Optimized Design of Ductile Iron Valve Body Casting for Defect Minimization and Quality Enhancement

Abstract

Ensuring the production of superior castings devoid of foundry flaws while minimizing costs is a perpetual concern for foundries. Enhancing and refining manufacturing procedures are essential to attaining this objective. Computer simulation of foundry operations presents a contemporary substitute for costly and labour-intensive investigations in actual foundries, providing a reliable representation of casting. An in-depth investigation of the casting simulation outcomes enables the anticipation of several hazards that may lead to faults in castings, thereby diminishing their quality and, importantly, increasing production costs. This research analyses a computer simulation of ductile iron valve body casting at a Fine Cast Foundry. The valve body exhibited significant shrinkage defects, leading to a casting rejection rate of approximately 26%. A simulation of the casting process was conducted in accordance with actual shop-floor conditions. The initially designed gating and feeder system was found inadequate in mitigating the shrinkage issues. A revised configuration of the feeder system was proposed based on simulation insights, which, when implemented, led to a reduction in shrinkage-related defects from 26% to 1%. To ensure dimensional accuracy and realistic representation, 3D models were developed using NX 10.0 parametric software, and ProCAST was employed for casting simulation. Additionally, the Taguchi Design of Experiments (DOE) method was applied to optimize key green sand mould parameters. This statistical approach led to a significant reduction in sand mould-related defects, bringing the rejection rate down from 9% to 1.25%.