Abstract
The combined effects of temperature and frequency on the crack growth rate and the failure life were investigated using the compact tension specimens of 12Cr steel under creep and creep–fatigue interaction conditions. The creep–fatigue tests were performed by introducing the hold time of the maximum load. The stress intensity factor was used to correlate the crack growth rate. The general result is that at high frequency where the crack growth rate is proportional to the frequency, the cycle‐dependent fatigue process is dominant. As the frequency decreases, the crack growth rate decreases, however its growth does not still have a trend to approach that for creep within the experiment. The dependence of the crack growth rate on temperature was explained on the basis of the Arrhenius thermally activated process. The trend of the reciprocal of the failure life is similar to that of the crack growth rate.