white iron

…either so-called gray iron or white iron, the colours shown by fracture. Gray iron contains more silicon and is less hard and more machinable than is white iron. Both are brittle, but a malleable cast iron produced by a prolonged heat treatment was developed in France in the 18th century,…

White cast irons are usually made by limiting the silicon content to a maximum of 1.3 percent, so that no graphite is present and all of the carbon exists as cementite (Fe₃C). The name white refers to the bright appearance of the fracture…

…of magnesium are added to white cast iron to transform graphite into spherical nodules, thereby significantly improving the strength and malleability of the iron. In addition, particulate magnesium blended with lime or other fillers is injected into liquid blast-furnace iron, where it improves mechanical properties of steel by combining with…

…cooled), it will form a “white” iron containing about 60 percent cementite, or iron carbide. This material is hard and wear-resistant, but it has no ductility at all. These cast irons are usually given a heat treatment to improve their mechanical properties.