Synthesis and Characterization of Fe2MoO4 as a Precursor Material for Mo Alloying in Steel

Iron molybdate (Fe₂MoO₄) has been studied as a new potential precursor for Mo additions in high alloy steel processing. Fe₂MoO₄ was synthesized by high temperature reactions between MoO₃, FeO_x and carbon by holding the mixture first for 23 hours at 873 K and then for 16 hours at 1373 K. The Fe₂MoO₄ syntheses were carried out with pure reagents as well as commercial grade materials supplied by steel industry. A thermodynamic analysis of the stabilities of the various phases in the Fe‐Mo‐O‐C quaternary was carried out. The synthesis processes, leading to the Fe₂MoO₄ formation from the precursors and further reduction by carbon were studied with the aid of thermogravimetric analysis (TGA), high‐temperature X‐ray diffraction (HT‐XRD) and evolved gas analysis by gas chromatography (GC). The maximum temperature in the case of all the experiments was 1373 K. It was found that the reactions between the precursor components start already above 873 K. The precursor mixture from commercial grade materials offers an economically advantageous process route with high Mo yield in steel.