Abstract
A fatigue crack growth rate (FCGR) equation,
had been proposed which predicts the observed Rβratio effects correctly. Conceptually, this equation accounts for spectrum loading effects via the parameter βKβ. The work presented deals with the temperature effect on the fatigue parameters entering the above FCGRβequation. For materials which do not experience a microstructural or a fracture mode transition within the temperature range of interest, the effect of temperature on the fatigue parameters βCβ and βΞK^T^β can be interpolated or extrapolated from relatively few experimental data. Extrapolation of these fatigue parameters for Inconel Xβ750 measured between 300Β° K and 900Β° K allowed a very accurate prediction of the FCGR at 4Β° K.
At higher temperatures the end of fatigue controlled crack growth is clearly indicated by a rapid increase of the fatigue parameter βCβ. There, the fatigue parameter βCβ increases withing a temperature span of 100Β° K by a factor of 10^2^. This kind of information is of utmost importance for materials application at elevated temperatures as in nuclear systems.