CYCLIC MECHANICAL BEHAVIOR AND MICROSTRUCTURE OF A 12Cr-Mo-V MARTENSITIC STAINLESS STEEL

Abstract— The low cycle fatigue properties of a 12Cr-IMo-V martensitic stainless steel are investigated at room temperature and correlated with its microstructure. The mechanical test results show that the behavior of this steel depends on the applied strain level. The SEM and TEM studies bring out the role of ferrite islands embedded in a tempered martensite lath matrix. Plastic deformation is essentially accommodated by ferrite; this results in extrusion formation on the surface specimen and a cellular dislocation structure. When the strain level is high, it requires a greater contribution of the tempered martensite, ferrite alone being unable to accomplish all the plastic deformation.