Author:

Keywords:

Science & Technology, Technology, Materials Science, Multidisciplinary, Metallurgy & Metallurgical Engineering, Materials Science, PHASE-FIELD SIMULATION, CRACKING SUSCEPTIBILITY, TRIP/TWIP STEELS, ALLOY-STEELS, NB, MICROSTRUCTURE, BEHAVIOR, SEGREGATION, CARBON, ENERGY, 0306 Physical Chemistry (incl. Structural), 0912 Materials Engineering, 0913 Mechanical Engineering, Materials, 4016 Materials engineering, 4017 Mechanical engineering

Abstract:

© 2018, The Minerals, Metals & Materials Society and ASM International. The influence of Nb addition on casting microstructures and high-temperature mechanical properties of Fe-Mn-C-Al-xNb TWIP steels was analyzed by phase-field modeling and experiments. Phase-field simulations showed that Mn, Nb, and C are enriched in inter-dendritic regions while Al is enriched in dendritic regions during solidification process of the investigated TWIP steels. Both phase-field simulations and microstructural characterization show that NbC precipitates are preferentially present near inter-dendritic boundaries. Nb addition slightly reduces hot ductility of the investigated steel at 1173 K (900 °C) while the Nb-added TWIP steels show better hot-ductility than the reference steel for deformation temperatures above 1373 K (1100 °C). NbC precipitates and inter-dendritic distances appear to be the most important variables that affect hot-ductility behavior of the investigated TWIP steels.