Classification of steel?

The main raw materials of iron and steel production include iron ore, manganese ore, chromium ore, limestone, refractory clay, dolomite, siderite and other minerals of raw ore and finished ore, artificial block ore, iron alloy, coal washing, coke, gas and coal chemical products, refractory products, carbon products, etc.

Iron and steel products are the general name of metal products based on iron element (Fe). The daily form includes iron, crude steel, steel, iron alloy, etc. Because ferroalloy is mainly used as deoxidizer and alloy additive in steel making process in iron and steel industry, it is usually classified as the main raw material of iron and steel production rather than steel products in management and statistics. In addition, steel wire, steel wire, steel strand, iron wire, nails and other steel wire and its products belong to the reprocessing products of iron and steel products, do not belong to the metal base products. So statistically, iron and steel products only include pig iron, crude steel, steel products.

Iron is the "primary product" of iron and steel products. After further smelting, steel can be obtained. The two mainly differ according to the carbon content of iron based products. The product obtained directly from iron smelting is crude steel (the solid state is called billet or ingot). The crude steel becomes steel after being processed by casting, rolling, forging, extrusion and other methods.

Steel is the main form of final products provided by steel industry for social production and life. Due to the variety of steel products, complex specifications, in order to adapt to the needs of statistics, production, marketing, inventory and other aspects of management, the international usually steel is divided into long (also known as "profile"), flat (also known as "strip" or "steel plate"), steel pipe (also known as "pipe") and other four categories.

Railway steel

It is mainly used for the production and construction of steel for railway departments, mainly including light rail, heavy rail, industrial lift guide rail, crane rail, conductive rail, turnout rail and other rail, rail accessories; Rails weighing more than 30 kg per meter are heavy rail, and those weighing 30 kg or less are light rail.

Steel sheet pile

It refers to the steel used in bank protection engineering, excavation engineering and building foundation engineering, mainly including sheet pile, composite supporting pile and tubular supporting pile.

Large section steel

It refers to the height of not less than 80 mm I steel (I-beam), H steel, U steel (channel steel), Angle steel, Z steel, T steel, T steel, etc.

Medium and small section steel

It refers to I section steel (I-beam), H section steel, U section steel (channel steel), Angle steel, T section steel, and flat ball steel, window frame steel, etc., which are less than 80 mm in height.

Cold formed steel

It refers to finished steel with steel plate or strip bent into various section shapes under cold condition, mainly used in metal structure, metal furniture, transport machinery, agricultural machinery and pipeline.

Bar

It refers to the steel whose section shape is round, square, flat, hexagonal, octagonal and other simple sections, and is delivered in straight strips (except steel bars for concrete).

Rod and wire

It refers to the products delivered in disk shape after hot rolling, also known as wire, its cross section is usually round, oval, square, rectangular, hexagonal, octagonal, semicircular and so on. The output statistics also include the wire used by the enterprise for drawing steel wire, but the cut straight bar is included in the section steel.

Reinforcement

It refers to the steel used for reinforced concrete and the steel used for prestressed reinforced concrete. The cross-section is round, sometimes square with rounded corners, including circular steel bars, ribbed steel bars, torsion steel bars, etc.

Flat wood

Refers to the thickness and width, length ratio of flat steel, generally with "thickness × width × length" to indicate the product specifications; According to the production method can be divided into hot rolled steel plate, cold rolled steel plate.

Thick steel plate: refers to the thickness of more than 3 mm steel plate, the thickness of 50 mm and above for extra thick steel plate, mainly used in shipbuilding, boiler, bridge and high pressure vessel shell; The thickness of 3 ~ 50 mm is medium thick steel plate, mainly used in shipbuilding, boiler, bridge, armor and high pressure vessel shell.

Thin steel plate: refers to the thickness of no more than 3 mm steel plate, according to the rolling process is divided into hot rolled steel plate and cold rolled steel plate, mainly used in automobiles, electrical equipment, vehicles, agricultural machinery, containers, steel furniture, etc.

Steel strip (strip): is a width of a long strip of steel, mostly rolled into a roll shape, also known as strip steel. The width of 600 mm or more is a wide steel belt, and the width of less than 600 mm is a narrow steel belt.

Tin plate: commonly known as "tinplate", refers to the surface coated with a thin layer of metal tin steel plate, has good corrosion resistance, a certain strength and hardness, good formability, easy welding; Tin layer non-toxic tasteless, bright surface, can print pictures. Mainly used for food canning industry, chemical paint, oil, medicine and other packaging materials, can prevent iron dissolution into the packaging.

Galvanized plate: refers to the surface coated with a layer of zinc steel plate, steel plate galvanized is a widely used economic and effective anticorrosion method. According to the production process can be divided into hot galvanized sheet and electrogalvanized sheet, the former zinc layer thickness is thicker, used for corrosion resistance parts; The latter zinc layer thickness is thin and uniform, more used for paint or indoor supplies.

Organic coated steel plate: refers to galvanized plate, aluminum plating plate, galvanized aluminum alloy plate, cold rolled plate and so on as matrix material, surface coated with one or two layers of organic coatings (such as epoxy ester, polyester, acrylic, plastic sol, etc.) or coated with a layer of plastic film and obtained products, can be made of different colors or pressed out patterns, also known as color steel plate, Widely used in construction, transportation, containers, light industry, electrical appliances, furniture and meters and other industries.

Electrical steel plate: also known as "silicon steel sheet", "silicon steel sheet", refers to a very low carbon content of ferrosilicon soft magnetic alloy, generally silicon content of 0.5% ~ 4.5%; It is mainly used to make the iron cores of various transformers, motors and generators. According to the grain orientation, electrical steel plate is divided into oriented electrical steel plate and non-oriented electrical steel plate two categories, the former rolling magnetic property is significantly better than the transverse, mainly used for transformers; The latter rolling and transverse magnetic roughly the same, mainly used in electric motors.

Steel pipe

It refers to the steel with the two ends open and the hollow section, the length is larger than the surrounding, the specification is expressed by the external dimension (such as the outside diameter or side length) and the wall thickness, which can be used in the pipeline, thermal equipment, machinery industry, petroleum geological exploration, container, chemical industry and special purposes.

Seamless steel pipe: refers to the steel pipe made of a whole piece of metal without seams on the surface, according to the production method can be divided into hot rolled pipe, cold rolled pipe, cold drawn pipe, extrusion pipe, according to the section shape can be divided into circular and irregular two, according to the wall thickness can be divided into thick wall pipe and thin wall pipe. The maximum diameter of seamless pipe is 650 mm (expanded pipe), the minimum diameter is 0.3 mm (capillary), mainly used for petroleum geological exploration pipe, petrochemical cracking pipe, boiler pipe, bearing pipe and automobile, aviation high-precision structural steel pipe.

Welded steel pipe refers to the steel pipe with joint surface formed by bending steel strip or steel plate into round, square and other shapes. According to different welding methods, it can be divided into arc welding pipe, high frequency or low frequency resistance welding pipe, gas welding pipe, furnace welding pipe, bondi pipe, etc., according to the shape of the weld can be divided into straight seam welding pipe and spiral welding pipe. Electric welded steel pipe is used for oil drilling and machinery manufacturing, furnace welded pipe can be used for water, gas pipe, etc., big mouth straight seam welded pipe for high pressure oil and gas transmission, etc. Spiral welded pipe is used for oil and gas transmission, pipe pile, bridge pier, etc. Welded steel pipe has lower cost and higher production efficiency than seamless steel pipe.