摘要 |
A steel product or thin steel cast strip comprised of, by weight, less th an 0.25% carbon, between 0.20 and 2.0% manganese, between 0.05 and 0.50% sil icon, less than 0.01% aluminum, and at least one of niobium between 0.01% an d 0.20% and vanadium between 0.01% and 0.20%, and having a microstructure of a majority bainite and acicular ferrite, and more than 70% niobium and/or v anadium in solid solution. The steel product may have an increase in elongat ion and an increase in yield strength after age hardening. The age hardened steel product may have niobium carbonitride particles with an average partic le size of 10 nanometers and less, and may have substantially no niobium car bonitride particles greater than 50 nanometers. The steel product may have a yield strength of at least 380 MPa or a tensile strength of at least 410 MP a, or both. The steel product or thin cast steel strip may have a total elon gation of at least 6% or 10%. |