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Description
Microalloying elements are of critical importance in the production of Thermo-Mechanically Processed (TMP) steels. Due to the high solubility of vanadium carbo-nitrides, V(CN), vanadium microalloying is suitable for a wide range of steels, ranging from ultra-low carbon automotive steels to medium carbon steels for forgings and reinforcing bar, high carbon rail steels and ultra-high carbon rod. The high solubility of V(CN) also allows the use of reduced reheating temperatures prior to rolling, giving significant energy savings. The strengthening effect of vanadium can be increased in certain steel types by using higher nitrogen levels; the synergistic combination of vanadium and nitrogen allows for reduced overall alloying additions. The use of higher strength vanadium containing steels has considerable environmental benefits, allowing for reduced amounts of steel to be used.
Vanadium resources are widely distributed around the world; China, Russia and South Africa are major producers, but new reserves are being exploited in other countries such as Australia. Vanadium production methods can be classified into three main categories, depending on the type of the vanadium reserve: vanadium produced as a co-product from steel production when appropriate iron ores are processed; vanadium produced by the processing of industrial waste such as spent catalysts; and vanadium produced from directly mined ore, such as magnetites rich in vanadium and titanium.
The suitability of vanadium for many steel types, the wide geographical distribution and varied production methods means that vanadium can be considered a robust and sustainable microalloying element.
As well as being of vital importance in TMP steels, vanadium is also a critical alloying element in advanced titanium alloys, and vanadium alloys are being considered for applications in nuclear fusion reactors.
Increased use of vanadium in high strength steels is predicted, and the growth of alternative applications will lead to increased vanadium demand worldwide.