The microalloying elements V, Nb and Ti are commonly used to improve the properties of HSLA steels. Of these three microalloying elements, the carbides and nitrides of V have the highest solubility, and this influences the steel types in which V is used, and how they are processed.
This paper will review the use of V in HSLA steels and give recent examples of how the high solubility of V carbides and nitrides is utilised in a range of steel types. V additions are well suited to medium and high carbon steels, as the high solubility of V carbo-nitrides, V(C,N), enables the formation of the fine precipitates necessary for precipitation strengthening.
In concrete reinforcing bar, V(C,N) precipitation strengthening allows high strengths to be obtained combined with weldability and high ductility for use in seismic zones. In direct forging steels, V additions enable costly quench and temper heat treatments to be eliminated, and in bainitic forgings, increased hardenability allows improved properties to be achieved over a wider section size.
Ferro-Alloy Resources Ltd (LON:FAR) is developing the giant Balasausqandiq vanadium deposit in Kyzylordinskaya oblast of southern Kazakhstan. The ore at this deposit is unlike that of nearly all other primary vanadium deposits and is capable of being treated by a much lower cost process.