Effect of Y2O3 on the microstructure and properties of Fe-Cr-C-B weld overlay

The three main forms of mechanical parts failure are wear, corrosion and fatigue, and the energy consumption and economic losses caused by wear are very huge, In this paper, Fe-Cr-C-B-Ti-Y wear-resistant surfacing layer was prepared by plasma surfacing. The wear resistance of the surfacing layer was measured by MLS-23 rubber wheel wet sand wear tester. The phase composition and microstructure of the surfacing layer were analyzed by X-ray diffraction ( XRD ), scanning electron microscopy ( SEM ) and transmission electron microscopy ( TEM ), and the strengthening mechanism and wear energy mechanism of the alloy were studied. The results show that the microstructure components of Fe-Cr-C-B-Ti-Y surfacing layer are austenite γ-Fe, M₂₃ ( C, B ) ₆ eutectic carbide and TiC hard phase. With the increase of Y content, the hardness and wear weight loss of the surfacing layer show a change of ' first increase and then decrease '. When the Y content is 0.4 %, the precipitation content of TiC hard phase and M₂₃ ( C, B ) ₆ eutectic carbide is the most, the grain size is the smallest, the surfacing layer is the best, and the wetting angle is the smallest, only 52.2 °.At this time, the Rockwell hardness of the surfacing layer reaches 89.7 HRC, and the wear weight loss is 0.27 g. The wear energy mechanism of the surfacing layer is mainly abrasive wear, and the material removal method is mainly micro-cutting and furrow wear.