Comparison of strain/stress behaviour of a duplex stainless steel between mesoscopic and macroscopic scales by neutron measurements extended to the necking range

The mechanical behaviour of a duplex stainless steel is investigated through mesoscopic measurements by diffraction method. Especially, the lattice strains for large tensile macro-deformation, up to the fracture of the sample, were measured using Time-Of-Flight neutron diffraction method. A former study has been extended to the necking range, using special correction for macro-stress values. It has been found that during large plastic deformation the lattice stresses increase almost linearly with the macro-stress value. The experimental results enable also to verify the stress concentration tensor predicted by self-consistent model. For those large deformations, mechanical effects of ductile damage have been observed.

► A duplex stainless steel has been investigated using neutron diffraction. ► The study has been extended to the necking range that enables to see damage effects. ► A calibration process has been performed to correct the necking effect. ► Some plasticity parameters have been identified at several scales. ► A localisation relation has been compared with experimental data.