Fatigue of steel in air at low cyclic loading frequency

This investigation was aimed at studying crack growth behaviour at extremely low loading frequencies of steels exhibiting low temperature creep. It was found that crack dormancy at low loading frequency is an intrinsic characteristic of the steels. Frequency can be an independent driving force, like the stress intensity factor range (ΔK) and the maximum stress intensity factor (Kmax), in low cyclic loading frequency regimes. A dormant state or threshold condition can be achieved by reducing loading frequency.