Steel is an indispensable and important material for national construction and the realization of the four modernizations. Wide application range and many varieties. According to the different cross-sectional shapes, steel products are generally divided into four categories: profiles, plates, pipes and metal products. In order to facilitate the organization of steel production, order supply and good management, it is also divided into heavy rail, light rail, large steel, medium steel, small steel, cold-formed steel, high-quality steel, wire rod, medium-thick steel and thin steel.
Production method of steel: most steel products are processed by pressure, so the steel products (billets, ingots, etc.) processed in this way. ) is plastically deformed. According to the different processing temperatures of steel, it can be divided into cold working and hot working.
The main processing methods of steel are:
Rolling: The billet passes through the gap (various shapes) between a pair of rotating rollers, and the cross section of the material is reduced and the length is increased due to the pressure of the rollers. This is the most commonly used production method for producing steel, mainly used for producing profiles, plates and pipes. Cold rolling and hot rolling.
Forged steel: a pressure processing method that uses the reciprocating impact of forging hammer or the pressure of press to change the blank into the shape and size we need. Generally divided into free forging and die forging, it is often used to produce materials with large cross-sectional dimensions such as large profiles and cogging.
Drawn steel: it is a processing method of drawing rolled metal blanks (molds, pipes, products, etc.). ) stretching through the die hole to reduce the cross section and increase the length, which is mainly used for cold working.
Extrusion: it is a processing method that steel is put into a closed extrusion cylinder, and one end is pressed, so that the steel is extruded from a specified die hole to obtain a finished product with a certain shape and size. Mostly used in the production of non-ferrous metal steel.
Before introducing the classification of steel, briefly introduce the basic concepts of ferrous metal, steel and nonferrous metal.
I ferrous metals, steel and non-ferrous metals
1. Ferrous metals refer to iron and its alloys. Such as steel, pig iron, ferroalloy, cast iron, etc. Both steel and pig iron are alloys based on iron and with carbon as the main additive element, which are collectively called iron-carbon alloys.
Pig iron refers to the products made of iron ore smelted by blast furnace, which is mainly used for steelmaking and casting. Cast pig iron is smelted in a smelting furnace to obtain cast iron (liquid), and the liquid cast iron is cast into cast steel, which is called cast iron.
Ferroalloy is an alloy composed of iron and carbon, silicon, manganese, chromium, titanium and other elements. Ferroalloy is one of the raw materials for steelmaking, which is used as deoxidizer and alloying element additive for steel.
2. Put pig iron for steelmaking into a steelmaking furnace and smelt it according to a certain process to obtain steel. Iron and steel products include direct casting of steel ingots, continuous casting billets and various steel castings. Generally speaking, steel refers to steel rolled into various shapes. Steel belongs to ferrous metal, but steel is not completely equal to ferrous metal.
3. Non-ferrous metals, also known as non-ferrous metals, refer to metals and alloys other than ferrous metals, such as copper, tin, lead, zinc, aluminum, brass, bronze, aluminum alloys and bearing alloys. In addition, chromium, nickel, manganese, molybdenum, cobalt, vanadium, tungsten and titanium are also used in industry. These metals are mainly used as alloy additives to improve the properties of metals, among which tungsten, titanium and molybdenum are mostly used to produce cemented carbide for cutting tools. These nonferrous metals are called industrial metals, in addition to precious metals: platinum, gold, silver and rare metals, including radioactive uranium and radium. Second, the classification of steel
Steel is an iron-carbon alloy with a carbon content between 0.04% and 2.3%. In order to ensure its toughness and plasticity, the carbon content generally does not exceed 1.7%. Besides iron and carbon, the main elements of steel are silicon, manganese, sulfur and phosphorus. There are many ways to classify steel, and the main methods are as follows:
1. Classification by quality
(1) Ordinary steel (P≤0.045%, S≤0.050%)
(2) High quality steel (both P and S are ≤0.035%)
(3) High quality steel (P≤0.035%, S≤0.030%)
2. Classification by chemical composition
(1) carbon steel: a. low carbon steel (c ≤ 0.25%); B medium carbon steel (c ≤ 0.25 ~ 0.60%); C. high carbon steel (C≤0.60%).
(2) Alloy steel: a. Low alloy steel (total content of alloy elements ≤ 5%); B medium alloy steel (the total content of alloying elements is 5-10%); C. high alloy steel (total content of alloying elements > 10%).
3. Steel products are classified according to forming methods: (1) forged steel; (2) cast steel; (3) hot rolled steel; (4) cold-drawn steel bars.
4. Steel is classified according to metallographic structure.
(1) Annealing: A. Submerged arc welding steel (ferrite+pearlite); B.*** steel precipitation (pearlite); C. steel precipitates through steel (pearlite+cementite); D ledeburite steel (pearlite+cementite).
(2) normalizing: a. pearlite steel; B. bainite steel; C. martensitic steel; Austenite steel.
(3) The steel has no phase change or partial phase change.
5. Classification by purpose
(1) steel for building and engineering: a. ordinary carbon structural steel; B. low alloy structural steel; C. steel bars.
(2) Structural steel: a. Steel for machinery manufacturing: (a) high-quality structural steel; (b) Surface hardened structural steel: including carburized steel, ammoniated steel and surface hardened steel; (c) free-cutting structural steel; 4. Steel for cold plastic forming: including cold stamping steel and cold heading steel;
B. spring steel; Bearing steel.
(3) Tool steel: a. Carbon tool steel; B. alloy tool steel; C. high-speed tool steel.
(4) Special performance steel: a. Stainless and acid-resistant steel; B. Heat-resistant steel: including oxidation-resistant steel, heat-resistant steel and valve steel; C. electrothermal alloy steel; D. wear-resistant steel; E. low temperature steel; Electrical steel.
(5) Professional steel-such as steel for bridges, ships, boilers, pressure vessels and agricultural machinery.
6. Comprehensive classification
(1) Ordinary steel A. Carbon structural steel: (a)Q 195 (b)Q2 15(A, B) (c)Q235(A, b, C) (d)Q255(A, b) (e) B. low alloy structural steel; C. ordinary structural steel for special purposes.
(2) High-quality steel (including advanced high-quality steel): a. Structural steel: (a) High-quality carbon structural steel (b) Alloy structural steel (c) Spring steel (d) Free-cutting steel (e) Bearing steel (f) Special-purpose high-quality structural steel; B tool steel: (a) carbon tool steel (b) alloy tool steel (c) high-speed tool steel; C. Special performance steel: (a) stainless acid-resistant steel (b) heat-resistant steel (c) electrothermal alloy steel (d) electrical steel (e) high manganese wear-resistant steel.
7. Classification of smelting methods
(1) According to furnace type: a. Open hearth steel: (a) acidic open hearth steel (b) alkaline open hearth steel; B converter steel: (a) acidic converter steel (b) alkaline converter steel [or (a) bottom-blown converter steel (b) side-blown converter steel (c) top-blown converter steel]; C. Electric furnace steel: (a) Electric furnace steel (b) Electroslag furnace steel (c) Induction furnace steel (d) Vacuum consumable furnace steel (e) Electron beam furnace steel.
(2) According to deoxidation degree and pouring temperature, steel is divided into: a. Boiling steel; B. semi-killed steel; C. killed steel; Special killed steel.
Steel refining components:
1. Mining (obtaining iron ore)
2. Mineral processing (crushing iron ore and magnetically separating it into iron concentrate)
3. Sintering (sintering iron concentrate into sinter with certain strength and particle size)
4. Smelting (conveying sinter to blast furnace, reducing sinter to molten iron by hot air and coke, and desulfurization).
5. Steelmaking (high-pressure oxygen in converter dephosphorizes molten iron and removes impurities to convert it into molten steel)
6.- Refining (further dephosphorization and impurity removal to improve purity)
7. Continuous casting (molten steel is cast into a certain shape in a hot state)
8.- Steel rolling (rolling continuous casting billets into various types of steel products required by users, such as plates, wires and pipes).
aluminium alloy
Al-based alloy. The main alloying elements are copper, silicon, magnesium, zinc and manganese, and the secondary alloying elements are nickel, iron, titanium, chromium and lithium.
Aluminum alloy has low density, but high specific strength, close to or higher than high-quality steel, good plasticity, can be processed into various profiles, has excellent electrical conductivity, thermal conductivity and corrosion resistance, and is widely used in industry, and its dosage is second only to steel.
Aluminum alloys are divided into two categories: cast aluminum alloys, which are used as cast; Deformed aluminum alloy can withstand pressure processing, and its mechanical properties are higher than as-cast. Can be processed into various forms and specifications of aluminum alloy materials. Mainly used for manufacturing aviation equipment, daily necessities, building doors and windows, etc.
Aluminum alloys can be divided into wrought aluminum alloys and cast aluminum alloys according to processing methods. Wrought aluminum alloys can be divided into non-heat treated aluminum alloys and heat treated aluminum alloys. Non-heat treatment strengthening type can not improve mechanical properties through heat treatment, but only through cold working deformation, mainly including high-purity aluminum, industrial high-purity aluminum, industrial pure aluminum and rust-proof aluminum. Heat-treatable strengthened aluminum alloys can improve their mechanical properties by means of heat treatment such as quenching and aging, which can be divided into hard aluminum, forged aluminum, superhard aluminum and special aluminum alloys.
Aluminum alloy can obtain good mechanical properties, physical properties and corrosion resistance through heat treatment.
Cast aluminum alloys can be divided into aluminum-silicon alloy, aluminum-copper alloy, aluminum-magnesium alloy and aluminum-zinc alloy according to chemical composition.
Pure aluminum can be divided into two categories: smelting products and pressure processing products. The former is represented by the chemical composition al, and the latter is represented by the Chinese phonetic alphabet LG (aluminum, industrial).
Aluminum alloy pressure processing products are divided into seven categories: rust prevention (LF), hardness (LY), forging (LD), superhard (LC), cladding (LB), special (LT) and brazing (LQ). The commonly used aluminum alloy materials are annealed (M-annealed), quenched (Y) and hot rolled (R).
Aluminum and aluminum alloys processed into certain shapes are collectively called aluminum materials, including plates, belts, foils, tubes, rods, wires and profiles.
Cast aluminum alloy (ZL) can be divided into four categories, namely, silicon, copper, magnesium and zinc, with code names 100, 200, 300 and 400 respectively.
High-strength aluminum alloy refers to aluminum alloy with tensile strength greater than 480 MPa, mainly including hard aluminum alloy, superhard aluminum alloy and casting alloy.
Use of alloy codes
1050 extrusion coils, various hoses and fireworks powder for food, chemical and brewing industries.
1060 requires high corrosion resistance and formability, but not high strength. Chemical equipment is its typical use.
1 100 is used to process parts that require good formability and high corrosion resistance but do not require high strength, such as chemical products, food industry devices and storage containers, thin plate processed parts, deep-drawing or spinning concave vessels, weldments, heat exchangers, printed boards, nameplates and reflective appliances.
1 145 packaging and heat insulation aluminum foil, heat exchanger
1 199 electrolytic capacitor foil, optical reflection deposition film
1350 wires, conductive stranded wires, buses and transformer belts
20 1 1 requires screws and machined products with good cutting performance.
20 14 is suitable for occasions requiring high strength and hardness (including high temperature). Aircraft heavy-duty, forgings, thick plates and extruded materials, wheels and structural components, first-stage fuel tanks for multi-stage rockets and spacecraft components, truck frames and suspension system components.
20 17 is the first 2XXX alloy used in industry. At present, its application scope is narrow, mainly including rivets, general mechanical parts, structural parts of structures and transport vehicles, propellers and accessories.
Aircraft structures, rivets, missile parts, truck hubs, propeller parts and other structural parts.
2036 Automobile Body Sheet Metal Parts
Structural parts and weapon structural parts of 2048 aerospace vehicle
2 124 aerospace structure
Piston of 22 18 aircraft engine and diesel engine, cylinder head of aircraft engine, impeller and compressor ring of jet engine.
22 19 space rocket welded oxidizer tank, supersonic aircraft skin, structural parts, working temperature -270~300 degrees celsius. Good weldability, high fracture toughness and high stress corrosion cracking resistance in T8 state.
23 19 alloy covered electrode and filler solder for welding and drawing.
26 18 die forgings and free forgings. Piston and aero-engine parts
2A0 1 Structural rivet with working temperature less than or equal to 100℃.
Axial compressor blade 2A02 of turbojet engine operating at 200~300℃.
2A06 aircraft structure with working temperature of 150~250℃ and rivets for aircraft structure with working temperature of 125~250℃.
The strength of 2A 10 is higher than that of 2A0 1 alloy, and it is used to manufacture aircraft structural rivets with working temperature less than or equal to 100 degrees Celsius.
2A 1 1 Medium strength structural members, propeller blades, building structural members of vehicles and airplanes. Medium strength bolts and rivets for aircraft
2A 12 Aircraft skins, partitions, ribs, beams and rivets. Structural parts of buildings and transport vehicles.
2A 14 Free forgings and die forgings with complex shapes
2A 16 Spacecraft components working at 250~300 degrees Celsius, welded containers and airtight cabins working at room temperature and high temperature.
2A 17 Aircraft parts with working temperature of 225~250℃.
2A50 Medium Strength Parts with Complicated Shapes
2A60 aero-engine compressor impeller, guide wheel, fan, impeller, etc.
2A70 aircraft skin, aircraft engine piston, guide wheel, wheel disc, etc.
2A80 aero-engine compressor blades, impellers, pistons, expansion rings and other parts with high working temperature.
2A90 aero-engine piston
3003 is used to process parts and components that require good formability, high corrosion resistance and good weldability, or work that requires both these properties and higher strength than 1XXX alloy, such as kitchen utensils, food and chemical products processing and storage devices, tanks and tanks for transporting liquid products, and various pressure vessels and pipelines processed with thin plates.
The tank body of 3004 all-aluminum tank requires parts with higher strength than 3003 alloy, chemical products production and storage equipment, sheet metal processing parts, building processing parts, building tools and various lamps and lanterns parts.
3 105 room partition, baffle, movable roof board, downpipe, plate molding parts, bottle caps, bottle stoppers, etc.
3A2 1 Aircraft fuel tank, oil gallery, rivet line, etc. Building materials and food and other industrial equipment.
Similar to 3003 alloy, 5005 has medium strength and good corrosion resistance. Used as conductor, cooker, dashboard, shell and architectural decoration. The anodic oxide film is brighter than the oxide film on 3003 alloy, which is in harmony with the color tone of 6063 alloy.
5050 sheet can be used as refrigerator and freezer lining, automobile air duct, oil pipe and agricultural irrigation pipe; It can also process thick plates, pipes, bars, special-shaped materials and wires.
5052 This alloy has good formability, corrosion resistance, candlelight, fatigue strength and moderate static strength, and can be used to manufacture aircraft fuel tanks and oil pipes, as well as sheet metal parts, instruments, street lamp brackets and rivets, hardware products, etc. of traffic vehicles and ships.
5056 magnesium alloy and cable sheath rivet, zipper, nail, etc. Aluminum clad wire is widely used in processing agricultural insect traps and other occasions requiring high corrosion resistance.
5083 is used in places that need high corrosion resistance, good weldability and medium strength, such as welding parts of ships, automobiles and aircraft plates; Pressure vessel, refrigeration device, TV tower, drilling equipment, transportation equipment, missile parts, armor, etc. Strict fire prevention measures are needed.
5086 is used in places that need high corrosion resistance, good weldability and moderate strength, such as ships, automobiles, airplanes, cryogenic equipment, TV towers, drilling rigs, transportation equipment, missile parts and decks.
5 154 Welded structures, storage tanks, pressure vessels, ship structures and offshore facilities, and transport tanks.
5 182 plate is used to process cans, automobile body panels, steering wheels, reinforcements, brackets and other parts.
5252 is used to manufacture high-strength decorative parts, such as automobile decorative parts. After anodic oxidation, it has a bright and transparent oxide film.
5254 containers for hydrogen peroxide and other chemical products
5356 Welding Al-Mg alloy covered electrode and welding wire with magnesium content greater than 3%
Welding structures, pressure vessels and pipelines of 5454 offshore facilities.
5456 steel plate, high-strength welded structure, storage tank, pressure vessel and ship material.
5457 Decorative parts of automobiles and other equipment that have been polished and anodized.
5652 Storage containers for hydrogen peroxide and other chemical products
5657 Decorative parts of automobiles and other equipment that have been polished and anodized, but in any case, it is necessary to ensure that the materials have a fine grain structure.
5A02 aircraft fuel tank and conduit, welding wire, rivet, ship structural parts.
The strength welded structure, cold stamping parts, welding container and welding wire in 5A03 can be used to replace 5A02 alloy.
5A05 welded structural parts, aircraft skin skeleton
5A06 welded structure, cold die forgings, welded container stress parts, aircraft skin bone parts.
5A 12 welded structural parts, bulletproof deck
6005 extruded profiles and pipes are used for structural components that require strength and height greater than 6063 alloy, such as ladders and TV antennas.
6009 automobile body panel
60 10 table: automobile body
606 1 requires various industrial structures to have certain strength, high weldability and corrosion resistance, such as pipes, rods, profiles and plates used for manufacturing trucks, tower buildings, ships, trams, furniture, mechanical parts and precision machining.
Building profiles, irrigation pipes and extruded materials for vehicles, benches, furniture and fences.
Extrusion materials for 6066 forgings and welded structures
6070 Heavy-duty welded structures, extrusion materials and pipes for automobile industry
6 10 1 gong * * High-strength bars, conductors, heat dissipation equipment for automobiles, etc.
6 15 1 is used for die forging crankshaft parts, machine parts and production rolling rings, which requires good malleability, high strength and good corrosion resistance.
620 1 high strength conductive rod and wire
6205 thick plate, pedal and high impact extrusion
6262 is a threaded high stress part, and its corrosion resistance is better than that of 20 1 1 and 20 17 alloys.
635 1 Extruded structural parts of vehicles, pipes for water and oil, etc.
6463 profiles of buildings and various electrical appliances, as well as automotive decorative parts with bright surfaces after anodic oxidation treatment.
6A02 Aircraft engine parts, forgings and die forgings with complex shapes.
7005 extrusion material is used to manufacture welded structures with high strength and fracture toughness, such as trusses, bars and containers of transport vehicles; Large heat exchangers, and parts that cannot be solid-solution treated after welding; It can also be used to make sports equipment, such as tennis rackets and softball bats.
7039 refrigerated containers, cryogenic instruments and storage boxes, fire-fighting pressure equipment, military equipment, armor plates and missile devices.
7049 is used for forging parts which have the same static strength as 7079-T6 alloy and require high stress corrosion cracking resistance, such as aircraft and missile parts-landing gear hydraulic cylinders and extrusions. The fatigue performance of the parts is almost the same as that of 7075-T6 alloy, but the toughness is slightly higher.
Plates, extrusions, free forgings and die forgings of 7050 aircraft structural parts. The requirements of alloy for manufacturing such parts are: high spalling corrosion resistance, stress corrosion cracking ability, fracture toughness and fatigue resistance.
Aluminum foil and ultra-thin strip of 7072 air conditioner; Cladding of 22 19, 3003, 3004, 5050, 5052, 5 154, 606 1, 7075, 7475, 7 178 alloy plates and tubes.
7075 is used to manufacture aircraft structures and futures. He requires high-stress structural parts and molds to have high strength and strong corrosion resistance.
7 175 is used for forging high-strength structures of aircraft. T736 material has good comprehensive properties, namely, high strength, spalling corrosion resistance, stress corrosion cracking resistance, fracture toughness and fatigue strength.
7 178 is used to manufacture high compression yield strength parts of aerospace vehicles.
Aluminum clad and non-aluminum clad plates, wing frames, longitudinal beams, etc. For the 7475 fuselage. Other parts with high strength and fracture toughness.
7A04 aircraft skin, screws and stress parts, such as girders, frames, ribs, landing gear, etc.
1. range
This standard specifies the status code of deformed aluminum alloy.
This standard is applicable to aluminum and aluminum processed products.
2. Basic principles
2. 1 The basic status code is expressed in English capital letters.
2.2 The subdivision status code is represented by the basic status code followed by one or more Arabic numerals.
2.3 basic status code
There are five basic states.
Description and application of code name
F the free machining state is applicable to products with special requirements for work hardening and heat treatment conditions during molding, and the mechanical properties of products in this state are not specified.
O annealing state is suitable for the processed products with the lowest strength after complete annealing.
H Work hardening state is suitable for products whose strength is improved by work hardening. After work hardening, the product may (or may not) undergo additional heat treatment to reduce its strength.
W Solution heat treatment state The treatment state is an unstable state, which is only applicable to alloys naturally aged at room temperature after solution heat treatment. This status code only indicates that the product is in the natural aging stage.
T Heat treatment state (different from F, O, H state) is suitable for stable products after heat treatment, with or without work hardening. T code must be followed by one or more Arabic numerals.