Kurdjumov-Sachs

1
Kurdjumov-Sachs
Nishiyama-Wasserman
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?
?
?
110
110
?
?
111
111
?
?
011
011
?
?
101
101
111
?
?
?
111
lt001gt
?
?
lt011gt
?
lt001gt
?
2
Banded Ferrite-Pearlite Microstructures
Normal
Nb microalloyed
3
Empirical Equations
?y a b (C) c (Mn) d (Ni)
....
1223
4
?y a b (C) c (Mn) ?y a b (C) c
(Mn) d(C x Mn)
5
?y a b (C) c (Mn) ?y a b (C) c
(Mn) d(C x Mn) ?y sin (C)
tanh (Mn)
6
Impact Energy
Test temperature / C
7
Accelerated cooling
700
UTS
600
Strength / MPa
500
TWO STAGE
yield
400
SINGLE STAGE
-40
toughness
FATT / C
-80
0 200 400 600
Forced cooling stop T / F
Amano et al., 1988
8
Accelerated cooling
AUSTENITE
THERMOMECHANICAL PROCESSING
Ar3
rapid cooling (ferrite)
RAPID COOLING
T
F
less rapid cooling (bainite)
AIR
COOLING
T
F
AIR COOLING
TIME
9
Commercial
roller quench
NKK on-line
accelerated
Nippon Nagoya
cooling
Works, DQ
Air cool
-1
Average cooling rate (800-500 C) / C s
10
ULCB Steel
Hulka et al., 1988
11
ULCB Steel
Hulka et al., 1988
12
Accelerated cooled Control rolled
Segregated zone
Segregated zone
0.4
0.3
0.2
0.1
0
0 50 100 0
50 100
DISTANCE ACROSS PLATE MID-THICKNESS / µm
Tamehiro et al.
13
250
o
900
C (finish rolling temperature)
200
o
790
C
150
0 5 10 15
20 25 30
DISTANCE THROUGH PLATE THICKNESS / mm
Tamuki et al.
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TENSILE STRENGTH
IMPACT ENERGY
YIELD STRENGTH
TRANSITION TEMPERATURE
CARBON / wt.
15
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ACCELERATED
700
COOLED
600
CONTROL
ROLLED
500
0.30 0.40
CARBON EQUIVALENT
C Mn/6 (CrMoV)/5 (NiCu)/15 wt.
Tamehiro et al.
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Ferrite - Pearlite
Acicular ferrite
Martensite
Yutori Ogawa
19
Pickering Irvine
20
Maximum fraction of bainite
xT0 - x
T0
V??
T
xT0 - x?
xT0 - x
?
xT0
x
Carbon
21
MARTENSITEApproximate habit plane indices

• Low-alloy stees, Fe-28Ni 1 1 1?
• Plate martensite in Fe-1.8C 2 9 5
• Fe-30Ni-0.3C 3 15 10
• Fe-8Cr-1C 2 5 2
• ? martensite in 18/8 stainless 1 1 1

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V?
dV? ( 1 - ) dV?
e
V
23
V????V?
dV? ( 1 - ) dV?
e
V
V????V?
dV? ( 1 - ) dV?
e
V
24
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Calculated creep rupture properties (Cole and
Bhadeshia)
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Calculated
Measured (Welds)
5
o
2.25Cr1Mo, 10
h, 510
C
300
Weld Metal
250
200
150
100
50
0
0.00
0.03
0.06
0.09
0.12
Carbon / wt
Cole and Bhadeshia, 1998
28
Calculated
Measured (Welds)
5
o
2.25Cr1Mo, 10
h, 565
C
200
Weld Metal
150
100
50
0
0.00
0.03
0.06
0.09
0.12
Carbon / wt
Cole and Bhadeshia, 1998
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Alloys proposed by Cambridge University,
manufactured at Nippon Steel
wt A B wt A B C 0.116 0.127 P 0.004 0.003
Si 0.014 0.012 S 0.0005 0.0005 Mn 0.47 0.48 Al
lt0.002 lt0.002 Ni 0.02 lt0.01 Ta lt0.001 lt0.001 Cr
8.96 8.66 Ti 0.003 0.004 Cu 0.004 0.003 B 0.
007 0.00064 Mo 0.71 0.30 N 0.0682 0.0705 V 0.22
0.21 O 0.0103 0.0089 Co 1.23 0.003 H 0.00008
lt0.00001 Nb 0.013 0.015 W 3.01
2.96
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Temperature / C
31
Steel A
Temperature / C
Steel B
Temperature / C
32
Temperature / C
33
Carbide reactions steel A
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
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Carbide reactions steel B
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
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Precipitation reactions, 10CrMoW
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
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Phase fractions, steel A
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
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Phase fractions, steel B
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
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Phase fractions, 10CrMoW
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
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Brun, Robson, Narayan, MacKay Bhadeshia, 1998
41
Brun, Robson, Narayan, MacKay Bhadeshia, 1998
42
2.25Cr1Mo 600 C
M3C
M2X
M23C6
Time / h
1000 h
43
3Cr1.5Mo 600 C
M3C
M23C6
100 h
Time / h
44
0.02500
NF616 600 C
M23C6
M
C
3
0.02000
0.01500
0.01000
Laves
M
X
0.00500
2
0.00000
1e-03
1e00
1e03
Time / h
1000 h
45
C Si Mn Nb wt Standard 0.11 0.21 1.24 M
icroalloyed 0.11 0.30 1.40 0.03
?ly ?uy ?uts Standard 285 320 480 Microa
lloyed 395 430 525
MPa
elongation CV / J, -20 C Standard 36 55-90
Microalloyed 32 100-190