Effects of Typical Inclusions on the As-Cast Microstructure and Recrystallization of Low-Density Steel

Herein, the effect of nonmetallic inclusions (NMIs) on the microstructure and dynamic recrystallization (DRX) of Fe-23Mn-6Al-0.7C low-density steel is studied. The specimens are separately added sulfur (S) and nitrogen (N) to change the characteristics of NMIs. As a result, the addition of S significantly increases the number of MnS inclusions and AlN-MnS complex inclusions in low-density steel. The addition of N results in a significant increase in the size of NMIs. In the results, NMIs act as the heterogeneous nucleation sites for austenite and refine the as-cast grains in low-density steel. In addition, the treated specimens are subjected to a thermal compression simulation experiment. During the thermal compression process, discontinuous DRX is considered to be the main recrystallization method in the experimental low-density steels. Meanwhile, the typical NMIs significantly accelerate the DRX within grains in low-density steel through the mechanism of particle-stimulated nucleation and continuous DRX. Herein, the effect of typical inclusions on the as-cast microstructure and dynamic recrystallization (DRX) for low-density steel is investigated. Typical nonmetallic inclusions can cause serious orientation local gradient and dislocation accumulation during thermal deformation and affect DRX progression mainly through the continuous DRX mechanism and particle-stimulated nucleation mechanism.image (c) 2024 WILEY-VCH GmbH