The Chinese nation is the world's first iron smelting steel countries, our ancestors in three thousand years ago have some iron smelting, steelmaking, casting and heat treatment craft, 1700 years earlier than Europe, to the world civilization and made important contribution to human progress.
Steel for the modernization of industrial and agricultural production, transportation, national defense and people's lives, has become the most basic, the most important material. At present, although all sorts of new type of inorganic materials and organic synthetic materials have gained great development. But from the production cost, wide applicable performance, etc, they are far from to replace steel. So the steel production capacity is still one measure of a country's national strength important symbol. Iron and steel materials are so widely used, because iron ore deposits concentrated, large storage capacity, economical mining, smelting, steel semi-finished products cold and hot deformation ability. Manufactured with excellent mechanical properties (strength, plasticity and impact resistant ability) and machining properties (cutting, welding, cold deformation, etc.). But with silicate material, polymer composite materials, and compared some non-ferrous metals, its biggest drawback is: in the atmosphere, or under the condition of acid, alkali, salt and other medium, easy to weightlessness loss due to corrosion, and even destroyed.