The predicted time to rupture for the undeformed INCONEL 718 superalloy, using the Sherby--Dorn correlation method, is 7.24e72 seconds.
Sherby--Dorn correlation method
The Sherby--Dorn correlation method is a semi-empirical method for predicting the time to rupture of materials under creep loading conditions. The method is based on the following equation:
t_r = exp((Q/(R*T)) - (n*log(sigma/A)))
where:
t_r is the time to rupture (seconds)
Q is the activation energy for creep (J/mol)
R is the gas constant (J/mol·K)
T is the temperature (K)
n is the stress exponent
sigma is the stress (MPa)
A is the stress parameter (MPa)
Material constants for INCONEL 718 superalloy
The following material constants are for INCONEL 718 superalloy:
Q = 520000 J/mol
R = 8.314 J/mol·K
n = 6.56
A = 4.62e8 MPa
Stress and temperature conditions
The following stress and temperature conditions are assumed:
sigma = 200 MPa
T = 873 K
Predicted time to rupture
The predicted time to rupture is calculated as follows:
t_r = exp((Q/(R*T)) - (n*log(sigma/A))) = 7.24e72 seconds
Therefore, the predicted time to rupture for the undeformed INCONEL 718 superalloy, using the Sherby--Dorn correlation method, is 7.24e72 seconds.