Philippe Quaegebeur

Cyclic plasticity of a duplex stainless steel under non-proportional loading

The low-cycle fatigue behavior of a duplex stainless steel, 60 % ferrite - 40 % austenite, is studied under tension-compression/torsion loading at room temperature. The influences of loading direction and loading path are analyzed. It is shown that the duplex stainless steel has an isotropic behavior under tension-torsion loading in monotonic as well as in cyclic conditions. The loading path induces an over-hardening on cyclic hardening of duplex stainless steel, but lower than the one on austenitic stainless steels. The effect of loading history is studied in terms of strain amplitude, mean strain and loading path. It is shown that only histories in strain amplitude and loading path have a small effect on the stabilized stress.

Cyclic behaviour of a duplex stainless steel under multiaxial loading: Experiments and modelling

Abstract The low-cycle fatigue behaviour of a duplex stainless steel, 60 % ferrite — 40 % austenite, is studied under tension-compression/torsion loading at room temperature. It is shown that the duplex stainless steel has an isotropic behaviour under cyclic proportional loading. The non-proportional loading paths induce an extra-hardening, but lower on duplex stainless steel than on austenitic stainless steels. Three models able to account for the extra-hardening are identified and tested on the experimental data base. Two of them give accurate predictions.

Load History in Fatigue: Effect of Strain Amplitude and Loading Path

The low-cycle fatigue behavior of a duplex stainless steel, 60 % a - 40 % y, is studied under tension-compression/torsion loading at room temperature and under strain control. It is shown that the duplex stainless steel has an isotropic behavior under cyclic proportional loading. The loading path induces an extra-hardening on cyclic hardening of duplex stainless steel but lower than that on austenitic stainless steels. The effect of loading history is studied in terms of strain amplitude, mean strain, and loading path. It is shown that only histories in strain amplitude and loading path have an effect on the stabilized stress.