The influence of aluminum nitride (AlN) precipitation on the hot ductility of medium manganese steels was investigated using hot tensile testing, as good hot ductility is essential for continuous casting. A reasonable hot ductility is reached up to 0.04% and at 1.6% aluminum. At 0.04% only few AlN precipitates due to slow kinetics. At 1.6%, coarse AlN precipitates at high temperatures, minimally affecting hot ductility. In contrast, 0.6% aluminum leads to significant ductility loss due to AlN precipitating at γ Fe grain boundaries. At 1% aluminum, higher nitrogen contents only slightly reduce hot ductility. Thus, hot ductility is mainly influenced by AlN precipitation from γ Fe . SEM-EDX analysis confirmed that fine AlN at γ Fe grain boundaries correlate with poor hot ductility.
David et al. (Tue,) studied this question.