Oxidation Resistance of “Ni-Cr-Si-B-Alloy + Nb + B” Protective Layers, Produced by Non-Vacuum Electron Beam Cladding Technique

Abstract

The aim of this investigation was to study the influence of Nb-enriched powder mixtures on structure and oxidation resistance of protective layers based on Ni-based self-fluxing alloy, produced by non-vacuum electron beam cladding technique on low-carbon steel substrates. The oxidation resistance of coatings was studied by thermogravimetric analysis (TGA). The samples held at 900°C for two hours in air atmosphere. TGA results indicate that the highest oxidation resistance has the material, obtained by cladding of pure Ni-based self-fluxing alloy. Samples, produced by cladding of Ni-based self-fluxing alloy in combination with Nb-enriched powder mixtures demonstrate lower level of oxidation resistance. Structure of the coatings was characterized by optical and scanning electron microscopy combined with electron microprobe analysis as well as X-ray diffraction.