Influence of Y Nano-Oxide and Its Secondary Phase on Microstructure, Mechanical Properties, and Wear Behavior of the Stainless Steel Coatings Fabricated by Plasma Transfer Arc

Abstract

Rare-earth is an efficient refiner for surface modification of steel material. This study presents the synergistic influence of Y2O3 nanoparticles (YNPs) and Mn-oxide secondary phase on the microstructure and mechanical properties of 14CrSiMnV coating fabricated by plasma transfer arc cladding process. The results indicated that the residual Y accumulated with Mn, forming a secondary phase oxide particle instead of inclusions or slags during rapid cooling solidification of the coating. Due to enlarged equiaxed grains, declining long-range dendritic grains, and secondary phase strengthening, steel coatings present hybrid-type fracture mechanism, less plastic deformation, and third-body interaction. With an optimal addition of YNPs (0.4 wt.%), the mechanical properties of the steel coating are improved, as indicated by the increase of 92.0% in the tensile strength, increase of 55.6% in the elongation, increase of 11.3% in the microhardness, decrease of 22.2% in wear weight loss, and increase of 28.3% in relative wear resistance.