Atomic resolution imaging of precipitate transformation from cubic TaN to tetragonal CrTaN

作者：Danielsen Hilmar K^*; Hald John; Somers Marcel A J

来源：Scripta Materialia, 2012, 66(5): 261-264.

DOI：10.1016/j.scriptamat.2011.11.005

• Phase transformations
• High-resolution electron microscopy (HREM)
• Heat-resistant steels
• Nitrides
• Crystal structure

In 9-12% Cr creep-resistant steels Cr(V,Nb,Ta)N Z-phase is known to replace metastable (V,Nb,Ta)N MN precipitates at high temperatures. The precipitation process of Z-phase does not follow the classical nucleation theory, where dissolving MN particles provide constituents for Z-phase nucleation in the matrix. Using atomic resolution transmission electron microscopy, the current work demonstrates that metastable cubic TaN precipitates in a complex steel gradually transform compositionally and crystallographically into stable tetragonal CrTaN precipitates under the influence of Cr indiffusion from the steel matrix.

• 出版日期2012-3