Influence of vanadium and nitrogen on the structure formation and properties of K60 (X70) rolled steel coils

Resumo

The production of microalloyed steel coils (thickness 8 mm) of strength category K60 (X70) with requirements on the low-temperature strength is studied in industrial trials. Microalloying of the steel with 0.10% V and 0.020% N and controlled rolling in the casting and rolling system, with a final deformation temperature of 800°C, results in the production of metal with high strength (σ_B ≥ 600 N/mm², σ_y ≥ 520 N/mm²) and plasticity (δ₅ = 28%) with satisfactory strength at –40°C according to impact-flexure and drop tests.