Page 32 - Curriculum Visions Dynamic Book

Mild steel
Mild steel – steel with a carbon content of about 0.25% – is one of the most widely used materials today. It is strong and readily available. Its main drawback is that it is a reactive metal and so corrodes readily. This means that all steel objects that are to be used where moisture is present must be protected in some way. Mild steel is
also naturally quite easily bent, which is an advantage for making shapes, but a problem when using steel in vehicle panels.
To overcome this problem the steel needs to be hardened.
 Steel is widely used in the construction industry,
for example in reinforced concrete buildings.
Here the strength of the steel helps to support the concrete. The steel mesh and rods used do not corrode, because once the concrete has set around them the steel is protected from the air and this prevents chemical corrosion.
 Despite being constantly exposed to moisture, all ships, and most containers, are still made from steel. This is because the cost of using other materials would be vastly greater. As with most uses of steel, manufacturers have to compromise between resistance to corrosion and cost. As a result, much research goes into protective coatings. Many steel structures are also protected electrochemically by cathodic protection.
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