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Martensitic
Transformations
· The
Martensitic transformation occurs when the austenite
is cooled rapidly to below the MS- start temperature and results
from a displacive distortion of the crystal lattice caused by a supersaturation
of interstitial carbon. In the transformation the high temperature FCC
lattice transforms to a body-centered-tetragonal
(BCT) or a BCC lattice.
· The
photographs show Martensite formed in an Fe
- 1.8 wt% C alloy after quenching to (a) 24 C, (b) -60 C, and (c) -100
C . (dT/dt) is about 200 C/s |
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