Malleable iron

Ductile cast iron

Description

White cast iron can be converted to malleable iron by decomposing the cementite to form graphite nodules. To form malleable iron, cast iron is annealed for 2-3 days at about 800C in an oxygen-free atmosphere, then the temperature is decreased slowly. The iron must be low in carbon and contain about 1.0 to 1.5% silicon. The silicon and heat convert any iron carbide to graphite which deposits in nodules. Slight additions of copper accelerates the annealing process. The term malleable iron has also been used to refer to wrought iron.

Synonyms and Related Terms

blackheart iron; whiteheart iron; nodular iron; ductile cast iron; wrought iron; fer malléable (Fr.); Schmiedbares Eisen (Deut.); Schmiedeeisen (Deut.); smeedbaar ijzer (Ned.); ferro fundido dúctil (Port.)

Authority

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996

• Website address 1 Comment: Olympus Microscopy Resource Center at http://www.olympusmicro.com/galleries/abramowitz/pages/ductilecastironsmall.html

• Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Cast_iron (Accessed Oct. 18, 2005)

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 489

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997