钢材分类（Classification of steels）.doc

钢材分类（Classification of steels） Classification of steel.Txt insane madman is not terrible, terrible is the spirit of normal madman! Classification of steel Classification of steel Steel is iron, carbon as the main component of the alloy, its carbon content is generally less than 2.11%. Steel is one of the most important metal materials in economic construction. Steel is divided into two major categories: carbon steel (carbon steel) and alloy steel by chemical composition. Carbon steel is an alloy obtained by smelting pig iron. Besides iron and carbon, it also contains a small amount of impurities such as manganese, silicon, sulfur and phosphorus. Carbon steel has a certain mechanical properties, but also has good technical performance, and low prices. Therefore, carbon steels have been widely used. But with the rapid development of modern industry and science and technology, the performance of carbon steel has not fully meet the needs, so people have developed a variety of alloy steel. Alloy steel is a multicomponent alloy obtained by adding certain elements (called alloy elements) on the basis of carbon steel. Compared with carbon steel, the properties of alloy steel have been improved greatly, so it has been widely used. In order to facilitate the production, storage, selection and research of steel products, steel must be classified. According to the use of steel, chemical composition, quality of different, can be divided into many types of steel: (1) classification by usage According to the use of steel, can be divided into structural steel, tool steel, special performance steel three major categories. 1. structural steel: (1) steel used for various machine parts. It includes carburizing steel, Quenched and tempered steel, spring steel and rolling bearing steel. (2) steel used as an engineering structure. It consists of carbon steel in armour, B, especially steel and ordinary low alloy steel. 2. tool steel: steel used to make all kinds of tools. According to the