<Tr> <Th> Ni - resist type 2 </Th> <Td> C 3.0, Si 2.0, Mn 1.0, Ni 20.0, Cr 2.5 </Td> <Td> Cast </Td> <Td>--</Td> <Td> 27 </Td> <Td> </Td> <Td> 140 </Td> <Td> Resistance to heat and corrosion </Td> </Tr> <P> Cast iron and wrought iron can be produced unintentionally when smelting copper using iron ore as a flux . </P> <P> The earliest cast - iron artifacts date to the 5th century BC, and were discovered by archaeologists in what is now modern Luhe County, Jiangsu in China . This is based on an analysis of the artifact's microstructures . Because cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required . It is strong under compression, but not under tension . Cast iron was invented in China in the 5th century BC and poured into moulds to make ploughshares and pots as well as weapons and pagodas . Although steel was more desirable, cast iron was cheaper and thus was more commonly used for implements in ancient China, while wrought iron or steel was used for weapons . </P> <P> In the west, where it did not become available until the 15th century, its earliest uses included cannon and shot . Henry VIII initiated the casting of cannon in England . Soon, English iron workers using blast furnaces developed the technique of producing cast - iron cannons, which, while heavier than the prevailing bronze cannons, were much cheaper and enabled England to arm her navy better . The technology of cast iron was transferred from China . Al - Qazvini in the 13th century and other travellers subsequently noted an iron industry in the Alburz Mountains to the south of the Caspian Sea . This is close to the silk route, so that the use of technology derived from China is conceivable . The ironmasters of the Weald continued producing cast irons until the 1760s, and armament was one of the main uses of irons after the Restoration . </P>

Compressive strength of cast iron as compared to tensile strength
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