Abstract: A hot rolled steel sheet having a composition including of the following elements 0.060%?Carbon?0.1%, 1.4%?Manganese?1.8%, 0.3%?Silicon?0.8%, 0.01%?Aluminum?0.1%, 0.01%?Niobium?0.09%, 0.01%?Titanium?0.09%, 0.002%?Phosphorus?0.02%, 0%?Sulfur?0.005%, 0%?Nitrogen?0.01%, with 0.045%?Ti+Nb?0.060%, 0%?Chromium?0.5%, 0%?Molybdenum?0.4%, 0%?Vanadium?0.4%, 0%?Calcium?0.005%, 0%?Copper?1%, 0%?Nickel?1%, 0%?Boron?0.05%, 0%?Magnesium?0.05%, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet including in area fraction, 10% to 20% Bainite, 80% to 92% Ferrite wherein the aspect ratio of the grains of Bainite and Ferrite is less than 1.75 and a cumulated amount of Residual Austenite and Martensite is from 0% to 10%.

Abstract: A coated dual-phase steel and process for producing the coated dual-phase steel is provided. The process includes providing a steel slab with a desired chemistry, soaking the slab at an elevated temperature and then hot rolling the slab to produce hot-rolled strip. The hot-rolled strip is coiled and has a ferrite-pearlite microstructure. The coiled hot-rolled strip is cold-rolled into cold-rolled sheet with at least a 60% reduction in thickness compared to the thickness of the coiled hot-rolled strip. The cold-rolled sheet is subjected to an intercritical anneal followed by rapid cooling with the absence of an isothermal heat treatment or hold after rapid cooling near the molten metal pot temperature—during which, before or after which the steel is coated. The coated steel sheet has a dual-phase ferrite-martensite microstructure, a yield strength of at least 310 MPa, a tensile strength of at least 580 MPa and a total elongation to failure of at least 18%.

Abstract: Dual-phase steels and a process for producing a family of dual-phase steels that have a low YS/TS ratio and tensile strength above 590 MPa. The process includes employing low annealing temperatures combined with specific cooling strategies using gas jet rapid cooling equipped with “Ultra Rapid Cooling” (URC) capacity in the cooling tower. The process can also include the production of dual-phase steels with tensile strengths of at least 690 MPa by processing steels with specific cooling strategies using the URC having a refined Mo content towards the higher end of the chemical composition range mentioned in the current stated invention.

Abstract: A coated dual-phase steel and process for producing the coated dual-phase steel is provided. The process includes providing a steel slab with a desired chemistry, soaking the slab at an elevated temperature and then hot rolling the slab to produce hot-rolled strip. The hot-rolled strip is coiled and has a ferrite-pearlite microstructure. The coiled hot-rolled strip is cold-rolled into cold-rolled sheet with at least a 60% reduction in thickness compared to the thickness of the coiled hot-rolled strip. The cold-rolled sheet is subjected to an intercritical anneal followed by rapid cooling with the absence of an isothermal heat treatment or hold after rapid cooling near the molten metal pot temperature—during which, before or after which the steel is coated. The coated steel sheet has a dual-phase ferrite-martensite microstructure, a yield strength of at least 310 MPa, a tensile strength of at least 580 MPa and a total elongation to failure of at least 18%.

Abstract: Dual-phase steels and a process for producing a family of dual-phase steels that have a low YS/TS ratio and tensile strength above 590 MPa. The process includes employing low annealing temperatures combined with specific cooling strategies using gas jet rapid cooling equipped with “Ultra Rapid Cooling” (URC) capacity in the cooling tower. The process can also include the production of dual-phase steels with tensile strengths of at least 690 MPa by processing steels with specific cooling strategies using the URC having a refined Mo content towards the higher end of the chemical composition range mentioned in the current stated invention.