Introduction to the practical knowledge of the hot

2022-08-21
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Introduction to practical knowledge of nonferrous metals

§ 1 Classification of non-ferrous metals and expression methods of product brand

I. classification of non-ferrous metals

(1) non ferrous pure metals fell slightly into five categories of heavy metals, light metals, precious metals, semi metals and rare metals on the 7th day

(2) nonferrous alloys are divided into heavy nonferrous metal alloys, light nonferrous metal alloys, precious metal alloys, rare metal alloys, etc. according to the alloy system; According to the use of alloy, it can be divided into deformation (alloy for pressure processing), casting alloy, bearing alloy, printing alloy, cemented carbide, solder, master alloy, metal powder, etc

(3) non ferrous materials are classified by chemical composition: copper and copper alloy materials, aluminum and aluminum alloy materials, lead and lead alloy materials, nickel and nickel alloy materials, titanium and titanium alloy materials. When classified by shape, it can be divided into: plate, strip, strip, foil, tube, rod, wire, type and other varieties

II. Expression method of product brand

(1) naming principle the naming of non-ferrous metal and alloy product brand stipulates that the Chinese phonetic alphabet or international element symbols are used as the subject word code to indicate its category, such as l or Al for aluminum, t or Cu for copper. After the subject word, it is expressed by combining the numerical order of ingredients with the product category. That is, the code after the subject word can indicate the state, characteristics or main components of the product, such as LF is an aluminum (L) alloy that prevents (f) rust; LD is aluminum (L) alloy for forging (d); Ly is hard (y) aluminum (L) alloy, and the subject word of these three alloys is aluminum alloy (L). For another example, QSn is a kind of green (q) copper, and the main added element is tin (SN); QAL refers to green (q) copper, which contains aluminum (AL), the added element aluminum is 9%, and the other added elements are 4%. The subject word of these two alloys is bronze (q). Therefore, the product code is represented by the combination of Chinese phonetic alphabet, chemical element symbols and Arabic numerals of the subject words specified in the standard (GB)

the state, processing method and feature code of non-ferrous metal and alloy products are represented by the specified Chinese phonetic alphabet. For example, R (hot) for hot processing, C (quench) for quenching, B (no) without aluminum coating, X (fine) for fine particles, etc. But there are also a few exceptions, such as high-quality surface O (visualization indicates perfection), etc

§ 2 the tensile test of copper tensile machine is one of the most widely used methods to study the mechanical strength of materials. 1. Copper alloy

1. Pure copper

pure copper is a rose red metal, and its surface is purple after the formation of copper oxide film. Therefore, industrial pure copper is often called red copper or electrolytic copper. The density is g/cm3, and the melting point is 1083 ° C. Pure copper has good conductivity and is widely used in the manufacture of wires, cables, brushes, etc; With good thermal conductivity, it is often used to make magnetic instruments and meters that need to be protected from magnetic interference, such as compass, aviation instruments, etc; Excellent plasticity, easy to hot press and cold press processing, can be made into tubes, rods, wires, strips, strips, plates, foils and other copper materials. Pure copper products include smelting products and processed products

II. Copper alloy

(1) brass

brass is an alloy of copper and zinc. The simplest brass is copper zinc binary alloy, which is called simple brass or ordinary brass. Brass with different mechanical properties can be obtained by changing the content of zinc in brass. The higher the content of zinc in brass, the higher the strength and slightly lower the plasticity. The zinc content of brass used in industry is no more than 45%. No matter how high the zinc content is, brittleness will occur, which will deteriorate the properties of the alloy

in order to improve some properties of brass, brass added with other alloy elements on the basis of monobasic brass is called special brass. Commonly used alloy elements include silicon, aluminum, tin, lead, manganese, iron and nickel. Adding aluminum to brass can improve the yield strength and corrosion resistance of brass and slightly reduce the plasticity. Brass containing less than 4% aluminum has good processing, casting and other comprehensive properties. Adding 1% tin to brass can significantly improve the corrosion resistance of brass to seawater and marine atmosphere, so it is called "naval brass". Tin can also improve the machinability of brass. The main purpose of adding lead to brass is to improve machinability and wear resistance. Lead has little effect on the strength of brass. Manganese brass has good mechanical properties, thermal stability and corrosion resistance; Adding aluminum to manganese brass can also improve its performance and get castings with smooth surface. Brass can be divided into casting and pressure processing products. Chemical composition of commonly processed brass

(2) bronze

bronze is the earliest alloy used in history. It originally refers to copper tin alloy. Because its color is cyan gray, it is called bronze. In order to improve the technological and mechanical properties of the alloy, other alloy elements, such as lead, zinc, phosphorus, etc., are also added to most bronzes. As tin is a scarce element, many tin free Wuxi bronzes are also used in industry. They are not only cheap, but also have the required special properties. Wuxi bronze mainly includes aluminum bronze, beryllium bronze, manganese bronze, silicon bronze, etc. In addition, there are ternary or quaternary bronze with complex composition. Copper alloys other than brass and white copper (copper nickel alloy) are now called bronze

tin bronze has high mechanical properties, good corrosion resistance, friction reduction and good casting properties; It has small sensitivity to overheating and gas, good welding performance, no ferromagnetism, and small shrinkage coefficient. The corrosion resistance of tin bronze in atmosphere, seawater, fresh water and steam is higher than that of brass. Aluminum bronze has higher mechanical properties than tin bronze, wear resistance, corrosion resistance, cold resistance, heat resistance, non ferromagnetism, good fluidity, no segregation tendency, and dense castings can be obtained. Adding iron, nickel, manganese and other elements to aluminum bronze can further improve the properties of the alloy

bronze is also divided into pressure processing and casting products

(3) white copper

the copper base alloy with nickel as the main added element is silver white, which is called white copper. The copper nickel binary alloy is called ordinary white copper, and the copper nickel alloy with manganese, iron, zinc, aluminum and other elements is called complex white copper. The addition of nickel to pure copper can significantly improve the strength, corrosion resistance, resistance and thermoelectricity. Industrial white copper can be divided into structural white copper and electrical white copper according to different performance characteristics and uses, which meet various corrosion resistance and special electrical and thermal properties respectively

III. copper

it is made of pure copper or copper alloy in various shapes, including rods, wires, plates, strips, tubes, foils and so on. The processing of copper includes rolling, extrusion and drawing, and the plates and strips in copper include hot-rolled and cold-rolled; Both strip and foil are cold rolled; Pipes and bars are divided into extruded products and drawn products; All wires are drawn

§ 3 aluminum and aluminum alloy

aluminum is a light metal with low density (2.79/cm3) and good strength and plasticity. Aluminum alloy has good strength. The strength of superhard aluminum alloy can reach 600MPa, and the tensile strength of ordinary hard aluminum alloy can also reach MPa. Its specific stiffness is much higher than that of steel, so it is widely used in machine manufacturing. The conductivity of aluminum is second only to silver and copper, ranking third. It is used to make all kinds of wires. Aluminum has good thermal conductivity and can be used as various heat dissipation materials. Aluminum also has good corrosion resistance and good plasticity, which is suitable for all kinds of pressure processing

aluminum alloys can be divided into deformed aluminum alloys and cast aluminum alloys according to processing methods. Wrought aluminum alloys are also divided into non heat treatable strengthened aluminum alloys and heat treatable strengthened aluminum alloys. Non heat treatable reinforced type can not improve mechanical properties through heat treatment, but can only be strengthened through cold working deformation. It mainly includes high-purity aluminum, industrial high-purity aluminum, industrial pure aluminum and rust proof aluminum. Heat treatable strengthened aluminum alloy has the advantages of good linearity. It can be divided into hard aluminum, forged aluminum, superhard aluminum and special aluminum alloy by quenching, aging and other heat treatment methods to improve mechanical properties

aluminum alloy can obtain good mechanical properties, physical properties and corrosion resistance by heat treatment

cast aluminum alloys can be divided into aluminum silicon alloy, aluminum copper alloy, aluminum magnesium alloy and aluminum zinc alloy according to their chemical composition

I. pure aluminum products

pure aluminum is divided into smelting products and processed products after unloading the pressure swing oil return valve. The former is represented by the chemical composition Al, and the latter is represented by the Chinese Pinyin LG (aluminum, industrial)

II. Pressure processing aluminum alloy

aluminum alloy pressure processing products are divided into seven categories: rust prevention (LF), hard (ly), forging (LD), superhard (LC), coating (LB), special (LT) and brazing (LQ). The states of commonly used aluminum alloy materials are annealing (M simmering), hardening (y) and hot rolling (R)

III. aluminum materials

aluminum and aluminum alloys are collectively referred to as aluminum materials after being processed into certain shapes, including plates, strips, foils, tubes, rods, wires, types, etc

IV. cast aluminum alloy

cast aluminum alloy (ZL) is divided into four categories according to the main elements silicon, copper, magnesium and zinc other than aluminum in the composition, with code codes of 100, 200, 300 and 400 respectively

v. high strength aluminum alloy

high strength aluminum alloy refers to aluminum alloy with tensile strength greater than 480 MPa, mainly including medium hard aluminum alloy, super hard aluminum alloy and casting alloy of pressure processing aluminum alloy. (end)

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