Abstract: The invention relates to a bainite steel consisting of the following elements in weight %: C: 0.25-0.55 Si: 0.5-1.8 Mn: 0.8-3.8 Cr: 0.2-2.0 Ti: 0.0-0.1 Cu: 0.0-1.2 V: 0.0-0.5 Nb: 0.0-0.06 Al: 0.0-2.75 N: <0.004 P: <0.025 S: <0.025 and a method for manufacturing a bainite steel strip that comprises the step of cooling the coiled strip of such composition to ambient temperature, during which the bainite transformation takes place.

Abstract: A multi-track laser beam process for surface hardening a low-carbon and low manganese steel. The process includes providing cold rolled close annealed (CRCA) steel sheets having in weight percentage, C: 0.03-0.07, Mn: 0.15-0.25 or 1.4, S: 0.005-0.009, P: 0.009-0.014, Si: 0.005-0.02, Al: 0.04, V: 0.001, Nb: 0.001, and Ti: 0.002 and heating the surface of the steel sheet to an austenizing temperature using a multi-track laser beam, where, upon cooling, phase transformation of the initial microstructure to a harder dual phase structure occurs. The surface temperature of the steel sheet may be controlled based on a comparison of the on-line surface temperature effect with pre-stored data representing the desired surface temperature effect to eliminate any possibility of melting the sheet. The development of the desired microstructure of the sheet, including measurement of the hardness level and the fraction of different phases, may be periodically reviewed.

Abstract: The present disclosure discloses a method for heat treating an iron-carbon alloy. The method comprises acts of heating the iron-carbon alloy to a first pre-determined temperature at a pre-determined heating rate, holding the iron-carbon alloy at the first pre-determined temperature for a pre-set period of time. The method further comprises acts of cooling the iron-carbon alloy to a second pre-determined temperature at a pre-determined cooling rate and inducing magnetic field on the iron-carbon alloy selectively during at least one of heating and cooling of the iron-carbon alloy. The induction of magnetic field on the iron-carbon alloy results in microstructural changes to improve formation of pearlitic structure in the iron-carbon alloy.

Abstract: A process for producing dual phase steel sheet including steps of making a liquid steel having a chemical composition in wt % of C: 0.03-0.12. Mn: 0.8-1.5. Si: <0.1, Cr: 0.3-0.7, S: 0.008 maximum, P: 0.025 maximum, Al: 0.01 to 0.1, N: 0.007 maximum. Nb: 0.005-0.035. and V: 0.06 maximum, remainder Fe; continuous casting the liquid steel into a slab; hot rolling the slab into a hot rolled sheet at finish rolling temperature (FRT) 840±30 ° C.; cooling the hot rolled sheet on the run out table at a cooling rate 40 ?70° C./s to an intermediate temperature (Tint) of 720° C.?Tint?650° C.; natural cooling the hot rolled sheet for a duration of 5-7 seconds and rapidly cooling the hot rolled sheet to transform remaining carbon enriched austenite to martensite, at cooling rate of 40-70 ° C./s to a coiling temperature below 400° C.

Abstract: The present disclosure discloses a method for heat treating an iron-carbon alloy. The method comprises acts of heating the iron-carbon alloy to a first pre-determined temperature at a pre-determined heating rate, holding the iron-carbon alloy at the first pre-determined temperature for a pre-set period of time. The method further comprises acts of cooling the iron-carbon alloy to a second pre-determined temperature at a pre-determined cooling rate and inducing magnetic field on the iron-carbon alloy selectively during at least one of heating and cooling of the iron-carbon alloy. The induction of magnetic field on the iron-carbon alloy results in microstructural changes to improve formation of pearlitic structure in the iron-carbon alloy.

Abstract: A multi-track laser beam process for surface hardening a low-carbon and low manganese steel. The process includes providing cold rolled close annealed (CRCA) steel sheets having in weight percentage, C: 0.03-0.07, Mn: 0.15-0.25 or 1.4, S: 0.005-0.009, P: 0.009-0.014, Si: 0.005-0.02, Al: 0.04, V: 0.001, Nb: 0.001,and Ti: 0.002 and heating the surface of the steel sheet to an austenizing temperature using a multi-track laser beam, where, upon cooling, phase transformation of the initial microstructure to a harder dual phase structure occurs. The surface temperature of the steel sheet may be controlled based on a comparison of the on-line surface temperature effect with pre-stored data representing the desired surface temperature effect to eliminate any possibility of melting the sheet. The development of the desired microstructure of the sheet, including measurement of the hardness level and the fraction of different phases, may be periodically reviewed.

Abstract: The invention relates to a bainite steel consisting of the following elements in weight %: C: 0.25-0.55 Si: 0.5-1.8 Mn: 0.8-3.8 Cr: 0.2-2.0 Ti: 0.0-0.1 Cu: 0.0-1.2 V: 0.0-0.5 Nb: 0.0-0.06 Al: 0.0-2.75 N: <0.004 P: <0.025 S: <0.025 and a method for manufacturing a bainite steel strip that comprises the step of cooling the coiled strip of such composition to ambient temperature, during which the bainite transformation takes place.