Thermal- and wear-resistant alloy arc welding depositions using composite and flux-cored wires with TiN, TiCN, and WC nanoparticles

Abstract

The studied GMAW processes – splitting the electrode into two wires, oscillation of the electrode, and cooling the weld pool metal with filler wire – reduce the arc thermal impact on the nanoparticles and improve their mass transfer into the solidifying metal. The nanoparticles in the wire fillers are recommended to be within 0.3–0.6 wt.%. Surfacing with two composite wires containing WC nanoparticles improves the properties of metal with a Ni3 Al-based matrix at temperatures within 1000–1200 °C. WC particles influence the composite metal formation, initiating precipitation from the γ+γ' solid solutions of strengthening phases in the form of intermetallides of (Zr,Ta,W)C type and ZrC carbides. The surfacing process with oscillation of the electrode flux-cored wire with TiCN particles improves the thermal and plastic resistance of the metal, with a matrix of the C–Fe–Cr–Ni–Mo–Ti–N system at temperatures within 750–950 °C. The composite metal with fine grains is formed under the influence of nucleation centres, in the form of TiCN nanoparticle clusters. The filler flux-cored wire with ultra-disperse TiN particles introduced in the weld pool, improves the resistance of deposited metal of the Fe–C–Cr–Mo–Ni–B system to abrasive wear at 500 °C. TiN particles initiate precipitation from the deposited metal matrix of strengthening phases in the form of (Ti, Mo)C 1−х carbides that are 1–4 μm in size. In conjunction with additional cooling of the melt near the solidification front, this helps to form the MMC structure in the melt.