Abstract: The present invention provides a method for the fabrication of a steel sheet with a completely martensitic structure which has an average lath size of less than 1 micrometer and an average elongation factor of the laths is between 2 and 5. The elongation factor of a lath is defined as a maximum dimension lmax divided by and a minimum dimension lmin. The steel sheet has a yield stress greater than 1300 MPa and a mechanical strength greater than (3220(C)+958) megapascals. A composition of a semi-finished steel product includes, expressed in percent by weight, is, 0.15%?C?0.40%, 1.5%?Mn?3%, 0.005%?Si?2%, 0.005%?Al?0.1%, 1.8%?Cr?4%, 0%?Mo?2%, whereby: 2.7% 0.5 (Mn)+(Cr)+3(Mo)?5.7%, S?0.05%, P?0.1%, optionally: 0%?Nb?0.050%, 0.01%?Ti?0.1%, 0.0005%?B?0.005%, 0.0005%?Ca?0.005%. The semi-finished product is reheated to a temperature T1 in the range between 1050° C. and 1250° C., then subjected to a roughing rolling at a temperature T2 in the range between 1000 and 880° C.

Abstract: A steel plate, the chemical composition of which includes, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?31, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: The present invention provides a method for the fabrication of a steel sheet with a completely martensitic structure which has an average lath size of less than 1 micrometer and an average elongation factor of the laths is between 2 and 5. The elongation factor of a lath is defined as a maximum dimension lmax divided by and a minimum dimension lmin. The steel sheet has a yield stress greater than 1300 MPa and a mechanical strength greater than (3220(C)+958) megapascals. A composition of a semi-finished steel product includes, expressed in percent by weight, is, 0.15%?C?0.40%, 1.5%?Mn?3%, 0.005%?Si?2%, 0.005%?Al?0.1%, 1.8%?Cr?4%, 0%?Mo?2%, whereby: 2.7% 0.5 (Mn)+(Cr)+3(Mo)?5.7%, S?0.05%, P?0.1%, optionally: 0%?Nb?0.050%, 0.01%?Ti?0.1%, 0.0005%?B?0.005%, 0.0005%?Ca?0.005%. The semi-finished product is reheated to a temperature T1 in the range between 1050° C. and 1250° C., then subjected to a roughing rolling at a temperature T2 in the range between 1000 and 880° C.

Abstract: The present invention provides a method for the fabrication of a steel sheet with a completely martensitic structure which has an average lath size of less than 1 micrometer and an average elongation factor of the laths is between 2 and 5. The elongation factor of a lath is defined as a maximum dimension 1max divided by and a minimum dimension 1max. The steel sheet has a yield stress greater than 1300 MPa and a mechanical strength greater than (3220(C)+958) megapascals. A composition of a semi-finished steel product includes, expressed in percent by weight, is, 0.15%?C?0.40%, 1.5%?Mn?3%, 0.005%?Si?2%, 0.005%?Al?0.1%, 1.8%?Cr?4%, 0%?Mo?2%, whereby: 2.7%?0.5 (Mn)+(Cr)+3(Mo)?5.7%, S?0.05%, P?0.1%, optionally: 0%?Nb?0.050%, 0.01%?Ti?0.1%, 0.0005%?B?0.005%, 0.0005%?Ca?0.005%. The semi-finished product is reheated to a temperature T1 in the range between 1050° C. and 1250° C., then subjected to a roughing rolling at a temperature T2 in the range between 1000 and 880° C.

Abstract: The present invention provides a method for the fabrication of a martensitic steel sheet with a yield stress greater than 1300 MPa. The method includes the steps of obtaining a semi-finished steel product, the composition of which includes, whereby the contents are expressed in percent by weight: 0.15%?C?0.40%, 1.5%?Mn?3%, 0.005%?Si?2%, 0.005%?Al?0.1%, S?0.05%, P?0.1%, 0.025%?Nb?0.1%, and optionally: 0.01%?Ti?0.1%, 0%?Cr?4%, 0%?Mo?2%, 0.0005%?B?0.005%, 0.0005%?Ca?0.005%. The remainder of the composition is iron and the inevitable impurities resulting from processing. The semi-finished product is reheated to a temperature T1 in the range between 1050° C. and 1250° C., then the reheated semi-finished product is subjected to a roughing rolling at a temperature T2 in the range between 1050 and 1150° C.

Abstract: A steel plate, the chemical composition of which includes, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?31, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: A cold-rolled and annealed ferritic steel sheet is provided. The steel has a composition comprising, expressed by weight: 0.001?C?0.15%; Mn?1%; Si?1.5%; 7.5%?AI?10%; 0.020%?Ti?0.5%; S?0.050%; and P?0.1%. A balance of the composition includes iron and inevitable impurities resulting from the smelting. The structure includes kappa (?) precipitates and equiaxed ferrite, an average grain size d? of the equiaxed ferrite is less than 50 microns, and a linear fraction f of intergranular ? precipitates is less than 30%. The linear fraction f is defined by f = ? ( A ) ? di ? ( A ) ? Li . ?(A)di denotes the total length of grain boundaries containing ? precipitates relative to an area (A) and ?(A)Li denotes the total length of the grain boundaries relative to the area (A). A content of carbon in solid solution is less than 0.005% by weight, and the cold-rolled and annealed ferritic steel sheet has a thickness between 0.6 mm and 1.5 mm.

Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: A rolled steel sheet or blank is provided, the composition of which comprises the elements listed below in percent by weight: C?0.1%; 0.5%?Mn?7%; 0.5%?Si?3.5%; 0.5%<Ti?2%; 2%<Ni?7%; Al?0.10%; Cr?2%; Cu?2%; Co?2%; Mo?2%; S?0.005%; P?0.03%; Nb?0.1%; V?0.1%; B<0.005%; N?0.008%, and the silicon and titanium contents are such that: Si + Ti ? 2.5 ? % , Ti Si ? 0.3 the remainder of the composition consisting of iron and unavoidable impurities resulting from processing. A method for the fabrication of a part for a land motor vehicle from the sheet or blank by hot stamping is also provided. The microstructure of the part consisting essentially of martensite and intermetallic precipitates of type Fe2TiSi with an area percentage between 1 and 5% intermetallic precipitates.

Abstract: A cold-rolled and annealed ferritic steel sheet is provided. The steel has a composition comprising, expressed by weight: 0.001?C?0.15%; Mn?1%; Si?1.5%; 7.5%?AI?10%; 0.020%?Ti?0.5%; S?0.050%; and P?0.1%. A balance of the composition includes iron and inevitable impurities resulting from the smelting. The structure includes kappa (?) precipitates and equiaxed ferrite, an average grain size d? of the equiaxed ferrite is less than 50 microns, and a linear fraction f of intergranular ? precipitates is less than 30%. The linear fraction f is defined by f = ? ( A ) ? di ? ( A ) ? Li . ?(A)di denotes the total length of grain boundaries containing ? precipitates relative to an area (A) and ?(A)Li denotes the total length of the grain boundaries relative to the area (A). A content of carbon in solid solution is less than 0.005% by weight, and the cold-rolled and annealed ferritic steel sheet has a thickness between 0.6 mm and 1.5 mm.

Abstract: The invention relates to a hot-rolled ferritic steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.001?C?0.15%, Mn?1%, Si?1.5%, 6%?Al?10%, 0.020%?Ti?0.5%, S?0.050%, P?0.1%, and, optionally, one or more elements chosen from: Cr?1%, Mo?1%, Ni?1%, Nb?0.1%, V?0.2%, B?0.010%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the average ferrite grain size dIV measured on a surface perpendicular to the transverse direction with respect to the rolling being less than 100 microns.

Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: A rolled steel sheet or blank is provided, the composition of which comprises the elements listed below in per cent by weight: C?0.1%; 0.5%?Mn?7%; 0.5%?Si?3.5%; 0.5%<Ti?2%; 2%<Ni?7%; Al?0.10%; Cr?2%; Cu?2%; Co?2%; Mo?2%; S?0.005%; P?0.03%; Nb?0.1%; V?0.1%; B<0.005%; N?0.008%, and the silicon and titanium contents are such that: Si + Ti ? 2.5 ? % , Ti Si ? 0.3 the remainder of the composition consisting of iron and unavoidable impurities resulting from processing. A method for the fabrication of a part for a land motor vehicle from the sheet or blank by hot stamping is also provided. The microstructure of the part consisting essentially of martensite and intermetallic precipitates of type Fe2TiSi with an area percentage between 1 and 5% intermetallic precipitates.

Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: The present invention provides a method for the fabrication of a martensitic steel sheet with a yield stress greater than 1300 MPa. The method includes the steps of obtaining a semi-finished steel product, the composition of which includes, whereby the contents are expressed in percent by weight: 0.15%?C?0.40%, 1.5%?Mn?3%, 0.005%?Si?2%, 0.005%?Al?0.1%, S?0.05%, P?0.1%, 0.025%?Nb?0.1%, and optionally: 0.01%?Ti?0.1%, 0%?Cr?4%, 0%?Mo?2%, 0.0005%?B?0.005%, 0.0005%?Ca?0.005%. The remainder of the composition is iron and the inevitable impurities resulting from processing. The semi-finished product is reheated to a temperature T1 in the range between 1050° C. and 1250° C., then the reheated semi-finished product is subjected to a roughing rolling at a temperature T2 in the range between 1050 and 1150° C.

Abstract: The present invention provides a method for the fabrication of a steel sheet with a completely martensitic structure which has an average lath size of less than 1 micrometer and an average elongation factor of the laths is between 2 and 5. The elongation factor of a lath is defined as a maximum dimension divided by and a minimum dimension 1max. The steel sheet has a yield stress greater than 1300 MPa and a mechanical strength greater than (3220(C)+958) megapascals. A composition of a semi-finished steel product includes, expressed in percent by weight, is, 0.15%?C?0.40%, 1.5%?Mn?3%, 0.005%?Si?2%, 0.005%?Al?0.1%, 1.8%?Cr?4%, 0%?Mo?2%, whereby: 2.7%?0.5 (Mn)+(Cr)+3(Mo)?5.7%, S?0.05%, P?0.1%, optionally: 0%?Nb?0.050%, 0.01%?Ti?0.1%, 0.0005%?B?0.005%, 0.0005%?Ca?0.005%. The semi-finished product is reheated to a temperature T1 in the range between 1050° C. and 1250° C., then subjected to a roughing rolling at a temperature T2 in the range between 1000 and 880° C.

Abstract: The invention relates to a steel plate, the chemical composition of which comprises, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?3%, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: The invention relates to a hot-rolled ferritic steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.001?C?0.15%, Mn?1%, Si?1.5%, 6%?Al?10%, 0.020%?Ti?0.5%, S?0.050%, P?0.1%, and, optionally, one or more elements chosen from: Cr?1%, Mo?1%, Ni?1%, Nb?0.1%, V?0.2%, B?0.010%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the average ferrite grain size dIV measured on a surface perpendicular to the transverse direction with respect to the rolling being less than 100 microns.

Abstract: The invention concerns a sandwich-type metal sheet (2), adapted to a forming and welding operation, and exhibiting excellent resistance at high temperatures, comprising two metal sheet facings (1, 1?) having a melting point Tp, and a metallic core (4) having a melting point Ta, Ta capable of being equal to or different from Tp, whereby the core (4) has a density lower than the density of each of the facings (1, 1?), and the core (4) and each of the facings (1, 1?) are mutually bound by means of a metallic binding agent (3, 3?) having a melting point Tm lower than Ta and Tp. The invention also concerns a method for making said sandwich-type metal sheet (2), and its use in the automotive industry.