United States Steel Corporation

Matthew Michael McCosby

David Paul Hoydick

Eduardo Augusto Silva

The present invention provides steel sheet products having controlled compositions that are subjected to two-step annealing processes to produce sheet products having desirable microstructures and favorable mechanical properties such as high strength and ultra-high formability. Steels processed in accordance with the present invention exhibit combined ultimate tensile strength and total elongation (UTS·TE) properties of greater than 25,000 MPa %. Steels with these properties fall into the category of Generation 3 advanced high strength steels, and are highly desired by various industries including automobile manufacturers.

Annealing processes for making high strength steel products

The present invention provides steel sheet products having controlled compositions that are subjected to two-step annealing processes to produce sheet products having desirable microstructures and favorable mechanical properties such as high strength and ultra-high formability. The steel sheet products may be cold rolled or hot rolled. Steels processed in accordance with the present invention exhibit favorable combined ultimate tensile strength and total elongation (UTS•TE) properties, and may fall into the category of Generation 3 advanced high strength steels, desirable in various industries including automobile manufacturers.

High strength annealed steel products and annealing processes for making the same

Methods of producing high strength continuously cast hot rolled steel sheet products are disclosed. The methods include continuously casting a steel slab and then hot rolling with finish rolling on a hot strip mill, quenching on the hot strip mill to form a predominantly matrensitic microstructure, and performing a thermal cycling step including soaking at an intercritical temperature followed by holding at a lower temperature. The resultant hot rolled steel sheet products have a microstructure comprising ferrite and retained austenite. Steels processed in accordance with the present invention exhibit favorable combined ultimate tensile strength and total elongation (UTS&#xb7;TE) properties, and may fall into the category of Generation 3 advanced high strength steels, desirable in various industries including automobile manufacturers.

Methods of producing continuously cast hot rolled high strength steel sheet products

The present invention provides steel sheet products having controlled compositions that are subjected to two-step annealing processes to produce sheet products having desirable microstructures and favorable mechanical properties such as high strength and ultra-high formability. Steels processed in accordance with the present invention exhibit combined ultimate tensile strength and total elongation (UTS&#xb7;TE) properties of greater than 25,000 MPa-%. Steels with these properties fall into the category of Generation 3 advanced high strength steels, and are highly desired by various industries including automobile manufacturers.

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New Castle, PA, United States of America

Matthew Michael McCosby