated carbides, nitrides or carbonitrides being: 0.030%&#x2266;V&#x2266;0.150%; 0.030%&#x2266;Ti&#x2266;0.130%; 0.040%&#x2266;Nb&#x2266;0.220%; 0.070%&#x2266;Cr&#x2266;0.6%; 0.14%&#x2266;Mo&#x2266;0.44%.

Method for producing austenitic iron-carbon-manganese metal sheets, and sheets produced thereby

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 coating plant includes a device for running a sheet to be coated along a traveling path past a window for the evaporation or sublimation of elements A an B, sources for the evaporation or sublimation of elements A and element B placed successively in a direction parallel to the traveling path so as to emit elements A and B through the window and a screen for reducing the angle of emission from the source of element B below the limit represented by an exit edge of the window, the screen being mounted so as to move translationally perpendicular to the traveling path and to move along the traveling path between the source of element A and the source of element B so as to obtain either a &mdash;A&mdash;AB&mdash;A&mdash; or a &mdash;B&mdash;AB&mdash;B&mdash;coating.

Steel sheet provided with a coating comprising a main layer of zinc-chromium alloy the predominant phase of which has a delta and/or zeta structure

The coating plant includes a device for running a sheet to be coated along a traveling path past a window for the evaporation or sublimation of elements A an B, sources for the evaporation or sublimation of elements A and element B placed successively in a direction parallel to the traveling path so as to emit elements A and B through the window and a screen for reducing the angle of emission from the source of element B below the limit represented by an entry edge of the window, the screen being mounted so as to move translationally perpendicular to the traveling path and to move along the traveling path between the source of element A and the source of element B so as to obtain either a -A-AB-A- or a -B-AB-B- coating.

Growing community of inventors

Montigny les Metz, France

Colin Scott