DENDRITIC SEGREGATION IN HEAT-RESISTANT NICKEL-ALLOY

The influence of the smelting of electrode ingots (made of heat-resist ant nickel alloy, diameter 85 mm) using vacuum are, electroslag, elect ron-beam, and vacuum are two-electrode smelting, as well as moderate-a nd high-temperature isostatic treatment of the ingots, on the dendriti c segregation of boron and carbon in the heat-resistant nickel alloy N i-5 Al-2 Ti-9 Cr-16 Co-6 W-4 Mo-3 Nb-Hf-C-B is studied by track and ac tivation autoradiography, metallographic analysis, and X-ray spectral microanalysis, Laws governing the influence of the smelting conditions on the dispersity of the dendritic structure and the development of d endritic segregation are established. A mechanism describing the influ ence of the smelting conditions on the segregation is proposed.