cast iron


cast iron
an alloy of iron, carbon, and other elements, cast as a soft and strong, or as a hard and brittle, iron, depending on the mixture and methods of molding.
[1655-65; cast (ptp. of CAST1) + IRON]

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Alloy of iron that contains 2–4% carbon, along with silicon, manganese, and impurities.

It is made by reducing iron ore in a blast furnace (cast iron is chemically the same as blast-furnace iron) and casting the liquid iron into ingots called pigs. Pig iron is remelted, along with scrap and alloying elements, in cupola furnaces and recast into molds for a variety of products. In the 18th–19th centuries, cast iron was a cheaper engineering material than wrought iron (not requiring intensive refining and hammering). It is more brittle and lacks tensile strength. Its compressive (load-bearing) strength made it the first important structural metal. In the 20th century, steel replaced it as a construction material, but cast iron still has industrial applications in automobile engine blocks, agricultural and machine parts, pipes, hollowware, stoves, and furnaces. Most cast iron is 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 white iron. Both are brittle, but malleable cast iron (produced by prolonged heat-treating), first made in 18th-century France, was developed into an industrial product in the U.S. Cast iron that is ductile as cast was invented in 1948. The latter now constitutes a major family of metals, widely used for gears, dies, automobile crankshafts, and many other machine parts.

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      an alloy of iron that contains 2 to 4 percent carbon, along with varying amounts of silicon and manganese and traces of impurities such as sulfur and phosphorus. It is made by reducing iron ore in a blast furnace. The liquid iron is cast, or poured and hardened, into crude ingots called pigs, and the pigs are subsequently remelted along with scrap and alloying elements in cupola furnaces and recast into molds for producing a variety of products.

      The Chinese produced cast iron as early as the 6th century BC, and it was produced sporadically in Europe by the 14th century. It was introduced into England about 1500; the first ironworks in America were established on the James River, Virginia, in 1619. During the 18th and 19th centuries, cast iron was a cheaper engineering material than wrought iron because it did not require intensive refining and working with hammers, but it was more brittle and inferior in tensile strength. Nevertheless, its load-bearing strength made it the first important structural metal, and it was used in some of the earliest skyscrapers. In the 20th century, steel replaced cast iron in construction, but cast iron continues to have many industrial applications.

      Most cast iron is 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, and a cast iron that is ductile as cast was invented in the United States and Britain in 1948. Such ductile irons now constitute a major family of metals that are widely used for gears, dies, automobile crankshafts, and many other machine parts.

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Universalium. 2010.

Look at other dictionaries:

  • Cast iron — Iron I ron ([imac] [u^]rn), n. [OE. iren, AS. [=i]ren, [=i]sen, [=i]sern; akin to D. ijzer, OS. [=i]sarn, OHG. [=i]sarn, [=i]san, G. eisen, Icel. [=i]sarn, j[=a]rn, Sw. & Dan. jern, and perh. to E. ice; cf. Ir. iarann, W. haiarn, Armor. houarn.]… …   The Collaborative International Dictionary of English

  • cast iron — Iron I ron ([imac] [u^]rn), n. [OE. iren, AS. [=i]ren, [=i]sen, [=i]sern; akin to D. ijzer, OS. [=i]sarn, OHG. [=i]sarn, [=i]san, G. eisen, Icel. [=i]sarn, j[=a]rn, Sw. & Dan. jern, and perh. to E. ice; cf. Ir. iarann, W. haiarn, Armor. houarn.]… …   The Collaborative International Dictionary of English

  • cast-iron — adjective 1. ) made of cast iron 2. ) very definite, and certain to be effective: She claims to have a cast iron alibi. cast iron safety procedures 3. ) very strong, or able to deal with difficult conditions: a cast iron stomach cast iron nerves …   Usage of the words and phrases in modern English

  • cast-iron — adj 1.) a cast iron excuse/alibi/guarantee etc an excuse etc that is very certain and cannot fail 2.) made of cast iron ▪ a cast iron frying pan …   Dictionary of contemporary English

  • cast-iron — adj 1.) a cast iron excuse/alibi/guarantee etc an excuse etc that is very certain and cannot fail 2.) made of cast iron ▪ a cast iron frying pan …   Dictionary of contemporary English

  • Cast-iron — Cast i ron, a. Made of cast iron. Hence, Fig.: like cast iron; hardy; unyielding. [1913 Webster] …   The Collaborative International Dictionary of English

  • cast-iron — cast′ i′ron adj. 1) made of cast iron 2) not subject to change or exception: a cast iron rule[/ex] 3) hardy: a cast iron stomach[/ex] • Etymology: 1655–65 …   From formal English to slang

  • cast iron — ► NOUN 1) a hard alloy of iron and carbon which can be readily cast in a mould. 2) (before another noun ) firm and unchangeable: a cast iron guarantee …   English terms dictionary

  • Cast iron — Cast i ron Highly carbonized iron, the direct product of the blast furnace; used for making castings, and for conversion into wrought iron and steel. It can not be welded or forged, is brittle, and sometimes very hard. Besides carbon, it contains …   The Collaborative International Dictionary of English

  • cast iron — 1660s, from cast (pp. adj.) made by melting and being left to harden in a mold (1530s), from CAST (Cf. cast) (v.) in sense to throw something in a particular way (c.1300) …   Etymology dictionary

  • cast-iron — [kast′ī′ərn] adj. 1. made of cast iron 2. very hard, rigid, strong, healthy, etc …   English World dictionary


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