Experimental analysis and computer-based simulation of nitridation of Ni-base alloys—the effect of a pre-oxidation treatment

✍ Scribed by V. B. Trindade; U. Krupp; B. Gorr; D. Kaczorowski; G. Girardin; H.-J. Christ

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: German
• Weight: 398 KB
• Volume: 59
• Category: Article
• ISSN: 0947-5117
• DOI: 10.1002/maco.200804144

✦ Synopsis

Abstract

Nickel‐base superalloys are commonly used for high‐temperature applications in power‐generation industry, e.g., gas‐turbine blades or heat exchangers. They are designed to resist high creep loading and severe corrosion attack during operation. Nitridation is one of these corrosion processes, in particular when the alloys need to be exposed to a N~2~ atmosphere. Based on past assumptions, a dense oxide layer should be an efficient barrier against N~2~ ingress. But is this really the case? This work is focused on the nitridation behavior of commercial Ni‐base alloys and the influence of a pre‐oxidation treatment. To model the growth of the internal‐nitridation zone, the diffusion processes were solved using the numerical implicit finite‐difference method in combination with the subroutine ChemApp for thermodynamic calculations.