Surface segregation in HAYNES 230 alloy

The surface segregation in the Ni-based alloy HAYNES 230 was studied by Auger Electron Spectroscopy and X-ray Photoelectron Spectroscopy between 400 and 1100 8C. The qualitative variations of the surface contents of S, P, W, Mo, N, Si, and Mn were determined as a function of annealing temperature and time. It was found that at 925 8C the maximum coverage of sulphur at the alloy surface is in the range 0.06–0.15 monolayers. Chromium evaporation from the HAYNES 230 surface under UHV conditions is clearly evidenced for annealing at 1100 8C.