Influence of Nb Stabilization on the Recovery and Recrystallization Kinetics of a Ferritic Stainless Steel: Consequences on Magnetic Losses

Softening kinetics of two 17% chromium (Cr) stainless steel grades that differ in niobium (Nb) content are compared. In the experiments, we observed that a low Nb stabilization makes recrystallization nucleation much faster and prevents incomplete recrystallization. A qualitative interpretation, based on interaction with precipitates, is proposed and explains the main features of the softening kinetics as well as the microstructures obtained. For the Nb stabilized grade, magnetic losses were measured in the deformed state and after recrystallization. Above a specific magnetizing frequency, the deformed state led to smaller losses than the recrystallized state. These results are believed to be attributed to a grain size effect.