hadi et al_crossland
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C d F ti f Hi h T t W ldCreep and Fatigue of High Temperature WeldsCreep and Fatigue of High Temperature WeldsCreep and Fatigue of High Temperature WeldsM H H f i b * P E O’D h b S B L bM.H. Hafezi a, b,*, P.E. O’Donoghue b, c, S.B. Leen a, bM.H. Hafezi , P.E. O Donoghue S.B. Leen
aMechanical Engineering College of Engineering and Informatics NUI Galway IrelandaMechanical Engineering, College of Engineering and Informatics, NUI Galway, IrelandbR I tit t f E i t l M i d E R h NUI G l I l dbRyan Institute for Environmental, Marine and Energy Research, NUI Galway, Ireland
cCivil Engineering, College of Engineering and Informatics, NUI Galway, Irelandg g, g g g , y,*[email protected]@nuigalway.ie
Next Generation Power Plants Cyclic Plasticity Analysis of Weld SpecimenNext Generation Power Plants Cyclic Plasticity Analysis of Weld Specimen400f
lflPl ti 300
(MP
a)
fp
:ruleflow Plastic 200
tres
s (
Qb
p )()(:hardeningIsotropic 100
St
Strain
prQbpr )()( :hardeningIsotropic 0
-0.6 -0.4 -0.2 0 0.2 0.4 0.6
Strain
pxcx p 2
:hardeningKinematic -100pxcx p 3
: hardeningKinematic
300
-200
prxJf )(3
:functionYield400
-300 yprxJf )(2
:function Yield-400
nyyxF 1 min)(
2expmod:modelonOptimisati
Figure 6 Experimental cyclic
i iyiyxF 2
min)(1
p :model onOptimisatiFigure 6 Experimental cyclic t t i d t f i
i
2 1
stress -strain data for service-Figure 2 Multi stub header unit cff
p N
: iprelationsh Manson-Coffinaged P91 (BM) at 600°C [4]. Figure 2. Multi-stub header unit ff2
pg ( ) [ ]
Figure 1 Moneypoint 915 MW power station; Challenges facing ne t generation400 Stress (MPa)
b)400 Stress (MPa)
)150Figure 1 Moneypoint 915 MW power station;
Kilrush IrelandChallenges facing next generation Stress (MPa)
b)( )
a)Kilrush, Ireland plants: 200200
100
Pa)
• More flexible operation, as 0Strain
0Strain (%)
2-k
(MP
)2
tanh(2
pcky More flexible operation, as renewable energy comes
0-0.005 -0.003 -0.001 0.001 0.003 0.005
0-0.6 -0.4 -0.2 0 0.2 0.4 0.650∆
σ/2
)2
(2
y
renewable energy comes onstream
-200-200Computer Code
Exp [4]
Modelonstream,Si ifi l hi h 400400
Computer Code
Exp [4]0
-0.05 0.05 0.15 0.25 0.35
• Significantly higher steam -400-4000 05 0 05 0 5 0 5 0 35
∆ɛp/2 (%)
Figure 7 Identification of Figure 8 a) Validation of plasticity model against testtemperature and pressure Figure 7 Identification of Figure 8 a) Validation of plasticity model against test d t f i d d P91 t 600°C [4] d b) C li
p pconditions e g for ultra- material parameters k , c, γ data for serviced-aged P91 at 600°C [4], and b) Cyclic conditions, e.g. for ultrasupercritical (USC) operation and softening stress-strain response, N = 1 and 60.supercritical (USC) operation, and C fi i ith bi
g p ,Figure 3 Photograph of a crack observed in a • Co-firing with biomass
Table 3 Material parameters [3]g g p
plant component and image of a Type IV crackTable 3. Material parameters [3].
plant component and image of a Type IV crackin a welded connection 6.5 mm 2.7 mm 3.25 mm Zone k c γ b Qin a welded connection. Zone k
(MPa)c
(MPa)γ b Q
(MPa)B
mm (MPa) (MPa) (MPa)
BM 210 166160 1289 0 56 96A k h ll i th d l t f hi h t t t i l d th b tB
25 mBMWM BM 210 166160 1289 0.56 -96A key challenge is the development of high temperature materials and the subsequent C
3.2HAZ HAZ 169 121076 649 0.31 -47prediction of service life and failure. Welded connections represent the weakest part of HAZ 169 121076 649 0.31 47
WM 185 205690 889 1 1 122
p p phigh temperature plant Thermal fatigue and creep failure commonly occurs at such A
WM 185 205690 889 1.1 -122high temperature plant. Thermal fatigue and creep failure commonly occurs at suchconnections leading to downtime and costly repair at a minimum or loss of life andconnections leading to downtime and costly repair, at a minimum, or loss of life and
i t l d t ienvironmental damage, at a maximum.
WMWM
Specific Aims & Objectives Radial Axial Hoop Equiv PlasticSpecific Aims & Objectives Radial stress
Axial stress
Hoop stress
Equiv. stress
Plastic Strain
p j stress stress stress stress Strain
1. Calibrate nonlinear creep-plasticity material models for creep-fatigue of weldsHAZ
2. Computational analyses of high temperature creep and cyclic plasticity of weldsHAZ
Co putat o a a a yses o g te pe atu e c eep a d cyc c p ast c ty o e ds3 Creep and fatigue failure prediction for welded high temperature components3. Creep and fatigue failure prediction for welded, high temperature components
BM
Figure 9 Elasto-plastic stress distributions for maximum applied strainCreep Analysis of Two-Material Specimen Figure 9 Elasto-plastic stress distributions for maximum applied strainCreep Analysis of Two Material Specimen 550
600 A i l St
5 2 5 r=0
600 Axial Stress (MPa)
5 mm 2.5 mm A ncr :equation Norton r 0
r=2.75400
mm
tR t
equa oo o
)1(B 500 r=3.25
400
WMBM 5 m r eq :stress Rupture )1(1 P
a)
200
2.5 r q
s (M
200
A rt:lifeCreep
450
tres
s
0∆ɛp
Mrt f :life Creep
al S
t0-0.004 -0.003 -0.002 -0.001 -1E-17 0.001 0.002 0.003 0.004Mf
400
Axi
a
200
T bl 1 A l t d t t f C M V t 640°C [1]
400-200
Table 1. Accelerated creep constants for CrMoV at 640°C [1]. BM HAZ WM400
BM
WM
Zone A (MPa/h) n M χ α 350
-400 WM
HAZZone A (MPa/h) n M χ α
B M t l (BM) 6 6 10 15 4 3 299 10 13 5 767 0 30 3 6 9 12
Axial Position (mm)600Base Metal (BM) 6.6 ×10-15 4 3.299 ×10-13 5.767 0.3 Axial Position (mm)
-600
Figure 10 Sample local stress-strain Figure 11 FE-predicted axial stress distributions.Weld Material WM) 6 6 ×10-14 4 4 141×10-12 4 8496 0 2639 Figure 10 Sample local stress strain responses in weld zones
Figure 11 FE predicted axial stress distributions. Weld Material WM) 6.6 ×10 4 4.141×10 4.8496 0.2639responses in weld zones.
Zone N (cycles) locationT bl 4Radial
Zone Nf (cycles) location Table 4. A i l H R tRadial
stressBM 2103 AFailure life Axial
tHoopt
Rupture stress
WM 1271 Bpredictionstress stress StressBM WM 1271 B
HAZ 624 C
prediction at 500°C
BM
HAZ 624 Cat 500 C.
ConclusionsConclusionsWM
1. Significant stress inhomogeneity was predicted in the two-material, uniaxial, creep test specimen, WM
g g y p , , p p ,with peak stresses along the bi-material interface.p g
2. Creep rupture was predicted in the base metal at the interface on the outer surface.Figure 4 Creep stress contour plots. 2. Creep rupture was predicted in the base metal at the interface on the outer surface. 3. A rate–independent, cyclic plasticity material model was calibrated against strain-controlled three-
g p p3. A rate independent, cyclic plasticity material model was calibrated against strain controlled three
material uniaxial test data based on high temperature tests at NUI Galway [3]2 22 2WM BM WM BM WM BMWM BM
material uniaxial test data, based on high temperature tests at NUI Galway [3].4 High temperature low-cycle fatigue cracking was predicted in the heat-affected zone consistentss ss
4. High temperature, low-cycle fatigue cracking was predicted in the heat-affected zone, consistent with the test data
1.5
tres
s 1.5
t S
tres1.5
tres
s 1.5
t S
tres
with the test data. 5 Future work will study creep fatigue damage interaction in welded power plant geometriesA
xial
St
ival
ent
Axi
al S
t
ival
ent
5. Future work will study creep-fatigue damage interaction in welded power plant geometries. 1
ized
A 1
d E
qu
i
1
ized
A 1
d E
qu
i
References orm
ali
mal
ized
orm
ali
mal
ized
References 0.5No
Outer Surface
0.5
No
rm Outer Surface0.5No
Centre-line0.5
No
rm Centre-line
1 Hyde T H and W Sun (1997) Int J Mech Sci 39(8): 885 8981. Hyde, T. H. and W. Sun (1997), Int J Mech Sci 39(8): 885-8982 Simo J C and T J R Hughes (1998) Computational Inelasticity Springer NY
00 1 2 3
Normalized Axial Position
00 1 2 3
Normalized Axial Position
00 1 2 3
Normalized Axial Position
00 1 2 3
Normalized Axial Position 2. Simo, J. C. and T. J. R. Hughes (1998), Computational Inelasticity, Springer, NY3 F h t l t b t d ASME P V l & Pi i C f P i 2013Figure 5 Steady state creep stress distributions in two material specimen
Normalized Axial Position Normalized Axial Position Normalized Axial Position Normalized Axial Position
3. Farragher et al., to be presented ASME Pressure Vessels & Piping Conference, Paris, 20134 H d CJ t l ASME PVP 2012 J l 15 19 2012 T t O t i C d
Figure 5 Steady-state creep stress distributions in two-material specimen.4. Hyde, CJ et al., ASME PVP-2012, July 15-19, 2012, Toronto, Ontario, Canada.Table 2. Failure time prediction (accelerated) p ( )
Zone t (hrs) LocationZone tf (hrs) Location The publication has resulted from research conducted with the financial support of Science FoundationBM 166 B The publication has resulted from research conducted with the financial support of Science Foundation Ireland under Grant Number SFI/10/IN 1/I3015
WM 2715 AIreland under Grant Number SFI/10/IN.1/I3015.
WM 2715 A