Comparison of the Low- and High-Cycle Fatigue Behaviour of Ferritic, Pearlitic, Isothermed and Austempered Ductile Irons

In this paper the low and high cycle fatigue behaviour of ten structural materials is analysed in terms of strain-life, stress-life and cyclic stress-strain curves. Push-pull, strain-controlled fatigue tests are performed and then the experimental data are processed according to the Standards in force as well as following a recent procedure proposed by the authors which ensures the compatibility conditions are satisfied. As a result, a three dimensional representation of the experimental data in a stress-strain-life diagram can be drawn. The stress-life, strain-life and cyclic stress-strain curves are the projection of a unique three-dimensional curve onto the co-ordinate planes.