In This State it is Called Cast-Iron or Pig-Iron

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It is very strong and hard, and yet it can bend without breaking

A common and useful metal

Iron is one of the commonest, and so cheapest, of all the metals; and this is a good thing, for it is the most useful. It is very hard and strong, and, with the proper machinery, easily worked. Its chief fault is that it quickly rusts when it is exposed to water or damp air, unless it is kept always polished or covered with paint.

Like other metals, iron is found in certain kinds of rocks, ad has to be got out of the earth by mining. The iron mixed with rock in its natural state, is called iron ore. The iron ore is first crushed, and then put into very hot furnaces, until the iron is melted out of the rock. It then flows out of the furnace as a white hot liquid, into moulds, where it is left to cool. When it is cold it is very hard, but brittle (that is, easily broken).

In this state it is called cast-iron or pig-iron.

To make this cast –iron strong and tough, it is again melted and stirred about; and after that, when it is red hot, it is rolled under heavy rollers ad beaten with great hammers. When the iron so treated is cold, it is not only very hard but also very tough, and cannot be broken easily. This wrought-iron is used wherever great strength is wanted, as for building ships, and making bridges, or for girders to support buildings.

It is used for all machinery, engines, parts of ships, and for knives, scissors, needles, swords and scientific instruments

Lastly, wrought-iron is made into steel, by a special process. Steel is the most perfect form of iron. It is very strong and hard, and yet it can bend without breaking and hard, and yet it can bed without braking. It takes a bright polish, and can be ground down to a very fine point or sharp edge. It is used for all machinery, engines, parts of ships, and for knives, scissors, needles, swords and scientific instruments.

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