Mechanism of the Bainite Transformation

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Presentation transcript:

Mechanism of the Bainite Transformation www.msm.cam.ac.uk/phase-trans

body-centred cubic cubic close-packed

DISPLACIVE RECONSTRUCTIVE

4

5

upper bainite 1 µm

lower bainite

Surface 1 Surface 2 50 µm Srinivasan & Wayman, 1968

Mechanical stabilisation is only possible with displacive transformations. Mechanical stabilisation never occurs with reconstructive transformations.

50 µm

Bhadeshia and Waugh, 1981

1 2 Fe-0.4C wt% Decarburisation time / s 500 400 300 Temperature / °C

Temperature Ae3' T' o x Carbon in austenite

s d c r 1

Growth is diffusionless. Strain energy must be accounted for.

Oka and Okamoto

Ohmori and Honeycombe