The Validation of Feeder Modeling for Ductile Iron Castings
A precise feeder design for a ductile iron casting is difficult, due to the complexities of its liquid–solid states transformation. During solidification, a negative pressure in castings is developed from the volumetric shrinkage as liquid iron solidified, while a positive pressure is added from the volumetric expansion as spheroidal graphite crystallized from the liquid iron. A unique crystalline structure of Austenite shell surrounds the spherical graphite and also increases the viscosity of feeding fluid flow. First principle model was applied for modeling the flow behavior of the residual liquid iron during solidification. The phenomenon of volumetric expansion as spheroidal graphite crystallized was also considered. The model was validated by real casting a cube-shaped cast. The predictions of the shrinkage area and porosities were confirmed by the hardness contours in the cross-sectional area of the castings. An optimized solidification modulus ratio of the feeder to this cube cast was suggested.
KeywordsDuctile cast iron Feeder design Hot spot Modeling validation Spheroidal graphite
The authors personally acknowledge the help of the colleagues in Shou Chen Industry Co., Ltd No. 168, Deli Rd., Taiping District, Taichung City 411, Taiwan (R.O.C.), for casting experiments.
- 1.Campbell J (2011) Complete casting handbook, metal casting process, metallurgy, techniques and design, first edition, pp 347–352 [1a], p 406 [1b], p 663 [1c], p 666 [1d]Google Scholar
- 3.Schmidt WA, Sullivan E, Taylor HF (1954) AFS Trans 9:70Google Scholar
- 5.Flow 3D Casts, Flow Science. https://www.flowsciences.com/2018.06
- 6.Richins DS, Wetmore WO (1952) Hydraulics applied to molten aluminum. Trans ASME, 725–732Google Scholar