Steel product is the indispensable important materials for national construction and the four modernizations, steel is various and widely used, according to the different shape of cross section, steel is generally classified into section, plank, pipe and metal products these four categories. Steel ingot or steel billet processed into various shapes, sizes and properties by the pressure, the formed material is called steel product. Most of the steel processing are steel through the pressure processing, make the processed steel (ingot or billet) plastic deformation. According to different steel processing temperature, steel product can be divided into cold and hot working two kinds. In order to facilitate steel production organizing, supply and improve the management work, steel product is also divided into heavy rail, light rail, large formed steel, medium formed steel, small formed steel, cold-formed steel, high quality steel, medium thickness plate, sheet steel, electrician silicon steel, strip steel, seamless steel tube welding, steel pipe, metal products, and other varieties.
According to the use of steel it can be divided into structural steel, steel plate, special steel and professional steel. Structural steel can be divided into two kinds, the construction and engineering using structural steel referred to construction steel, it is used for buildings, bridges, ships, boiler or other structure parts. Such as carbon structural steel and low alloy steel plate, rebar, etc. Machinery manufacturing structural steel is steel product used for steel parts of manufacturing machine structure. This kind of steel is basically all high quality steel or quality steel, mainly high quality carbon steel, alloy steel, easy cutting structural steel, spring steel, rolling bearing steel and so on. Tool steel is commonly used for manufacturing all kinds of tools, such as carbon steel, alloy steel, high speed steel, etc. According to use the tool steel can be divided into die steel, cutting tool steel and measuring tool steel. Special steel is the steel with special performance, such as stainless steel, heat-resistant not peeling acid steel, high resistance alloy, wear-resisting steel, magnets steel and so on. Professional steel is steel product for professional industrial department using, such as automotive steel, aviation steel, agricultural machinery steel, chemical machinery steel, boiler steel, welding rod and so on.
According to the quality of the steel it can be divided into ordinary steel, quality steel and high quality steel. In ordinary steel the impurity element is more, sulphur content is generally less than 0.05%, phosphorus content is less than 0.045%, such as carbon structural steel and low alloy steel and so on. Quality steel with less impurity element, sulfur and phosphorus content are generally less than 0.04%, such as high quality carbon steel, alloy steel, carbon steel and alloy steel, spring steel, bearing steel and so on. High quality steel contains few impurities element, sulphur content is generally less than 0.03%, and phosphorus content is less than 0.035%, such as structural alloy steel and so on. High quality steel usually adds symbols “A” or Chinese character “high” behind the steel grade for identification.