ON THE CYCLIC BEHAVIOUR OF FUSION REACTOR FERRITIC-MARTENSITIC

M. AVALOS; I. ALVAREZ ARMAS; A.F. ARMAS; C. PETERSEN

Berlin, Germany

Conferencia; Sixth International Conference on Low Cycle Fatigue; 2008

Deutsch Verband fur Metalkunde DVM

The low cycle fatigue response of the ferritic-martensitic steel EUROFER 97 has been investigated at Dep = 0.2% and temperatures between 20ºC and 450ºC. The cyclic behaviour has been analyzed through the decomposition of the flow stress in internal and effective stress components and a change of the microstructural mechanism associated with cyclic softening was proposed to explain the differences observed in these stress components. At 20ºC the cyclic softening could be attributed to a progressively unpinning of dislocations from carbon atoms. At higher temperatures the mechanical softening effects agrees with the evolution from an initial very fine martensitic laths to a coarser equiaxial cells structure. has been analyzed through the decomposition of the flow stress in internal and effective stress components and a change of the microstructural mechanism associated with cyclic softening was proposed to explain the differences observed in these stress components. At 20ºC the cyclic softening could be attributed to a progressively unpinning of dislocations from carbon atoms. At higher temperatures the mechanical softening effects agrees with the evolution from an initial very fine martensitic laths to a coarser equiaxial cells structure. Dep = 0.2% and temperatures between 20ºC and 450ºC. The cyclic behaviour has been analyzed through the decomposition of the flow stress in internal and effective stress components and a change of the microstructural mechanism associated with cyclic softening was proposed to explain the differences observed in these stress components. At 20ºC the cyclic softening could be attributed to a progressively unpinning of dislocations from carbon atoms. At higher temperatures the mechanical softening effects agrees with the evolution from an initial very fine martensitic laths to a coarser equiaxial cells structure.