Optimizing casting yield using computer simulation

The efforts of a foundry and feeding system supplier were combined to optimize yield for a casting, using computer simulation. A first-principles filling/solidification software package was combined with accurate metal, molding material and feeding system data, thus resulting in accurate predictions of filling and feeding performance. The casting Mas a two-on adapter, poured with low-carbon alloy steel. The conventional gating system consisted of a downsprue with two sepal-are ingates, one for each casting, and a single, 3x6-in. (7.6x15.2 cm) thick-walled exothermic feeding system. A second method utilizing a 3x6-in. direct pouring unit was employed to improve casting quality and yield. Computer simulation was used to evaluate the filling characteristics of both methods, and to evaluate the performance of the feeding systems. The filling characteristics of the direct pouring technology (sleeve with integral filter) were significantly less turbulent than the conventional gating system. Reduced turbulence combined with integral filtration means that application of direct pour technology would result in improvements in casting quality. Several castings were produced to compare the two methods, and the actual filling and solidification results agreed with the computer prediction. Casting appearance and quality were significantly enhanced and feed safety margin was improved. Implementation of dir-ect pour technology for this casting resulted in an 11% increase in casting yield.