On the cyclic behavior of fusion reactor ferritic-martensitic steels at intermediate temperature

M AVALOS; I ALVAREZ; A ARMAS

MATERIALPRUFUNG

Carl Hanser Verlag

Lugar: Berlin, Germany; Año: 2009 vol. 51 p. 376 - 381

0025-5300

The low cycle fatigue response of EUROFER 97 has been investigated at different total plastic strain ranges and temperatures between 20-450"C.Thecyclicbeh aviourhasbeen analyzedthrough the decomposition of the flow stress in back stress and friction stress,and different micro structuralmechanisms associatedwith cyclic softening were proposed to explain the differences observed inthose stresscomponents.At 20"C,thecyclicsoftening couldbe attributed to a progressively unpinning of dislocations from carbon atoms.At high er temperatures,the mechanicalsoftening effects agreewiththeevolutionfrom initiallyveryfinemartensiticlaths to a coarser equiaxialcells structure.Adecreaseofdislocation density in side the micrograins is observed for all the temperatures, to a higher degree for higher temperatures. he low cycle fatigue response of EUROFER 97 has been investigated at different total plastic strain ranges and temperatures between 20-450"C.Thecyclicbeh aviourhasbeen analyzedthrough the decomposition of the flow stress in back stress and friction stress,and different micro structuralmechanisms associatedwith cyclic softening were proposed to explain the differences observed inthose stresscomponents.At 20"C,thecyclicsoftening couldbe attributed to a progressively unpinning of dislocations from carbon atoms.At high er temperatures,the mechanicalsoftening effects agreewiththeevolutionfrom initiallyveryfinemartensiticlaths to a coarser equiaxialcells structure.Adecreaseofdislocation density in side the micrograins is observed for all the temperatures, to a higher degree for higher temperatures.