Study on the Phase Analysis of Vanadium in Steel

In order to establish a method of phase analysis of vanadium, a study has been made of the chemical behavior of vanadium compounds synthesized. Extraction of vanadium compounds from steel was satisfactorily carried out in cold HCl; the extract was found to be almost carbonitride by an X-ray diffraction technique. Electron microscopic observation proved the existence of very fine precipitates of vanadium compounds (smaller than 0.3 μ). A recommended procedure for a phase analysis of vanadium in steel is as follows: The sample is decomposed in cold HCl at room temperature. The residue (acid insoluble vanadium fraction) is filtered and treated with HClO4-H2O2, and then vanadium as carbonitride is determined from the solution and vanadium as nitride from the insoluble residue. The experimental results showed that more than a half of vanadium in steel was solid soluble one which belonged to the acid soluble vanadium fraction, and that the acid insoluble vanadium fraction consisted mainly of carbonitride. Small amounts of nitride and oxide were also recognized.