Arcelormittal

Arcelormittal France

Gerard Petitgand

Colin Scott

Patrick Barges

Sebastien Allain

Marie-Christine Theyssier

Thierry Iung

Nicolas Charbonnier

Fabien Perrard

A method for the manufacture of a TWIP steel is provided including: (A) feeding of a slab comprising by weight: 0.5&#x3c;C&#x3c;1.2%, 13.0&#x2264;Mn&#x3c;25.0%, S&#x2264;0.030%, P&#x2264;0.080%, N&#x2264;0.1%, Si&#x2264;3.0%, 0.051%&#x2264;Al&#x2264;4.0%, 0.1&#x2264;V&#x2264;2.5%, and on a purely optional basis, one or more of Nb&#x2264;0.5%, B&#x2264;0.005%, Cr&#x2264;1.0%, Mo&#x2264;0.40%, Ni&#x2264;1.0%, Cu&#x2264;5.0%, Ti&#x2264;0.5%, 0.06&#x2264;Sn&#x2264;0.2%, the remainder of the composition being made of iron and inevitable impurities resulting from the elaboration, (B) reheating the slab and hot rolling the slab to provide a hot rolled slab, (C) coiling the hot rolled slab to provide a coiled slab, (D) first cold-rolling the coiled slab to provide a first cold rolled slab, (E) recrystallization annealing the first cold rolled slab such that an annealed steel sheet having an UTSis obtained and (F) second cold-rolling the annealed steel sheet with a reduction rate CR % that satisfies the following equation A: 1216.472&#x2212;0.98795*UTS&#x2264;(&#x2212;0.0008*UTS+1.0124)*CR %+(0.0371*UTS&#x2212;29.583)*CR %.

Method for the manufacture of TWIP steel sheet having an austenitic matrix

A method for the manufacture of a cold rolled, recovered TWIP steel sheet coated with a metallic coating is provided including the following steps: (A) the feeding of a slab having the following composition: 0.1&#x3c;C&#x3c;1.2%, 13.0&#x2264;Mn&#x3c;25.0%, S&#x2264;0.030%, P&#x2264;0.080%, N&#x2264;0.1%, Si&#x2264;3.0%, and on a purely optional basis, one or more elements such as Nb&#x2264;0.5%, B&#x2264;0.005%, Cr&#x2264;1.0%, Mo&#x2264;0.40%, Ni&#x2264;1.0%, Cu&#x2264;5.0%, Ti&#x2264;0.5%, V&#x2264;2.5%, Al&#x2264;4.0%, 0.06&#x2264;Sn&#x2264;0.2%, the remainder of the composition making up of iron and inevitable impurities resulting from elaboration; (B) Reheating such slab and hot rolling it; (C) A coiling step; (D) A first cold-rolling; (E) A recrystallization annealing; (F) A second cold-rolling; and (G) A recovery heat treatment performed by hot-dip coating.

Method for producing a TWIP steel sheet having an austenitic microstructure

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

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Plesnois, France

Gerard Petitgand