TiN inclusions distribution in the composite cross section of Titanium Micro-alloyed Steel slab: thermo-chemical modeling and automatic statistic analysis

A model for TiN (Titanium Nitride) inclusions precipitation was developed to investigate the precipitation and growth behavior of TiN inclusions during slab solidification for the entire cross-section of Titanium Micro-alloyed Steel (0.0077 wt%N, 0.12 wt%Ti) slabs. The model integrates the principles of heat transfer, thermodynamics, and kinetics to predict the size and concentration of TiN inclusions in slabs. The outcomes of the TiN inclusions precipitation model showed that the TiN inclusions size on the surface of the slab was 2.82 μm, the central TiN inclusions size was 10.07 μm, and the total TiN inclusions concentration was 0.073 wt%. The distribution of TiN inclusions in the slabs was ascertained by automated scanning electron microscopy/energy dispersive X-ray spectroscopy inclusion analysis (AZtec Steel system). The results showed a sharp decrease in the number density of TiN inclusions number and an increase in the average size from the surface to the center of the slab. The model validation revealed that the model might accurately simulate the maximum size of TiN inclusions in the slab. However, the presence of micron-sized TiN particles in the steel matrix resulted in an overestimation of the modelled TiN concentration as compared to the actual TiN concentration