A calculation model for evaluation of sub critical crack propagation hightemperature
creep in metallic plates is proposed. The model is based on the first low of
thermodynamics on energy balance and the balance of energy change velocity in a metallic
plate, containing a macro crack and subjected to long-term static loading tension under hightemperature
field effect, thus providing the process of stable creep in the process zone near
the crack tip. On the basis of above mentioned the equation with original and final conditions
are obtained that composed the mathematical model for determining the sub critical crack
growth period under high-temperature creep in metallic plates
