Abstract: A method is provided for the manufacture of steel steel strip having high strength and high ductility. The method includes hot rolling steel consisting essentially of in weight percent C 0.05/0.20, Mn 3.0/8.0, Si less than 0.5, Al less than 0.1, the balance Fe and inevitable impurities at a minimum finishing temperature of Ar1+50 C, cooling the hot rolled steel strip at a rate sufficient to ensure that the microstructure of the strip consists of greater than 50 percent by volume of martensite, and then annealing the steel strip at a temperature within the range of Ac1 to Ac1+50° C. for a minimum time at temperature of one hour. The steel has a microstructure after annealing that consists essentially of ferrite and retained austenite.

Abstract: A method for producing steel line pipe having low yield strength to tensile strength ratio in order to improve the capability of steel line pipe to undergo reeling into coil form and unreeling therefrom. The method includes (a) providing a steel pipe having a composition consisting essentially of in weight percent: C 0.01 to 0.40, Mn 0.25 to 2.0, P residual to less than 0.5, S residual to less than 0.020, Si residual to 2.0, Cu residual to 1.0, Ni residual to 1.0, Cr residual to 2.0, Mo residual to 1.0, Al 0.010 minimum to less than 1.0, N residual to 0.030, V residual to less than 0.5, B residual to less than 0.02, Ti residual to less than 0.3, and Nb residual to less than 0.3, balance iron and incidental impurities.