Effect of ferrite embrittlement on the fatigue crack propagation in a 2205 duplex stainless steel

In the present paper fatigue crack propagation in a 2205 duplex stainless steel sheet (11 mm thickness) has been investigated. The tested samples have been studied in the quench annealed condition and in the 375 °C aged condition with two different holding time (100 and 1000 hours). Fatigue crack growth tests have been carried out in air at room temperature; three different stress ratio R have been assessed and the effect of anisotropy pointed out (LT and TL directions). The experimental data have been interpolated using the empirical relationship proposed by Paris. Microfractographic examinations and roughness measurements have been related to the crack growth rates.