Abstract: A nitrided steel product or thin cast steel strip comprising, by weight, less than 0.25% carbon, between 0.20 and 2.0% manganese, between 0.05 and 0.50% silicon, less than 0.01% aluminum, niobium between 0.01 and about 0.20%, and between 0.01 and 0.075% nitrogen, and having a majority of the microstructure comprised of bainite and acicular ferrite, having more than 70% niobium in solid solution prior to nitriding and having after nitriding for one hour yield strength between 600 MPa and 800 MPa and tensile strength between 650 MPa and 900 MPa and no more than a 2% decrease in total elongation from the steel product prior to nitriding.

Abstract: A nitrided steel product or thin cast steel strip comprising, by weight, less than 0.25% carbon, between 0.20 and 2.0% manganese, between 0.05 and 0.50% silicon, less than 0.01% aluminum, niobium between 0.01 and about 0.20%, and between 0.01 and 0.075% nitrogen, and having a majority of the microstructure comprised of bainite and acicular ferrite, having more than 70% niobium in solid solution prior to nitriding and having yield strength between 650 MPa and 800 MPa and tensile strength between 750 MPa and 900 MPa.