Cyclic-Softening Behavior of Ferritic-Martensitic Steels and Effects on Properties and Microstructures

I ALVAREZ; M.N. BATISTA; A.F. ARMAS

Encyclopedia of Iron, Steel, and Their Alloys

CRC Press - Taylor & Francis Group

Lugar: New York; Año: 2015; p. 1239 - 1248

The cyclic-softening behavior of reduced activation ferritic-martensitic steels EUROFER 97 and F82H for different thermo-mechanical conditions has been analyzed and compared with that of commercial steels AISI 410 and 420. These results show that the softening behavior can be described by a simple empirical relationship, which is dependent on the temperature and almost independent of the applied total-strain range. Alternatively, the softening behavior was analyzed using the flow stress components and the evolution of the dislocation structure. These results demonstrate that at high temperatures the back-stress controls the mechanism of cyclic softening, while at low temperatures the friction-stress is the dominant component.