Vanadium Carbide

Chemical formula: VC

Melting point: 2810 °C

Density: 5.77 g/cm3

Scientific and industrial interest in vanadium carbide was consolidated in the 20th century, following the development of high-performance steels. Unlike carbides of Group 4 elements such as titanium or zirconium, which require separate synthesis from the carbothermic reduction of their oxides, vanadium carbide can be generated directly from molten steel. This is possible because vanadium has greater solubility in iron than other transition metals, allowing vanadium oxides or pure metal to be introduced directly into the molten bath. During the cooling and solidification process, vanadium exhibits a strong affinity for carbon and combines with it to form stable intergranular carbides, responsible for the characteristic hardening of steels alloyed with this element.

Vanadium carbide is metastable, meaning that, in its pure state, it can undergo crystalline transformations over time. However, this decomposition process is extremely slow, to the point of being considered negligible under industrial use conditions. Its corrosion resistance is high when found in its pure state, although its addition to steels does not significantly increase resistance to corrosive agents, but rather significantly improves hardness and toughness. This combination of properties makes it an essential component in advanced metallurgy, especially in tool steels and high-speed steels. One of its key advantages over other metal carbides is that it facilitates heat treatment of nominal carbon steels, allowing for more homogeneous and wear-resistant microstructures.

Vanadium carbide plays a key role in the manufacture of high-speed steels (HSS), where it is used as a reinforcement to increase the hardness and wear resistance of tools subjected to intensive stress. It is found in screwdrivers, pliers, saws, presses, drill bits, cutting blades, and lathes, among many other tools that require sharpness and mechanical strength at high working speeds. It is also used as a doping agent in surface coatings designed to improve the lifespan of metal parts. Although vanadium is more expensive than chromium, which partially limits its widespread use, its incorporation, even in small quantities, provides substantial improvements to steels, justifying its use in high-performance applications. Thus, vanadium carbide has established itself as an indispensable component in modern metallurgy, combining the exceptional hardness of refractory carbides with the versatility offered by its compatibility with iron.