whiteheart malleable iron

White iron is a type of cast iron characterized by its hard, brittle nature due to all its carbon being in the form of cementite (Fe₃C). This gives it a bright fracture surface, hence the name "white iron." It's too hard to machine and is primarily used for its wear resistance or as a starting material for malleable cast irons.1

Whiteheart malleable iron is produced by heat-treating white iron in an oxidizing atmosphere. This process removes carbon from the surface, making the iron malleable. This contrasts with blackheart malleable iron, which is annealed in a neutral atmosphere to form graphite nodules, resulting in a less brittle material widely used in machinery.1