Alloy cast irons are considered to be those casting alloys based on the iron-carbon-silicon system that contain one or more alloying elements intentionally added to enhance one or more useful properties. Alloy cast irons can be classified as white cast irons, corrosion-resistant cast irons, and heat-resistant cast irons. This article discusses abrasion-resistant chilled and white irons, high-alloy corrosion-resistant irons, and medium-alloy and high-alloy heat-resistant gray and ductile irons. The article outlines in a list the approximate ranges of alloy content for various types of alloy cast irons. The article explains the effects of alloying elements and the effects of inoculants. In most cast irons, it is the interaction among alloying elements that has the greatest effect on properties. Inoculants other than appropriate graphitizing or nodularizing agents are used rarely, if ever, in high-alloy corrosion-resistant or heat-resistant irons.