Sh ess analysis in a duplex steel - X-ray diffraction methodologies of macro and pseudo-macro stress analysis in a textured duplex stainless steel

Stress distribution in each phase of a highly textured duplex stainless ste el is analysed after plastic prestrain and also during an in situ elastic b ending solicitation. 2 X-ray diffraction methods were used to take into acc ount the crystallographic texture in the stress analysis. In the classical sin(2)psi method, anisotropic X-ray elastic constants were used. Although the stress uncertainty is satisfying, epsilon(phi psi) vers us sin(2)psi curves could not be fully described. This is due to low diffra cting intensity directions and the presence of local plastic strain incompa tibilities. The crystallite group method, which was the 2nd approach used, leads to the smallest obtained uncertainties. This method only gives the st ress corresponding to the major volume fraction of the considered phase. X-ray analysis indicates that the elastic behaviour can be considered the s ame for the 2 phases as observed during elastic bending. In the case of pla stic prestrain, the determined residual stresses indicate a lower elastic l imit of the ferritic phase, due to the higher nitrogen content of the auste nitic phase.