Abstract: A hot rolled steel sheet having a composition including the following elements, 0.18%?Carbon?0.3%, 1.8%?Manganese?4.5%. 0.8%?Silicon?2%,0 001%?Aluminum ?0.2%, 0.1%?Molybdenum?1%, 0.001%?Titanium?0.2%, 0.0001%?Boron?0.01%, 0%?Phosphorus?0.09%, 0%?Sulfur?0.09%.,0%?Nitrogen?0.09%, 0%?Chromium?0.5%, 0%?Niobium?0.1%, 0%?Vanadium?0.5%, 0%?Nickel?1%, 0%?Copper?1%, 0%?Calcium?0.005%, 0%?Magnesium?0.0010% the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet including in area fraction, of at least 70% martensite, 8% to 25% residual austenite, wherein the shape factor of the residual austenite is between 4 and 12.

Abstract: A hot rolled steel having a composition including the following elements, expressed in percentage by weight: 15%?Nickel?25% 6%?Cobalt?12% 2%?Molybdenum?6% 0.1%?Titanium?1% 0.0001%?Carbon?0.03% 0.002%?Phosphorus?0.02% 0%?Sulfur?0.005%. 0 %?Nitrogen?0.01% and can contain one or more of the following optional elements 0%?Aluminum?0.1% 0%?Niobium?0.1% 0%?Vanadium?0.3% 0%?Copper?0.5% 0%?Chromium?0.5% the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 20% to 40% Tempered Martensite, at least 60% of Reverted Austenite and inter-metallic compounds of Molybdenum, Titanium and Nickel.

Abstract: A hot rolled steel product having a composition including in percentage by weight: 0.06%?C?0.18%, 0.01%?Ni?0.6%, 0.001%?Cu?2%, 0.001%?Cr?2%, 0.001%?Si?0.8%, 0%?N?0.008%, 0%?P?0.03%, 0%?S?0.03%, 0.001%?Mo?0.5%, 0.001%?Nb?0.1%, 0.001%?V?0.5%, 0.001%?Ti?0.1% and one or more following optional elements 0.2%?Mn?2%, 0.005%?Al?0.1%, 0%?B?0.003%, 0%?Ca?0.01%, 0%?Mg?0.010% the remainder composition being composed of iron and unavoidable impurities caused by processing, such product having a tertiary scale layer including, in area fraction, a total amount of at least 50% of magnetite and ferrite wherein ferrite is at least 25%, 0% to 50% of wustite, and 0% to 10% of hematite, such scale layer having a thickness between 5 microns and 40 microns.

Abstract: The invention relates to a cold-rolled and annealed Dual-Phase steel sheet having a strength between 980 and 1100 MPa, and a breaking elongation greater than 9%, of which the composition comprises, the contents being expressed by weight: 0.055%?C?0.095%, 2%?Mn?2.6%, 0.005%?Si?0.35%, S?0.005%, P?0.050%, 0.1?Al?0.3%, 0.05%?Mo?0.25%, 0.2%?Cr?0.5%, it being understood that Cr+2Mo?0.6%, Ni?0.1%, 0.010?Nb?0.040%, 0.010?Ti?0.050%, 0.0005?B?0.0025%, and 0.002%?N?0.007%, the remainder of the composition consisting of iron and the inevitable impurities resulting from the smelting.