Co-Precipitation Behavior of MnS and AlN in a Low-Carbon Steel

Abstract

In this work, the simultaneous precipitation of MnS and AlN particles in low-carbon steel and their effect on hot ductility is investigated. On basis of a thermal treatment, which involves an intermediate cooling and reheating step, the authors show that the two compounds can precipitate in a symbiotic manner under conditions, where precipitation of isolated AlN will otherwise be suppressed. This co-precipitation behavior is studied by transmission electron microscopy with energy dispersive X-ray spectroscopy, as well as accompanying thermokinetic simulations with the software package MatCalc. The calculated evolution of the phase fractions, mean radii as well as number densities of the two compounds shows good agreement with the experimental observations and, thereby, supports our interpretation of the MnS-AlN co-precipitation mechanism.