Malleable Iron Casting

Abstract

The term Malleable Iron includes ferritic (or standard) malleable iron and pearlitic malleable iron. In commercial practice, the unqualified term “malleable iron” refers to the ferritic material. There are two types of ferritic malleable iron, namely, black heart and white heart. The black heart material has a matrix of ferrite with interspersed nodules of tempered carbon. The white heart type has a different form of tempered carbon and usually contains some combined carbon, because of its composition and method of manufacture. “Cupola Malleable Iron” is a ferritic grade produced by cupola melting for pipe fitting and similar thin section castings. Because of lower strength and ductility, cupola malleable usually is not specified for engineering castings. Pearlitic malleable iron is designed to have combined carbon in the matrix resulting in higher strength and hardness than is available in ferritic malleable iron.