铸铁(cast iron)
铁的合金，含碳2～4%，还含有数量不等的矽、锰、硫、磷。铸铁是在高炉内还原铁矿石生产的，放出铁水浇注冷却成锭，称为生铁。铸铁与熟铁不同，不能锻造，只能铸造成型，性脆、抗拉强度低，但产品价廉。铸铁有较高的抗压强度，以致成为首要的结构金属。18～19世纪时，铸铁是比熟铁较为便宜的工程材料。20世纪建筑业以钢取代铸铁，但在工业中仍有许多用途，如汽车发动机缸体、农业机械和机器零件、管道、凹形器皿、火炉、熔炉等。按照断面颜色，铸铁有灰口或白口之分。灰口铁含矽较高，硬度较低，比白口铁加工性能好。白口铁和灰口铁均较脆。18世纪，在法国发展了白口铸铁经长时间加热处理生产可锻铸铁。1948年在美国和英国发明了在铸造状态下就有延伸性的铸铁。这类韧性铸铁，现已形成重要的金属体系，广泛用於齿轮、模具、汽车曲轴和许多其他机械零件。
English version：
cast iron
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 century, 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 colors 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. (see Seth Boyden). 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.