Casting technique improvement for compacted graphite iron cylinder head based on prediction of shrinkage porosity

Numerical simulation of casting process and prediction of shrinkage porosities for a compacted graphite iron cylinder head were made. Results show that the mounting hole of injector is the last solidified position of molten metal. Shrinkage porosities mainly locate in the mounting hole of injector, the intake valve guide and the exhaust valve guide away from the sprue. Main reasons for the presence of shrinkage porosities are from the inadequate feeding of molten metal and too slow cooling of the mounting hole of injector. To prevent the occurrence of shrinkage porosities, the casting technique was improved according to the numerical results of casting process, i.e, increasing width of ingate and adding cold iron in the mounting hole of injector. Numerical simulation and actual casting show that the improved casting technique can effectively avoid the shrinkage porosities in cylinder head and improve casting quality of cylinder head.