Analysis of Class 2 Components in the Time-Dependent Regime
according to ASME Section VIII Division 2 Code Case 2843-2
Attention!
This calculation is only a simplified estimation, and does not replace a detailed design calculation.
Material
9Cr-1Mo-V
9Cr-1Mo-V +5%
9Cr-2W (Sr-based factorized)
9Cr-2W (N + Sr-based factorized)
9Cr-2W (S-based factorized)
Extrapolation of time-dependent properties
not allowed
up to 1 000 000 hrs
up to 3 000 000 hrs
up to 10 000 000 hrs
Design loads
Design temperature
°C
General primary membrane stress
P
m
MPa
Local primary membrane+bending stress
P
L
+
P
b
MPa
Operating loads
Maximum wall averaged temperature
°C
Minimum wall averaged temperature
°C
Maximum cycle low end temperature
°C
Maximum cycle hot end temperature
°C
Hold time temperature
T
HT
°C
General primary membrane stress
P
m
MPa
Local primary membrane stress
P
L
MPa
Local primary bending stress
P
b
MPa
Secondary stress range
Q
MPa
Primary+secondary stress range 2
S
alt
MPa
(optional)
First extreme principal stress
σ
1
MPa
Second extreme principal stress
σ
2
MPa
Third extreme principal stress
σ
3
MPa
Stress concentration factor
K
S
Duration of stress cycle
hrs
Number of stress cycles
n
c
Calculate
Calculated primary design stress efficiencies
Membrane stress
%
(Eq. 1)
Membrane+bending stress
%
(Eq. 2)
Calculated primary operating stress efficiencies
Membrane stress
%
(Eq. 3)
Membrane+bending stress
%
(Eq. 4, 5)
Calculated primary operating partial damages
Membrane stress
%
(Eq. 6)
Membrane+bending stress
%
(Eq. 7)
Test A-1 — if creep effects are negligible
Yield strength efficiency
%
(6.1 (a))
Criterion (a) — stress-to-rupture damage
% (max. 10 %)
(Eq. 8)
Criterion (b) — 1.25
S
y
creep strain
% (max. 0.2 %)
(Eq. 9)
Criterion (c) — combined stress efficiency
%
(Eq. 10)
Tests A-2 and A-3 — elastic strain analysis
(only one test required)
Test A-2 efficiency
%
(Eq. 17)
Test A-3 efficiency
%
(Eq. 18)
Tests B-1 and B-2 — simplified inelastic strain analysis
Test B-1 strain
% (max. 1 %)
(Fig. 8, 6.3.2 (a))
Test B-2 strain
% (max. 1 %)
(Fig. 9, 6.3.2 (a))
Creep-fatigue evaluation
Creep damage
%
(Eq. 32)
Fatigue damage
%
(Eq. 33)
Combined creep damage efficiency
%
(Eq. 34)
Combined fatigue damage efficiency
%
(Eq. 34)
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