Computer-aided engineering (CAE) simulation for the robust gating system design: Improved process for investment casting defects of 316L stainless steel valve housing

Abstract

Defects in investment casting will inevitably reduce the lifetime and degrade the casting quality and increase manufacturing costs, accordingly. In particular, shrinkage porosity was numerically conducted, and a retained melt modulus model was implemented to analyze highly probable regions. The proposed casting schemes of gating designs are compared by quality of casting (shrinkage porosity) and practical feasibility in terms of small hole drilling machinability. The purpose of this study was to determine the feasible plan with the lowest PES (percentage of elements with shrinkage porosity) while promoting the near net shape casting with minimum machining cost and increase material usage. Virtual thermo-dynamical sensors were adopted in the simulations to indicate the impacts of different gating system of pattern assembly on the cooling gradient and direction of solidification. The best-case scenario of investment casting conditions was chosen to fabricate valve housing in an investment casting foundry. Experimental results of X-ray image differentiated nearly none of the pernicious defects that typically occurred with proposed casting, authenticating the proposed scheme's efficacy accordingly.