Metal materials are usually divided into ferrous metals, nonferrous metals and special metal materials. (1) ferrous metals, also known as steel materials, include industrial pure iron containing more than 90% iron, cast iron containing 2% ~ 4% carbon, carbon steel containing less than 2% carbon, and various structural steels, stainless steels, heat-resistant steels, high-temperature alloy stainless steels and precision alloys. The generalized ferrous metals also include chromium, manganese and their alloys. (2) Non-ferrous metals refer to all metals except iron, chromium and manganese and their alloys, which are usually divided into light metals, heavy metals, precious metals, semi-metals, rare metals and rare earth metals. Generally, the strength and hardness of non-ferrous alloys are higher than those of pure metals, with large resistance and small temperature coefficient of resistance. ③ Special metal materials include structural metal materials and functional metal materials with different uses. Among them, there are not only amorphous metal materials obtained by rapid condensation, but also quasicrystal, microcrystalline and nanocrystalline metal materials. There are also special functional alloys such as stealth, hydrogen resistance, superconductivity, shape memory, wear resistance, vibration reduction and damping, and metal matrix composites.
Question 2: What are the metallic materials and what are they? Metal materials are generally divided into ferrous metals and nonferrous metals.
1 ferrous metal
A substance with metallic properties, which is mainly composed of iron, manganese and chromium, is called a ferrous metal. Such as carbon steel, alloy steel and cast iron.
nonferrous metal
Metallic materials other than ferrous metals are called nonferrous metals, such as copper, aluminum, magnesium and their alloys.
Question 3: What metallic materials are included in metallic materials? They refer to metallic elements or materials with metallic characteristics mainly composed of metallic elements. Include pure metals, alloy, intermetallic compounds of metallic materials and special metallic materials. (Note: Metal oxides (such as alumina) are not metal materials)
See Baidu Encyclopedia: baike.baidu/subview/40361715379195 for details.
Question 4: What are the materials of steel? What are the classifications of steel?
Wire: ordinary high-speed wire reinforcement.
Materials: I-beam, channel steel, angle steel, square steel, heavy rail, high carbon steel, H-beam, round steel, equilateral angle steel, flat steel, light rail gear steel, hexagonal heat-resistant steel bar, combined round steel, square steel, carbon steel bearing steel, carbon steel, stainless steel bearing steel and rectangular tube spring steel.
Plate: medium container plate, carbon plate, boiler plate, low alloy plate, rhombic plate, cold plate, hot plate, hot coil plate, galvanized plate, galvanized plate, galvanized plate, manganese plate, stainless steel, silicon steel plate, color coated plate, colored steel corrugated iron galvanized coil, hot rolled strip steel.
Tubing: welded pipe, stainless steel pipe, hot-dip galvanized pipe, cold-dip galvanized pipe, seamless pipe, spiral pipe, hot-rolled and seamless.
I ferrous metals, steel and non-ferrous metals
Before introducing the classification of steel, briefly introduce the basic concepts of ferrous metal, steel and nonferrous metal.
1, ferrous metals refer to iron and ferroalloys. Such as steel, raw iron alloy, 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. Pig iron is melted in a melting furnace to obtain cast iron (liquid), and the liquid cast iron is cast into a casting. This kind of cast iron is called cast iron.
Ferroalloy is an alloy composed of iron, 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 kinds of steel. 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, classified 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 alloying elements ≤ 5%) B. Medium alloy steel (total content of alloying elements > 5 ~ 10%) C. High alloy steel (total content of alloying elements >10%).
3. Classification according to forming mode: (1) forged steel; (2) cast steel; (3) hot rolled steel; (4) cold-drawn steel bars.
4, according to the metallographic organization classification
(1) A. Sub-* * steel (ferrite+pearlite) b.*** steel (pearlite) C. Over-* * steel (pearlite+cementite) D. ledeburite steel (pearlite+cementite).
(2) normalizing: a. pearlite steel; B. bainite steel; C. martensitic steel; Austenite steel.
(3) 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) quenched and tempered structural steel; (b) Case-hardened structural steel: including carburized steel, ammonia steel and case-hardened steel; (c) free-cutting structural steel; (d) Steel for cold plastic forming: including steel for cold stamping and steel for cold heading. Spring steel bearing steel
(3) tool steel: a >>
Question 5: What are the metal majors? Metal majors are:
Metal material engineering: The major of metal material engineering is a basic subject in the field of material science and engineering. According to the latest professional catalogue of the Ministry of Education, metal materials cover metallurgy, nonferrous metals, composite materials, powder metallurgy, material heat treatment, material corrosion and protection, and surfaces.
Metallurgical engineering: Metallurgical engineering is an engineering technology field that studies the extraction of metals and their compounds from ores and other resources and makes them into materials with good processing and using properties.
Welding technology and engineering: The specialty of welding technology and engineering is an interdisciplinary subject integrating material science, engineering mechanics and automatic control technology. Teaching is based on the comprehensive application of various knowledge and the basic training of engineers.
Metal mineral processing engineering: it is an applied technical discipline to study mineral separation. Its purpose is to separate useful minerals from gangue (useless) minerals. For example, iron, copper, lead and zinc contain isochron minerals, and the low-grade raw ore is enriched into artificial rich ore through gravity separation, magnetic separation and flotation, so as to prepare for the next smelting work (smelting process belongs to metallurgical engineering specialty).
Mechanical engineering is an engineering discipline that uses physical laws to analyze, design, manufacture and maintain mechanical systems. Mechanical engineering is an applied discipline that studies and solves all theoretical and practical problems in the development, design, manufacture, installation, operation and maintenance of various machinery based on related natural and technical sciences and combined with technical experience in production practice. Mechanical engineering is a first-class discipline and a field of engineering graduate education.
Question 6: What are the common metal materials in life? 1, cast iron-fluidity.
As an inconspicuous part of our daily living environment, sewer manhole covers are rarely noticed. The reason why cast iron has such a large number of extensive uses is mainly because it has excellent fluidity and is easy to cast into various complex shapes. Cast iron is actually the name of a mixture of many elements, including carbon, silicon and iron. The higher the carbon content, the better the flow characteristics during pouring. Carbon appears here in the form of graphite and iron carbide.
Material characteristics: good fluidity, low cost, good wear resistance, low curing shrinkage, high brittleness, high compressive strength and good machinability.
Typical uses: Cast iron has been used for hundreds of years, involving buildings, bridges, engineering parts, homes, kitchen utensils and other fields.
2. Stainless steel-a revolution without rust
Stainless steel is an alloy composed of chromium, nickel and other metal elements in steel. Its rust resistance comes from the composition of chromium in the alloy, and chromium forms a solid and self-repairing chromium oxide film on the surface of the alloy, which is invisible to our naked eyes. The ratio of stainless steel to nickel we usually mention is 18: 10.
Material characteristics: health care, anti-corrosion, fine surface treatment, high hardness, and it is difficult to form and cold work by various processing techniques.
Typical uses: Austenitic stainless steel is mainly used for household goods, industrial pipelines and building structures; Martensite stainless steel is mainly used for manufacturing tools and turbine blades; Ferritic stainless steel has corrosion resistance and is mainly used for durable washing machines and boiler parts. Composite stainless steel has stronger corrosion resistance, so it is often used in corrosive environment.
3. Zinc-730 pounds in a lifetime
Silver-white and slightly blue-gray zinc is the third most widely used nonferrous metal after aluminum and copper. According to a statistic by the US Bureau of Minerals, an average person will consume 33 1 kg of zinc in his life. Zinc is an ideal casting material because of its low melting point. Zinc castings are very common in our daily life: door handles, faucets, electronic components and other subsurface materials. Zinc has a very high corrosion resistance, which makes it have another basic function, that is, as a surface coating material for steel. Metal processing wechat, with good content, deserves attention. In addition to these functions, zinc is also an alloy material with copper to synthesize brass. Its corrosion resistance is not only applied to steel surface coating ―― it also helps to strengthen our human immune system.
Material characteristics: health care, corrosion resistance, excellent castability, excellent corrosion resistance, high strength, high hardness, cheap raw materials, low melting point, creep resistance, easy alloy formation with other metals, health care, fragile at room temperature, and malleable at about 100 degrees Celsius.
Typical use: components of electronic products. Zinc is one of the alloy materials that form bronze. Zinc also has the characteristics of cleanliness, hygiene and corrosion resistance. In addition, zinc is also used in roofing materials, photo discs, cell phone antennas and shutter devices in cameras.
4. Current material-aluminum (al)
Compared with 9000-year-old gold, aluminum, a white metal with a slight blue light, can only be regarded as a treasure among metal materials. Aluminum came out and was named1at the beginning of the 8th century. Different from other metal elements, aluminum does not exist in the form of direct metal elements in nature, but is extracted from bauxite (also known as bauxite) containing 50% alumina. Aluminum existing in minerals in this form is also one of the most abundant metal elements on our planet.
When aluminum first appeared, it was not immediately applied to people's lives. Later, a number of new products aimed at its unique functions and characteristics gradually came out, and this high-tech material gradually had an increasingly broad market. Although the application history of aluminum is relatively short, the output of aluminum products on the market now far exceeds the sum of other non-ferrous metal products.
Material characteristics: flexible, easy to plastic, easy to alloy, high strength to weight ratio, excellent corrosion resistance, easy to conduct electricity and heat, and recyclable.
Typical uses: vehicle skeleton, aircraft parts, kitchen utensils, packaging and furniture. Aluminum is often used to strengthen some large building structures, such as Cupid statue in Piccadilly Circus in London and the roof of Chrysler Automobile Building in new york.
5. Magnesium alloy-ultra-thin aesthetic design
Magnesium is a very important non-ferrous metal, which is lighter than aluminum and can ... & gt
Question 7: What are the wear-resistant metal materials? Wear-resistant metal materials are as follows:
1, chromium carbide wear-resistant metal materials, such as chromium carbide wear-resistant steel plate produced by Monet Technology Company in Beijing.
2. High manganese steel wear-resistant materials, such as knmn 19cr2.
3. Tungsten carbide metal wear-resistant materials, such as jp8000 sprayed tungsten carbide coating.
Question 8: What are the specific conditions for the chemical composition of general metal materials? If a metal consists of a single metal element, the main chemical component is that metal element, such as copper wire, which is the metal element copper; If it is an alloy, it is two or more elements that synthesize this alloy, such as silicon steel in alloy steel, and the main chemical elements are iron and silicon; In addition, it also contains other impurities, such as carbon and sulfur. For example, the main chemical composition of carbon steel is iron, which contains carbon in addition to iron.
Question 9: What are the characteristics of metal materials? What metallic materials refer to metallic elements or materials with metallic characteristics dominated by metallic elements? Include pure metals, alloy, intermetallic compounds of metallic materials and special metallic materials.
Many mechanical parts and engineering parts work under alternating loads. Under the action of alternating load, although the stress level is lower than the yield limit of the material, after a long period of repeated stress cycles, sudden brittle fracture will also occur, which is the current situation.
machine part
Such as fatigue of metal materials.
The fatigue fracture of metallic materials is characterized by:
(1) The load stress is alternating;
(2) The action time of the load is long;
(3) The fracture is instantaneous;
(4) Both plastic and brittle materials are brittle in the fatigue fracture zone.
Therefore, fatigue fracture is the most common and dangerous fracture form in engineering.
According to different conditions, the fatigue phenomenon of metal materials can be divided into the following types:
(1) High-cycle fatigue: refers to the fatigue with stress cycle exceeding 100000 under the condition of low stress (working stress is lower than the yield limit of materials, even lower than the elastic limit). This is the most common fatigue failure. High cycle fatigue is generally called fatigue.
⑵ Low cycle fatigue: refers to fatigue with stress cycle below 10000~ 100000 under high stress (working stress is close to the yield limit of materials) or high strain conditions. Because alternating plastic strain plays a major role in this fatigue failure, it is also called plastic fatigue or strain fatigue.
⑶ Thermal fatigue: refers to fatigue damage caused by repeated thermal stress caused by temperature change.
⑷ Corrosion fatigue: refers to the fatigue damage of machine parts under the combined action of alternating load and corrosive media (such as acid, alkali, seawater and active gas).
5. Contact fatigue: This refers to the contact surface of machine parts, which is pitted and peeled off or the surface is crushed and peeled off under the repeated action of contact stress, resulting in the failure of the parts.
plastically
Plasticity refers to the permanent deformation (plastic deformation) of metal materials without fracture under the action of external force.
plastic deformation
Poor ability. When a metal material is stretched, its length and cross-sectional area will change. Therefore, the plasticity of metal can be measured by two indicators: elongation of length (elongation) and shrinkage of section (shrinkage of section).
The greater the elongation and area shrinkage of metal materials, the better the plasticity of materials, that is, materials can withstand greater plastic deformation without damage. Generally, metal materials with elongation greater than 5% are called plastic materials (such as low carbon steel), and metal materials with elongation less than 5% are called brittle materials (such as gray cast iron). Materials with good plasticity can produce plastic deformation in a larger macro range, and at the same time, metal materials can be strengthened through plastic deformation, thus improving the strength of materials and ensuring the safe use of parts. In addition, materials with good plasticity can be successfully processed in some molding processes, such as stamping, cold bending, cold drawing and straightening. Therefore, when selecting metal materials as mechanical parts, certain plasticity indexes must be met.
keep patience
Main forms of corrosion of building metals
① Uniform corrosion. The corrosion of the metal surface makes the cross section thinner. Therefore, the annual average thickness loss value is often used as an index of corrosion performance (corrosion rate). Steel is generally uniformly corroded in the atmosphere.
② Cavitation erosion. Metal corrosion is punctate, forming deep pits. The occurrence of pitting corrosion is related to the properties of metal and its medium. Cavitation is easy to occur in the medium containing chloride salt. The maximum hole depth is often used as an evaluation index of hole erosion. Pitting corrosion is mostly considered in pipeline corrosion.
③ Galvanic corrosion. Corrosion at different metal contacts due to different potentials.
④ crevice corrosion. Due to the difference of medium composition and concentration in different parts, local corrosion of metal surface often occurs in cracks or other hidden areas.
⑤ Stress corrosion. Under the combined action of corrosive medium and high tensile stress, the metal surface corrodes and propagates inward into microcracks, which often leads to sudden fracture. This kind of damage may occur on high-strength steel bars (steel wires) in concrete.
difficulty
Hardness indicates the ability of a material to resist hard objects pressing into its surface. It is one of the important performance indexes of metal materials. Generally, the higher the hardness, the better the wear resistance. Commonly used hardness indexes include Brinell hardness, Rockwell hardness and Vickers hardness.
1. Brinell hardness (HB) Hardened steel balls with a certain size (general diameter 10mm) are pressed into the surface of the material with a certain load (general 3000kg) and kept for a period of time. The ratio of load to indentation area after unloading is Brinell hardness (HB), and the unit is kilogram force/square millimeter (N/mm2).
2......& gt& gt
Question 10: Which models of aluminum plates contain which metal materials? 1×××× series aluminum plates: for 1050, 1060, 1 100. In all series, 1×××× series belongs to the series with the most aluminum content. The purity can reach above 99.00%.
2××××× series aluminum plates: represent 2A 16(LY 16) and 2A06(LY6). 2×××× series aluminum plates are characterized by high hardness, in which the content of primary copper is the highest, about 3-5%.
The main component of 3××××× series aluminum plates is manganese, and the content is between 1.0- 1.5%.
4××××× series aluminum plates: the representative is 4A0 1. 4××××× series aluminum plates belong to high silicon content series.
5×××××× series aluminum plates: representing 5052, 5005, 5083 and 5A05 series. 5 ××××× series aluminum plates belong to the commonly used alloy aluminum plate series. The main element is magnesium, and the content of magnesium is between 3 and 5%.
6××××× series aluminum plate: stands for 606 1. It mainly contains magnesium and silicon.
7××××× series aluminum plate: stands for 7075. It mainly contains zinc.
8××××× series aluminum plates: 80 1 1 aluminum plates are commonly used and belong to other series.