High-temperature nitridation of Ni-Cr alloys

A. Kodentsov, J.H. Gülpen, C. Cserhati, J. Kivilahti, F.J.J. Loo, van

Research output: Contribution to journalArticleAcademicpeer-review

39 Citations (Scopus)
139 Downloads (Pure)

Abstract

The nitriding behavior of nickel-chromium alloys was investigated at 1398 K over the range 1 to 6000 bar of external nitrogen pressure. The morphology of the nitrided zone depends on the concentration of chromium in the initial alloy and the N2 pressure (fugacity) applied upon the system. The transition from CrN to Cr2N precipitation was observed within the reaction zone after nitriding at 100 to 6000 bar of N2 when the chromium content in the initial alloys was 28.0 at. pct or higher. It is shown that the ternary phase p (Cr10Ni7N3) is formed in this system at 1273 K. through a peritectoid reaction between Cr2N and nickel solid solution and becomes unstable above 1373 K. The thermodynamic evaluation of the Ni-Cr-N system was performed and phase equilibria calculated. Evidence for "up hill" diffusion of nitrogen near the reaction front during the internal nitridation of Ni-Cr alloys at 1398 K was found. It was attributed to the relative instability of chromium nitrides and strong Cr-N interaction in the matrix of the Ni-based solid solution within the nitrided zone.
Original languageEnglish
Pages (from-to)59-69
JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Volume27
Issue number1
DOIs
Publication statusPublished - 1996

Fingerprint

Dive into the research topics of 'High-temperature nitridation of Ni-Cr alloys'. Together they form a unique fingerprint.

Cite this