Investigation of the nitride phase in a heat-resistant alloy of the Ni – Co – W – Ti system, hardened by internal nitration

Abstract

In a high-temperature alloy of the Ni – Co – Cr – W – Ti system grade VZh171, using X-ray spectral analysis, scanning and transmission electron microscopy, the composition of the particles of the hardening phase — nitrides after internal nitriding and subsequent heat treatment was studied. It was found that the particles differ on it chemical composition: the main constituent element, titanium or chromium, is proportionally replaced by other alloy components. The nitride compositions near the surface and in the center of the sample differ in the titanium to chromium ratio. After annealing, this difference is smaller, and the chromium content also decreases. It was found that the nitrides formed during nitriding are compounds in which the main forming element, titanium or chromium, is proportionally replaced by other alloy components. The nitride compositions near the surface and in the center of the sample differ in the titanium to chromium ratio. After annealing, this difference is smaller, and the chromium content also decreases.