SURFACE SEGREGATION IN AN ENGINEERING ALLOY - HASTELLOY C-276

We have examined the surface composition of a cold-worked nickel-base superalloy, HASTELLOY C-276, by Auger electron spectroscopy. The alloy was subjected to annealing cycles at temperatures between 100 and 900°C. A number of elements, including C, N, O, P, S, and Si, segregated to the sample surface. The segregation behavior appears to be quite complex. Yet it can be understood in terms of five fundamental effects: kinetic limitations, thermodynamic temperature effects, cold-work annealing, depletion of trace impurities, and solute interactions. © 1979 The Metallurgical of Society of AIME.