| 摘要 |
<p>This invention relates to a high strength hot rolled steel sheet with an excellent combination of tensile strength of at least 550 MPa and formability, comprising in weight percent at most 0.15% of C at most 0.5% of Si between 0.5 and 2.0% of Mn at most 0.06% of P at most 0.008% of S at most 0.1% of Al_sol at most 0.02% of N between 0.02 and 0.45% of V between 0.05 and 0.7% of Mo optionally between 0.01 and 0.1% of Nb balance of Fe and inevitable impurities, wherein the steel sheet has a precipitation strengthened and substantially single-phase ferritic microstructure, wherein the volume fraction of the ferrite phase in said microstructure is not lower than 97%, and wherein the precipitates in said microstructure comprise fine precipitates of composite carbides containing Mo and V and optionally Nb.</p> |
