Abstract: A steel sheet that is welded and then cold rolled to a thickness between 0.5 mm and 3 mm, the deformation ratio created by cold rolling in the base metal is equal to ?MB, for which the deformation ratio created by the cold rolling in the welded joint is equal to ?S, where: 0.4 ? ?S ? ? M ? B < 0.7 .

Abstract: A pickling process of a metallic strip is provided including the steps of: passing said metallic strip through at least a pickling bath being at a temperature between 1 and 100° C., applying an alternating current, having a current density of 1x102 to 1x105 A.m?2 of unit surface of said metallic strip to said metallic strip passing through said at least one pickling bath.

Abstract: A method for the manufacture of a TWIP steel is provided including: (A) feeding of a slab comprising by weight: 0.5<C<1.2%, 13.0?Mn<25.0%, S?0.030%, P?0.080%, N?0.1%, Si?3.0%, 0.051%?Al?4.0%, 0.1?V?2.5%, and on a purely optional basis, one or more of Nb?0.5%, B?0.005%, Cr?1.0%, Mo?0.40%, Ni?1.0%, Cu?5.0%, Ti?0.5%, 0.06?Sn?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 UTSannealed is obtained and (F) second cold-rolling the annealed steel sheet with a reduction rate CR % that satisfies the following equation A: 1216.472?0.98795*UTSannealed?(?0.0008*UTSannealed+1.0124)*CR %2+(0.0371*UTSannealed?29.583)*CR %.

Abstract: A method for the manufacture of a cold-rolled steel sheet of thickness ef between 0.5 mm and 3 mm is provided. At least two hot-rolled sheets of thickness ei are supplied and butt welded, so as to create a welded joint (S1) with a direction perpendicular to the direction of hot rolling. The at least two hot-rolled sheets are pickled by continuous passage through a bath, then the assembly is cold rolled, in a step (L1), to an intermediate thickness eint, the direction of cold rolling (DL1) coinciding with the direction of hot rolling. The cold rolling is carried out with a reduction ratio ? 1 = Ln ? ( e i e int ) such that: 0 . 3 ? 5 ? Ln ? ? ( ei e ? ? int ) Ln ? ? ( e ? i e ? f ) ? 0 . 6 ? 5 , then the welded joint (S1) is removed so as to obtain at least two intermediate cold-rolled sheets.

Abstract: A steel sheet that is welded and then cold rolled to a thickness between 0.5 mm and 3 mm, the deformation ratio created by cold rolling in the base metal is equal to ?MB, for which the deformation ratio created by the cold rolling in the welded joint is equal to ?S, where: 0.4 ? ?S ? ? M ? B < 0.7 .

Abstract: A method for the manufacture of a cold-rolled steel sheet of thickness ef between 0.5 mm and 3 mm is provided. At least two hot-rolled sheets of thickness ei are supplied and butt welded, so as to create a welded joint (S1) with a direction perpendicular to the direction of hot rolling. The at least two hot-rolled sheets are pickled by continuous passage through a bath, then the assembly is cold rolled, in a step (L1), to an intermediate thickness eint, the direction of cold rolling (DL1) coinciding with the direction of hot rolling. The cold rolling is carried out with a reduction ratio ? 1 = Ln ? ( e i e int ) such that: 0 . 3 ? 5 ? Ln ? ? ( ei e ? ? int ) Ln ? ? ( e ? i e ? f ) ? 0 . 6 ? 5 , then the welded joint (S1) is removed so as to obtain at least two intermediate cold-rolled sheets.

Abstract: A method for the manufacture of a TWIP steel is provided including: (A) feeding of a slab comprising by weight: 0.5<C<1.2%, 13.0?Mn<25.0%, S?0.030%, P?0.080%, N?0.1%, Si?3.0%, 0.051%?Al?4.0%, 0.1?V?2.5%, and on a purely optional basis, one or more of Nb?0.5%, ?B?0.005%, Cr?1.0%, Mo?0.40%, Ni?1.0%, Cu?5.0%, Ti?0.5%, 0.06?Sn?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 UTSannealed is obtained and (F) second cold-rolling the annealed steel sheet with a reduction rate CR % that satisfies the following equation A: 1216.472?0.98795*UTSannealed?(?0.0008*UTSannealed+1.0124)*CR %2+(0.0371*UTSannealed?29.583)*CR %.

Abstract: A cold rolled and recovered TWIP steel sheet is provided having an austenitic matrix including by weight: 0.71<C<1.2%, 13.0?Mn<25.0%, S?0.030%, P?0.080%, N?0.1%, 0.1?Si?3.0%, 0.1?V?2.50%, and on a purely optional basis, one or more elements such as Cu?5.0%, Al?4.0%, Nb?0.5%, B?0.005%, Cr?1.0%, Mo?0.40%, Ni?1.0%, Ti?0.5%, 0.06?Sn?0.2%, the remainder of the composition being made of iron and inevitable impurities resulting from elaboration.

Abstract: A hot-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 1200 MPa, the product P (strength (in MPa)×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%?C?1.05%; 16%?Mn?19%; Si?2%; Al?0.050%; S?0.030%; P?0.050%; N?0.1%, and, optionally, one or more elements chosen from: Cr?1%; Mo?0.40%; Ni?1%; Cu?5%; Ti?0.50%; Nb?0.50%; V?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.

Abstract: A hot-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 1200 MPa, the product P (strength (in MPa)×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%?C?1.05%; 16%?Mn?19%; Si?2%; Al?0.050%; S?0.030%; P?0.050%; N?0.1%, and, optionally, one or more elements chosen from: Cr?1%; Mo?0.40%; Ni?1%; Cu?5%; Ti?0.50%; Nb?0.50%; V?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.