Vanadium-aluminum-nitrogen steel

Residual Elements. In addition to carbon, manganese, phosphoms, sulfur, and silicon which are always present, carbon steels may contain small amounts of hydrogen, oxygen, or nitrogen, introduced during the steelmaking process nickel, copper, molybdenum, chromium, and tin, which may be present in the scrap and aluminum, titanium, vanadium, or zirconium, which may have been introduced during deoxidation. 

In practice, the production of vanadium by aluminothermic reduction is also governed by some other considerations. The reduction has to be carried out under an inert atmosphere (helium or argon) to avoid nitrogen pick-up from the air by vanadium metal. The composition of the oxide-aluminum charge has to be so chosen that the thermit (metal obtained by aluminothermic reduction) contains between 11 and 19% aluminum. This is necessary for the subsequent refining step in the vanadium metal production flowsheet. Pure vanadium pentoxide and pure aluminum are used as the starting materials, and the reduction is conducted in a closed steel bomb as shown in Figure 4.17 (C). 

Emission spectroscopy with arc and spark excitation has been used since the 1930s for many industrial analyses. In metaUurgy, for example, the presence in iron and steel of the elements nickel, chromium, sihcon, manganese, molybdenum, copper, aluminum, arsenic, tin, cobalt, vanadium, lead, titanium, phosphoms, and bismuth have been determined on a routine basis. Modem instruments can also measure oxygen, nitrogen, and carbon in metals, which used to require separate measurements with dedicated high-temperature... 

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