Simulation prediction of CP-Ti slab ingot solidification structure based on the CAFE method

In the process of electron beam cold hearth melting (EBCHM) of commercially pure titanium (CP-Ti), the coarse grain structure of titanium ingots can lead to uneven stress distribution. This increases the tendency for surface cracks, significantly affecting critical properties such as strength and toughness. In this study, the grain growth of CP-Ti ingots during EBCHM was simulated using a combination of microscale cellular automata (CA) and macroscale finite elements (FE) within the ProCAST finite element software. To accurately predict the microstructure growth kinetics and casting conditions, the effect of bulk nucleation parameters on the solidification structure of CP-Ti ingots was investigated. The simulation results were verified by comparing them with metallographic sections of titanium ingots. In addition, the effects of ingot drawing speed and casting temperature on the solidification structure of CP-Ti ingots were examined. The experimental results show that the average grain size decreases and the number of nucleation sites increases as the drawing speed of the ingot and heat transfer film coefficient rises. Conversely, the average grain size increases and the number of nucleation sites decreases as the casting temperature rises. The results of the paper offering theoretical guidance for the stable mass production of high-quality CP-Ti ingots.