Calculation of Time Temperature

Transformation Diagrams

H. K. D. H. Bhadeshia

Metal Science 16 (1982) 159-165

cml.postech.ac.kr

log{time}

Ms

ferrite

pearlite

bainite

martensite

Ae3

upper bainite

lowerbainite

Widmanstatten ferriteBs

Ws

x

Gibbs free energy

Carbon

G m

xm

G

Thermodynamics

Bainite-start temperature

Fe-0.33C-0.18Si-1.48Mn-0.26Ni-0.16Cr-0.27Mo wt%

Fe-0.27C-0.13Si-0.60Mn-0.19Ni-0.74Cr-0.55Mo wt%

Fe-0.38C-0.25Si-1.49Mn-0.24Ni-0.14Cr-0.41Mo wt%

Fe-0.38C-0.2Si-0.69Mn-1.58Ni-0.95Cr-0.26Mo wt%

Fe-0.32C-0.28Si-0.61Mn-3.22Ni-0.63Cr-0.22Mo-0.025V wt%

Fe-0.39C-0.23Si-0.62Mn-1.44Ni-1.11Cr-0.18Mo wt%

Fe-0.42C-0.31Si-0.67Mn-2.53Ni-0.72Cr-0.48Mo wt%

Fe-0.42C-0.31Si-0.67Mn-2.53Ni-0.72Cr-0.48Mo wt%

12

3 45

6

1. Fe-0.4C2. Fe-0.4C-2Si3. Fe-0.4C-1Ni4. Fe-0.4C-1Mn5. Fe-0.4C-1Mn-1Cr6. Fe-0.4C-2Mn

0 1 2 3 4 5 10 10 10 10 10 10

Time / s

800

700

600

500

400

300

200

Temperature / C

calculations

∆ti

ti

cooling curve

Time

Temperature

isothermal transformation curves