Microstructure and two-body abrasive wear behavior of Fe-B surfacing alloys with different chromium and vanadium contents

To reduce the use of V in Fe-B surfacing alloy and retain the beneficial effect of V in improving crack resistance and wear resistance, the design idea of using Cr to replace V partially was proposed in this paper. Fe-B surfacing alloy layers with different Cr and V contents were prepared by plasma powder surfacing technology. The effects of Cr and V on microstructure and wear resistance of the surfacing layer were studied. The results show that the surfacing alloy layer is composed of primary crystal Fe2B, eutectic structure, and VB. The addition of Cr does not change the phase composition of the surfacing layer, but the Cr element will preferentially replace Fe atoms in Fe2B, reduce the content of V in Fe2B, and promote more V to participate in the precipitation of VB. Therefore, with the increase of Cr addition, the volume fraction of VB in the surfacing alloy layer increases, the size becomes larger, and the primary Fe2B has a clear trend of refinement. The results of the two-body abrasive wear test show that with the increase of Cr addition, a large number of VB phases that can resist abrasive cutting are separated from the surfacing alloy, which reduces the weight loss. Comprehensive analysis shows that Cr can partially replace V, promote the precipitation of high hardness VB phase, and effectively refine the primary crystal Fe2B, to improve the crack resistance and abrasive wear resistance of Fe-B surfacing alloy.