Thin Cast Strip Product with Microalloy Additions, and Method for Making the Same

A steel product or thin steel cast strip comprised of, by weight, less than 0.25% carbon, between 0.20 and 2.0% manganese, between 0.05 and 0.50% silicon, aluminum 0.008% or less by weight, and at least one element selected from the group consisting of titanium between about 0.01% and about 0.20%, niobium between about 0.01% and about 0.20%, molybdenum between about 0.05% and about 0.50%, and vanadium between about 0.01% and about 0.20%, and having a microstructure comprised of a majority bainite, and further comprising fine oxide particles of silicon and iron distributed through the steel microstructure having an average precipitate size less than 50 nanometers. The steel product or thin cast steel strip may have a yield strength of at least 55 ksi (380 MPa) or a tensile strength of at least 500 MPa, or both. The steel product or thin cast steel strip may have a total elongation of at least 6% or 10%. The thin cast steel strip may have thickness less than 3.0 mm, or less than 2.5 mm, or less than 2.0 mm.