Investigation of TiN precipitation Behaviour using a TRIZ method combined with a cellular automaton model

TiN precipitation during solidification strongly affects the microstructural quality of Ti-N microalloyed steels, but its transition from initial formation to local enrichment, stable nucleation and aggregation growth is difficult to describe using a simple model. In this study, a TRIZ-guided cellular automaton (CA) framework was developed to characterise the staged evolution of TiN precipitation. TRIZ analysis was first used to identify the functional gaps in the precipitation process and convert them into CA model elements, including the TiN_b stable-nucleation state, the nucleation threshold n and the aggregation radius R. A two-dimensional 400 × 400 CA lattice was then used to simulate TiN formation, stable nucleation and aggregation behaviour. The results show that increasing n markedly reduces the number of TiN_b nucleation sites, and n = 3 provides a balanced description under the present model conditions. Among the tested aggregation radii, R = 15 gives the closest agreement with the observed coexistence of clustered and dispersed TiN. TEM/EDS characterisation confirms Ti-containing precipitates mainly associated with TiN. The calibrated values n = 3 and R = 15 are model-specific parameters rather than universal constants.