Molybdenum is a mild carbide stabilizing agent, retarding the pearlite transformation while the ferrite formation is effected just a little. As a consequence a ferritizing effect on the cast iron can be obtained by molybdenum concentrations of 0.1-0.3 %. This becomes apparent by high values of elongation and strength. In addition the elevated-temperature resistance is increased by molybdenum which decreases the danger of material deformation at temperature changes. Higher molybdenum concentration and long cooling times (thick section castings) achieve carbide formation and with it a loss of toughness. These molybdenum containing composite carbides are very stable and cannot be dissolved completely by a heat treatment.