Effect of vanadium alloying on microstructure and wear behavior of two-body abrasive particles of Fe–5.5 wt% B surfacing alloy

Abstract

The effects of vanadium addition on the microstructure and two-body abrasive wear behavior of an Fe–5.5 wt.% B surfacing alloy prepared by the plasma arc welding technique were investigated. The results show that the Fe–5.5 wt.% B surfacing alloys with different contents of vanadium are mainly composed of the primary Fe 2 B phase, Fe 2 B+Fe eutectic structure, and a vanadium boride (VB) precipitate. With increasing vanadium content in the Fe–5.5 wt.% B surfacing alloys, the number of microcracks in the primary Fe 2 B phase decreases, and the microcracks finally disappear, while the volume fraction of VB increases concurrently. The primary Fe 2 B phase can be remarkably refined, and the growth orientation changes from preferential to disordered staggered growth. The hardness of the surfacing alloy shows a trend of initial increase and subsequent decrease. Meanwhile, the wear resistance of the two bodies shows a continuous increasing trend, and the change trend is the same under contact loads of 24 N and 48 N. Alloying element V can effectively refine the primary Fe 2 B, promote the precipitation of VB, and form a microstructure reinforced by fine interlaced rod-shaped Fe 2 B and spherical VB, which effectively improves the crack resistance and wear resistance of the surfacing alloy.