Mechanical properties and precipitation behavior of high strength hot-rolled ferritic steel containing Nb and V

The mechanical properties and precipitation behavior of hot-rolled microalloyed steels with varied Nb and V additions were investigated. The steels had a predominantly ferritic microstructure with a very good combination of strength ( σ U T S  = 800–1000 MPa), ductility (total elongation = 16–19%) and hole expansion ratio (32–34%). The strength increased with increasing Nb and V content. The stretch-flangeability of the steels did not …