Precipitation of AlN and MnS in Low Carbon Aluminium-Killed Steel

The precipitation kinetics of AlN and MnS in low carbon aluminium-killed steel was calculated. Transmission electron microscopy (TEM), energy disperse spectroscopy (EDS) and phase analyses have been used to investigate the morphology, compositions and particle size distribution of AlN and MnS precipitates in three positions of the coil. The particles of AlN and MnS precipitates in the ferrite region after coiling and distributes along and adjacent to the ferrite grain boundaries. The shapes of AlN are plate-like, the precipitates size is about 10 to 60 nm; the shapes of MnS are spherical, the precipitates size is about 200 to 600 nm. The precipitation behavior of AlN is sensitive to the isothermal temperature and holding time, the precipitation quantity and particle size distribution of AlN in different positions of coil are unequal.