Abstract
The mechanism for the formation of Z-phase was investigated for samples of an 11CrMoVNbN steel aged at 593
°C for up to 50,000
h. X-ray diffraction indicates that Z-phase appears after 5000
h of aging, and its amount gradually increases up to 50,000
h aging at the expense of mainly Cr
2
N. Transmission electron microscopy shows that Z-phase nucleates in the V-enriched rim region of Cr
2
N precipitates, which forms due to the diffusion of V into the precipitates from the matrix. Nucleated Z-phase tends to grow relatively rapidly compared with the preexisting precipitates such as Nb(C,N) and M
23
C
6
. Z-phase seems to consume Cr
2
N by the nucleation and growth mechanism rather than the transformation mechanism. The main difference in the aged samples is that the Nb content of Z-phase is lower and that Z-phase does not replace Cr
2
N completely, compared to the results of the crept samples.
Graphical abstract
Image 1
Highlights
• Precipitation is studied for a martensitic steel aged at 593
°C for up to 50,000
h.
• Z-phase nucleates in the V-enriched rim region of Cr
2
N precipitates after 5000
h.
• Z-phase seems to consume Cr
2
N by the nucleation and growth mechanism.
Page:
40-40
Related
Batch download
Cited By
noting
Similar Literature
Submit Feedback
Please wait while the file you selected is being converted