2. Taylor & Thornton, ALSTOM Power, Rugby

4. 0.5 µm

5. b a

6. dV = ( ) dV
VV e V
dV = ( ) dV
VV e V

7. Robson, Jones & Bhadeshia, 1996

8. 2.25Cr1Mo
600 °C
M3C
M2X
M23C6
Time / h
1000 h

9. 3Cr1.5Mo
600 °C
M23C6
Time / h

10.
NF616
600 °C
M23C6 M C 3
Laves M X 2
1e-03
1e+00
1e+03
Time / h

11. Empirical Equations
y = a + b (%C) +c (%Mn)
+ d (%Ni) ....
1223

12. y = a + b (%C) +c (%Mn)
+ d(%C x %Mn)

13. y = a + b (%C) +c (%Mn)
+ d(%C x %Mn)
y = sin (%C) + tanh (%Mn)

16. Hyperbolic Tangents

17. The complexity of the model is given by the number of hidden units, i
The complexity of the model is given by the number of hidden units, i.e. the number of hyperbolic tangent functions included

20. y A B x

23. Brun, Robson, Narayan,
MacKay & Bhadeshia, 1998

24. Components of Creep Strength, 2.25Cr1Mo
iron + microstructure
550 °C
solid solution
600 °C
precipitates
Murugananth & Bhadeshia, 2001

25. elements in solution
Murugananth & Bhadeshia, 2001

26. Cole & Bhadeshia, 1999

27. GTA weld at 823 K (data from Nippon Steel)
600
500
400
300
200
100
20000
30000
40000
Life / hours
Cole & Bhadeshia, 1999

28. Cole & Bhadeshia, 1999

30. Linkweld Project, Siemens Power Generation
W5397 Weld Metal Rupture at 570 C
500
400
300
200
100 2 3 4 5 6
log(life / h)
Cole and Bhadeshia, 2000

31. Data from Manoir Industries
9Cr 1Mo type steel (Z1092, 600 °C)
300
200
Rupture stress / MPa
100 1 2 3 4 5
log (life / h)
Cole and Bhadeshia, 2000

33. Cool, 1996

34. Cool, 1996

35. 600 °C
As-welded
700 °C
650 °C
Cool, 1996

37. Coarsening diffusion r r flux concentration q a q aq c r aq c r1 2
flux q a q
concentration aq c r 1 aq c r 2
distance

38. Mean radius / m Time / s Number density Time / s10 -9 -8 -7 -6
1/3
Mean radius / m
1/2 10 9 8 7 6 5 4 3 2
Time / s 2 4 -3
Number density 18 m 10 9 8 7 6 5 4 3 2
Time / s
Fujita & Bhadeshia, 2000

39. Data from Abe, 1999 Fe-9Cr-W alloys M_23C_6 size / µm10 -2 -1 1
Data from Abe, 1999
Fe-9Cr-W alloys
0W 1W 2W 4W
M_23C_6 size / µm 10 4 3 2 1
Time at 600 °C / h

40. Coarsening accelerated by tungsten!-1
chromium alone 2
Effective diffusivity / m s
multicomponent 5 4 3 2 1
Tungsten / wt%
Bhadeshia, 2000

41. Mole fraction of phase 0.00 0.01 0.02 0.03 M_23 C_6 Laves phase 5 4 3
Tungsten / wt%
Bhadeshia, 2000

42. Multiphase coarsening
Laves
concentration
in ferrite q q
distance
Bhadeshia, 2000

43. The microscopic world Atom (10-8 cm) Nucleus (10-12 cm)
Nucleon (10-13 cm)
Quark (10-18 cm)
Gelletly, Phil. Trans.
Roy. Soc. Lond. A,
356 (1998) 1952.

44. Multicomponent coarsening
Venugopalan & Kirkaldy, 1978