Abstract In this paper, the N back-migration and restoration behavior of duplex stainless steels (DSSs) 2101 and 2205 (DSS2205) were studied. Experimental findings indicated that the Cr2N in the ferrite (α) persistently decreased for both steels during the cooling process from 1200 °C to 1000 °C, and the disappearance rate of Cr2N in DSS2205 was significantly faster than that of lean duplex stainless steel 2101 (LDX2101). On the one hand, due to the severe partitioning behavior of N atoms in α migrating back to austenite (γ), on the other hand, the enriched Mn in LDX2101 and the enriched Ni in DSS2205 exerted an impact on N migration. Also, the cumulative thermal deformation at 1200 °C contributed to the N migration back into γ with the assistance of high-density dislocations and thermal deformation energy. Furthermore, the softening mechanism of constituent phases was dominated by discontinuous dynamic recrystallization (DDRX) mechanism in both steels at a strain rate of 10 s−1, which was characterized by strain-induced boundaries migration from low-density dislocations to high ones.
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