The influence of chemical composition, microstructure, environment and anisotropy on the cyclic deformation and fatigue behaviour of the three main grades of engineering duplex stainless steels (DSSs) is discussed. It is shown that the description of the cyclic stress-strain response of a DSS in terms of three regimes, each associated to distinct controlling cyclic deformation mechanisms, applies to all three steels. In addition, the finding of shorter fatigue lives in seawater as compared to air is rationalised in terms of enhanced strain localisation and cracking phenomena. Finally, the marked anisotropy effects observed for rolled DSS under both monotonic tensile and high cycle fatigue conditions are analysed considering correlations between crystallographic texture, quantified in terms of the Taylor factors for the individual phases, and crack nucleation resistance.
展开▼
