Vanadium Microalloyed Forging Steels

The production processing, microstructure and properties of vanadium microalloyed forging steels with medium-carbon are introduced. The strengthening produced by vanadium enhances the strength of medium-carbon steels. As a result, no further heat treatment is required for vanadium microalloyed forging steels. The increasing of strengths is due to fine vanadium carbonitride particles precipitating in ferrite-pearlite microstructure during cooling after forging. The highest strengths of steels are produced in base microstructrures with large volume fractions of pearlite. As a result, the resistance to cleavage fracture during impact loading is low. There are several available approaches for improving toughness. One approach is to lower the carbon content if lower strength can be tolerated. Another approach is to add titanium as a microalloying element. The third approach is to increasing sulfur content properly.