Casting process optimization of stainless-steel pump impellers using finite element simulation

This study employed ProCAST numerical simulation to assess and enhance the casting design of a stainless-steel CF8M pump impeller by analyzing six gating and feeding configurations. The simulations were executed at a pouring temperature of 1650 °C, an initial mould temperature of 25 °C, and an estimated filling duration of 20 s. The examined configurations comprised a baseline horizontal design and modified designs featuring enhanced riser and gate arrangements, mould tilt angles ranging from 5° to 20°, and supplementary ventilation in the final design. The findings indicated that the original design resulted in detrimental temperature distribution and localized final solidification within the impeller body, especially around the hub and blade-hub connections, hence heightening the propensity for shrinkage porosity. The progressive alteration of the riser, sprue, gate configuration, mould angle, and ventilation system optimized the temperature gradient, augmented feeding efficiency, and relocated the final solidification zone towards the riser/feeder. Design 6, optimized with a 20° mould tilt and ventilators, had the most advantageous solidification characteristics and reduced anticipated shrinkage porosity within the functioning impeller body. The findings indicate that numerical simulation can significantly diminish dependence on conventional trial-and-error casting experiments by facilitating virtual evaluation of several design options before to production. This study presents a simulation-based approach for regulating solidification behavior, enhancing feeding efficiency, and reducing shrinkage porosity in the casting of stainless-steel pump impellers.