Fatigue Crack Growth Behavior of High Manganese Austenitic TWIP Steels

Fatigue crack growth (FCG) behavior of three high manganese austenitic twin-induced plasticity (TWIP) steels with different stacking fault energy (SFE) was investigated, aiming at studying the correlation between the FCG resistance and the SFE of the steels. FCG tests were performed using three-point bending specimens at room temperature at stress ratio of 0.1 under the control of stress intensity factor range. Test results showed that the fatigue threshold values of these steels decrease with increasing the SFE. However, in the Paris regime, the crack growth rates of the steels do not appear to correlate directly with SFE. These results are discussed according to the degree of fatigue crack closure and the deformation mode of crack tip zone.