The shape of creep curves in nickel base superalloy C263

The creep behaviour of the nickel base superalloy C263 has been studied at constant load and temperature in the 480{36 MPa/700{950C eld. The shape of the creep curves has shown a very strong dependence on the applied stress. The experimental results have been rationalised supposing the mobile dislocation density increases during creep, from an initially low value at the beginning of the tests. With this hypothesis, the creep results have been modelled using two coupled dierential equations, that have been successful in describing the creep behaviour in the entire explored stress/temperature field.