Arcelormittal

Arcelormittal Investigacion Y Desarrollo, S.l.

Véronique Hebert

Antoine Moulin

Pavan C Venkatasurya

Catherine Vinci

Mohamed Goune

Josée Drillet

Tom Waterschoot

Maya Gospodinova

Elena Uta

Gloria Restrepo Garces

Pavan Venkatasurya

A method for producing a steel sheet is provided. The method includes providing a cold-rolled steel sheet including in weight %: 0.15%≤C≤0.23%, 1.4%≤Mn≤2.6%, 0.6%≤Si≤1.5%, 0.02%≤Al≤1.0%, with 1.0%≤Si+Al≤2.0%, 0≤Nb≤0.035%, 0≤Mo≤0.3%, 0≤Cr≤0.3%, and a remainder of Fe and unavoidable impurities, annealing the steel sheet at an annealing temperature between Ac1 and Ac3 to obtaining at least 40% austenite and at least 40% intercritical ferrite, quenching the sheet from at least 600° C. at a cooling rate of at least 20° C./s to a quenching temperature between 180° C. and 260° C., heating the sheet to a partitioning temperature between 375° C. and 470° C. and maintaining the sheet at this partitioning temperature for a partitioning time Pt between 25 s and 440 s, then cooling the sheet to room temperature. A steel sheet is also provided.

Method for producing a high strength steel sheet having improved ductility and formability, and obtained steel sheet

A method for producing a coated steel sheet having a tensile strength TS of at least 1100 MPa, a total elongation TE according to ISO standard 6892-1 of at least 12%, the product TSxTE of the tensile strength by the total elongation being at least 14200 MPa %, and a hole expansion ratio HER according to ISO standard 16630:2009 of at least 25%, the method including the following successive steps:

Method for producing a high strength coated steel sheet having improved ductility and formability, and obtained coated steel sheet

A cold-rolled and annealed steel sheet is provided, the chemical composition of which comprises, the contents being expressed by weight percent:

High strength steel and manufacturing method

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Saint-Julien-les-Metz, France

Véronique Hebert