Effect of Vanadium Content on Microstructure and Wear Behavior of Fe-Cr-Mn-C Surfacing Alloys

To address the brittleness issue inherent in Fe-Cr-C wear-resistant surfacing alloys and enhance their wear resistance, this study comprehensively investigates the influence of vanadium on the microstructure, impact toughness, and wear performance of Fe-Cr-Mn-C alloys. Employing an array of characterization techniques, including metallographic microscope (OM), x-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, impact testing, hardness testing, and abrasive wear testing, this research delineates the role of vanadium addition. The experimental results reveal that vanadium modifies the microstructural features of the alloys. A minor addition of vanadium preferentially dissolves in the primary M₇C₃ carbides, whereas a higher concentration of vanadium fosters the crystallization of these primary carbides and the formation of secondary hard particles, notably VC, thereby refining the carbide grains. The impact toughness exhibits a nonlinear response to increasing vanadium content, initially decreasing, and then subsequently improving. Notably, the alloy with 14.11 wt.% Mn and 7.11 wt.% V achieves the peak impact toughness at 30.00 J/cm². Further, the analyses of hardness and two-body abrasive wear indicate a similar trend: performance deteriorates initially with the addition of vanadium but improves with higher concentrations. The optimal mechanical properties are attained when the alloy composition includes 14.11 wt.% Mn and 7.11 wt.% V, where the hardness reaches up to 55.9 HRC and the wear loss under a 24 N load is minimized to 30.6 mg. This study underscores the nuanced effects of vanadium in enhancing the durability and mechanical robustness of Fe-Cr-Mn-C surfacing alloys.