Dislocation structures of duplex stainless steel in uniaxial and biaxial cyclic loading
Résumé
Austenitic-ferritic duplex stainless steel has been subjected to uniaxial and biaxial non-proportional cyclic loading with the same equivalent strain amplitude. The dislocation structures in specimens fatigued to fracture using both types of loadings were studied and compared. Uniaxial cyclic loading, both in austenitic and in ferritic grains, produces simple structures due to activation of predominantly one slip system. Non-proportional cyclic loading results in formation of cell and wall structures and thus in higher stress response of the material.