The objective of this paper is to review the factors influencing the formation of degenerated graph- ite layers on the surfaces of ductile iron castings for chemical resins-acid molding and core-making systems and how to reduce this defect. In the resin mold technique the sulphur in the P-toluol sulphonic acid (PTSA), usually used as the hardener, has been identified as one factor causing graphite degeneration at the metal- mold interface. Less than 0.15% S in the mold (or even less than 0.07% S) can reduce the surface layer depth. Oxygen may also have an effect, especially for sulphur containing systems with turbulent flows in the mold, water-bearing no-bake binder systems, Mg-Silica reactions, or dross formation conditions. Despite the lower level of nitrogen in the iron melt after magnesium treatment (less than 90 ppm), nitrogen bearing res- ins have a profound effect on the frequency and severity of surface pinholes, but a limited influence on sur- face graphite degeneration. The objective of this paper is to review the factors influencing the formation of degenerated graph- ite layers on the surfaces of ductile iron castings for chemical resins-acid molding and core-making systems and how to reduce this defect. In the resin mold technique the Sulfur in the P-toluol sulphonic acid (PTSA), usually used as the hardener, has been identified as one factor causing graphite degeneration at the metal- mold interface. Less than 0.15% S in the mold (or even less than 0.07% S Despite the lower level formation, water-bearing no-bake binder systems, Mg-Silica reactions, or dross formation conditions. of nitrogen in the iron melt after magnesium treatment (less than 90 ppm), nitrogen bearing res-ins have a profound effect on the frequency and severity of surface pinholes, but a limited influence on sur face graphite degeneration.