A, stainless steel hot-rolled steel plate
Stainless steel hot-rolled steel plate is produced by hot rolling process of stainless steel plate. Thickness is not greater than 3mm for thin plate, thickness greater than 3mm for thick plate. It is used for the manufacture of corrosion-resistant parts, containers and equipment in the chemical, petroleum, machinery, shipbuilding and other industries. Its classification and grades are as follows: 1. Austenitic steel (1) 1Cr17Mn6Ni15N; (2) 1Cr18Mn8Ni5N; (3) 1Cr18Ni9; (4) 1Cr18Ni9Si3; (5) 0Cr18Ni9; (6) 00Cr19Ni10; (7) 0Cr19Ni9N; (8) 0Cr19Ni10NbN ; (9) 00Cr18Ni10N; (10) 1Cr18Ni12; (11) 0Cr23Ni13; (12) 0Cr25Ni20; (13) 0Cr17Ni12Mo2; (14) 00Cr17Ni14Mo2; (15) 0Cr17Ni12Mo2N; (16) 00Cr17Ni13Mo2N; (17) 1Cr18Ni12Mo2Ti; (18) 0Cr18Ni12Mo2Ti; (19) 1Cr18Ni12Mo3Ti; (20) 0Cr18Ni12Mo3Ti; (21) 0Cr18Ni12Mo2Cu2; (22) 00Cr18Ni14Mo2Cu2; (23) 0Cr19Ni13Mo3; (24) 00Cr19Ni13Mo3; (25) 0Cr18Ni16Mo5; (26) 1Cr18Ni9Ti; (27) 0Cr18Ni10Ti; (28) 0Cr18Ni11Nb; (29) 0Cr18Ni13Si4 2. austenitic- -ferritic section steel (30) 0Cr26Ni5Mo2; (31) 00Cr18Ni5Mo3Si2;
3. ferritic section steel (32) 0Cr13Al; (33) 00Cr12; (34) 1Cr15; (35) 1Cr17; (36) 1Cr17Mo; (37) 00Cr17Mo; (38) 00Cr18Mo2; (39) 00Cr30Mo2; (40) 00Cr27Mo 4. Martensitic steel (41) 1Cr12; (42) 0Cr13; (43); 1Cr13; (44) 2Cr13; (45) 3Cr13; (46) 4Cr13; (47) 3Cr16; (48 ) 7Cr17 5. Precipitation hardening steel (49) 0Cr17Ni7Al
Two, stainless steel cold-rolled steel plate
Stainless steel cold-rolled steel plate is a cold-rolled stainless steel plate produced by the cold-rolling process, the thickness of less than 3mm for the sheet, the thickness of more than 3mm for the thick plate. Used to make corrosion-resistant parts, petroleum, chemical pipelines, containers, medical equipment, ship equipment, etc., its classification and grade are as follows:
1. Austenitic steel In addition to the same as the hot-rolled part (29 kinds), there are: (1) 2Cr13Mn9Ni4 (2) 1Cr17Ni7 (3) 1Cr17Ni8
2. austenitic --In addition to the same as the hot-rolled portion (2 types), there are also: (1) 1Cr18Ni11Si4AlTi (2) 1Cr21Ni5Ti
3. Ferritic sections In addition to the same as the hot-rolled portion (9 types), there are also: 00Cr17
4. Maraging sections In addition to the hot-rolled part of the same (8 kinds), there are 1Cr17Ni2
5. Precipitation hardening steel: the same as the hot-rolled part
Three, ferrite, austenite, martensite Introduction
We all know that the solid metals and alloys are crystals, that is, the atoms in its internal arrangement according to a certain law, the arrangement of the way there are generally three kinds of that is: the body-centered cubic lattice structure, face-centered cubic lattice structure and dense hexagonal lattice structure. Metal is composed of polycrystals, its polycrystalline structure is formed in the process of metal crystallization. The iron that makes up the iron-carbon alloys has two lattice structures: α-iron with a body-centered cubic lattice structure below 910°C, and Υ-iron with a face-centered cubic lattice structure above 910°C. If carbon atoms are crowded into the iron lattice structure, the carbon atoms are forced into the lattice structure, and the carbon atoms are forced out. If the carbon atoms crowded into the iron lattice, without destroying the lattice structure of iron, such a substance is called solid solution. Carbon dissolves into α--Fe to form a solid solution called ferrite, its ability to dissolve carbon is very low, the maximum solubility does not exceed 0.02%. While carbon dissolved to Υ - iron in the formation of solid solution is called austenite, its ability to dissolve carbon is higher, up to 2%. Austenite is the high temperature phase of iron-carbon alloys. Steel at high temperatures when the formation of austenite, supercooled to below 727 ℃ into an unstable supercooled austenite. Such as a great cooling rate subcooled to 230 ℃ below, then the carbon atoms in the austenite has no diffusion possibility, austenite will be directly into a carbon oversaturated alpha solid solution, known as martensite. Due to the carbon oversaturation, caused by martensite strength and hardness, plasticity reduction, brittleness increases. The corrosion resistance of stainless steel is mainly derived from chromium. Experiments have proved that only when the chromium content of more than 12% of the steel corrosion resistance will be greatly improved, therefore, the chromium content of stainless steel are generally not less than 12%. Due to the increase in chromium content, the organization of the steel also has a great impact, when the chromium content is high and the carbon content is very small, chromium will make the iron-carbon equilibrium, the Υ-phase area on the graph shrinks, or even disappears, this stainless steel for the ferrite organizational structure, the heating does not occur when the phase change, known as ferrite-type stainless steel. When the chromium content is low (but higher than 12%), the carbon content is high, the alloy is very easy to form martensite when cooled from a high temperature, so this type of steel is called martensitic stainless steel. Nickel can extend the Υ-phase region, so that the steel has an austenitic organization. If the nickel content is enough to make the steel at room temperature also has an austenitic organizational structure, it is called this steel for austenitic stainless steel.
Four, stainless steel in various fields of application
1. 1960 - 1999 about 40 years, stainless steel production in Western countries from 2.15 million tons to 17.28 million tons, an increase of about 8 times, the average annual growth rate of about 5.5 percent. Stainless steel is mainly used in the kitchen, home appliances, transportation, construction, civil engineering fields. In the kitchen appliances are mainly washing tank and electrical, gas water heaters, home appliances are mainly automatic washing machine drum. From the point of view of environmental protection such as energy saving and recycling, the demand for stainless steel is expected to expand further. In the field of transportation there are mainly railway vehicles and automobile exhaust systems, stainless steel for exhaust systems in each vehicle is about 20-30kg, the world's annual demand of about 1 million tons, which is the largest application area of stainless steel. In the field of construction, the recent sharp increase in demand, such as: Singapore subway station guards, the use of about 5000 tons of stainless steel exterior decorative materials. Then, such as Japan after 1980, stainless steel used in the construction industry grew about four times, mainly used as roofing, building interior and exterior decorative and structural materials. 80's, in Japan's coastal areas, the use of 304-type uncoated material as a roofing material, from the rust considerations, and gradually transformed into the use of stainless steel painted. In the 1990s, high Cr ferritic stainless steel with high corrosion resistance of more than 20% was developed and used as roofing materials, and various surface finishing technologies were developed for aesthetic purposes. In the civil engineering field, stainless steel is used for dam suction towers in Japan. In the cold regions of Europe and the United States, salt is spread to prevent freezing of highways and bridges, which accelerates the corrosion of steel bars, so stainless steel bars are used. Roads in North America, the last three years, about 40 places to use stainless steel rebar, the use of 200-1000 tons each, the future of stainless steel in the field of the market will make a difference.
2. The key to future expansion of stainless steel applications is environmental protection, long life and IT popularization. With regard to environmental protection, first of all, from the point of view of atmospheric environmental protection, used to inhibit the occurrence of dioxins in high-temperature waste incineration equipment, LNG power generation equipment and the use of coal in high-efficiency power generation equipment heat-resistant, high-temperature corrosion-resistant stainless steel demand will expand. Stainless steel will also be used in the battery shells of fuel cell vehicles, which are expected to be put into practical use in the early 21st century. From the point of view of water quality and environmental protection, stainless steel with excellent corrosion resistance will also expand demand in water supply and drainage treatment equipment. Regarding long life, the use of stainless steel is increasing in facilities such as bridges, highways, and tunnels that already exist in Europe, and it is expected that this trend will spread throughout the world. In Japan, the life span of general residential buildings is particularly short at 20-30 years, and disposal of waste materials has become a major problem. Recently, buildings with a life expectancy of 100 years have begun to appear, so the demand for materials with excellent durability will increase. From the viewpoint of global environmental protection, it is necessary to explore ways to reduce maintenance costs at the design stage when new concepts are introduced, in order to reduce the amount of waste materials for civil engineering and construction while reducing the lifespan of buildings. Regarding the popularization of IT, in the process of the development and popularization of IT, functional materials play a great role in the hardware of the equipment, and the demand for high-precision, high-functionality materials is very large. For example, in cell phones and microcomputer components, the flexible application of stainless steel's high strength, elasticity and non-magnetic properties, making the expansion of stainless steel applications. There are also in the semiconductor and a variety of substrate manufacturing equipment, with good cleanliness and durability of stainless steel plays an important role. Stainless steel has a variety of excellent properties not found in other metals, and is a material with excellent durability and recyclability, and will be used in a wide variety of fields in the future in response to the changing times.
Common steel product terminology
1. Carbon steel
Carbon steel, also known as carbon steel, is an iron-carbon alloy containing less than 2% carbon WC. Carbon steel in addition to carbon generally contains a small amount of silicon, manganese, sulfur, phosphorus according to
Use of carbon steel can be divided into carbon structural steel, carbon tool steel and free-cutting structural steel three categories. Carbon structural steel is divided into building structural steel and machine
manufacturing structural steel two kinds of carbon content can be divided into low-carbon steel (WC ≤ 0.25%), medium-carbon steel (WC0.25% - 0.6%) and high-carbon steel
(WC>0.6%) According to the phosphorus, sulfur content can be divided into Carbon steel can be divided into ordinary carbon steel (containing phosphorus, sulfur higher), high-quality carbon steel (containing phosphorus, sulfur lower
and advanced quality steel (containing phosphorus, sulfur lower) general carbon steel in the carbon content is higher, the higher the hardness, the higher the strength is also higher, but the plasticity is lower
2. Carbon structural steel
This type of steel to ensure that the main mechanical properties, so its grade reflects the mechanical properties, with Q + digital said, which "Q" for the yield point "yield" character
Hanyu Pinyin character first, the number of yield point value, such as Q275 yield point of 275Mpa. If the brand number labeled letters A, B, C, D,
that is, just now the quality of different grades of steel
. p>It means that just now the quality of different grades, containing the amount of S, P is reduced in turn, the quality of steel in order to improve. If labeled in the grade after the letter "F" is
boiling steel, labeled "b" for semi-sedentary steel, not labeled "F" or "b "for the sedentary steel. For example, Q235-A-F indicates that the yield point of 235Mpa
A grade boiling steel, Q235-C indicates that the yield point of 235Mpa C grade sedentary steel carbon structural steel in general are not heat-treated, and in the state of supply
state direct use. Usually Q195, Q215, Q235 steel carbon quality fraction is low, good welding performance, plasticity, toughness, good, have a certain strength, often
rolled into thin plates, reinforcing bars, welded steel tubes, etc., used for bridges, buildings and other structures and the manufacture of ordinary screws, nuts and other parts.Q255 and Q275 steel carbon
mass fraction is slightly higher, higher strength, plasticity, toughness, cross good. Can be welded, usually rolled forming steel, bar steel and steel plate for structural parts and
Manufacture of simple machinery rods, gears, couplings, a little and other parts
3. High-quality structural steel
This type of steel must be guaranteed at the same time the chemical composition and mechanical properties. Its grade is the use of two digits to indicate the average carbon mass fraction of steel in the million
number (WC × 10,000). For example, 45 steel that steel in the average carbon mass fraction of 0.45%; 08 steel that steel in the average carbon mass fraction of
0.08% High-quality carbon structural steel is mainly used in the manufacture of machine parts. They are generally heat-treated to improve mechanical properties. According to the carbon mass fraction
different, there are different uses. 08, 08F, 10, 10F steel, high plasticity, toughness, has excellent cold-forming properties and welding performance, often cold rolled into
thin plate, used to make instrument shells, automobiles and tractors on the cold stamping, such as automobile body, tractor cabs, etc.; 15, 20, 25 steel is used to
Production size called small, light load, surface requirements wear-resistant, heart strength requirements of the carburized parts, such as piston pins, samples, etc.; 30, 35,
40, 45, 50 steel heat-treated with good overall mechanical properties, that is, high strength and high plasticity, toughness, for the production of shafts
type of parts, for example, 40, 45 steel is commonly used in the manufacture of automobiles, tractors, crankshafts, tractor cabs, and other cold stamping parts. 40, 45 steel is commonly used in the manufacture of automobiles, tractors, crankshafts, connecting rods, general machine tool spindles, machine tools, gears and other shaft parts not subject to large
; 55, 60, 65 steel heat treatment has a high elasticity limit, commonly used in the production of the load is not large, the size of the smaller springs, such as pressure regulating
and speed springs, plunger springs, cold rolled springs and so on
4. Carbon tool steel
Carbon tool steel is basically no alloying elements of high-carbon steel, carbon content in the range of 0.65% - 1.35%, its low production costs, raw material sources
easy to obtain, good cutting and machining, heat treatment can be obtained after the high hardness and high abrasion resistance, so it is a widely used steel used in the manufacture of various
kinds of cutting edge, molds, but the steel of this type of red hardness, that is, when the working temperature is greater than 250 ℃, the red hardness is poor, that is, when the red hardness is poor, the red hardness is poor, that is, when the red hardness is poor. When the working temperature is greater than 250 ℃, the hardness and wear resistance of steel will fall sharply and lose
to work. In addition, carbon tool steel, such as made of larger parts is not easy to harden, and prone to deformation and cracks
5. easy cutting structural steel
easy cutting structural steel is in the steel to add some elements that make steel brittle, so that the steel cutting is easy to brittle broken into chips, thus helping to improve the cutting
cutting speed and extend the life of the tool. Make steel brittle element is mainly sulfur, in the ordinary low alloy free cutting structural steel used in lead, tellurium, bismuth and other elements
Element The sulfur content of this steel WS in the range of 0.08% -0.03%, manganese content WMn in the range of 0.60% -1.55%. Sulfur and manganese in steel in the form of manganese sulfide
state exists, manganese sulfide is very brittle and lubricating effect, so that cutting easy to break, and help to improve the quality of processed surfaces
6. Alloy Steel
In addition to the steel containing iron, carbon and a small amount of unavoidable silicon, manganese, phosphorus, sulfur, but also contains a certain amount of alloying elements, steel alloying
Golden Elements Silicon, manganese, molybdenum, nickel, chitin, alum, titanium, niobium, boron, lead, rare earths and so on one or more of these steels, this steel is called alloy steel countries
the alloy steel system, with their respective resources, production and use of different conditions, foreign countries in the past has been the development of nickel, chitin steel system, our country is
found that silicon, manganese, vanadium, titanium, niobium, boron, lead, rare earths, mainly the alloy steel system Alloy steel in the total steel production accounted for about ten percent,
generally smelted in the electric furnace according to the use of alloy steel can be divided into eight categories, they are: alloy structural steel, spring steel, bearing steel, alloy steel
tool steel, high-speed tool steel, stainless steel, heat-resistant non-skinned steel, silicon steel for electricians
7. Ordinary low alloy steel
ordinary Low-alloy steel is an ordinary alloy steel containing a small amount of alloying elements (in most cases the total amount of W total not more than 3%). The strength of this steel
degree is relatively high, the overall performance is relatively good, and has a corrosion-resistant, wear-resistant, low-temperature resistance, as well as better cutting performance, welding performance in a large number of savings
scarce alloying elements under the conditions of the general 1 tons of low alloy steel can be topped 1.2-1.3 tons of carbon steel to use, and its service life and the scope of use is much
far more than the carbon steel. Ordinary low alloy steel can be smelted in the general smelting method in the flat furnace, converter smelting, the cost is also close to the carbon steel
8. Engineering structural alloy steel
This refers to alloy steel used for engineering and construction structures, including weldable high-strength alloy structural steel, alloy reinforcing steel, alloy steel for railroads,
Geological and petroleum drilling alloy steel, pressure vessels alloy steel, high-manganese wear-resistant steel. Manganese wear-resistant steel. This type of steel is used for engineering and construction structural parts, in the alloy steel
, the total alloy content of such steel is low, but the production and use of a larger
9. Mechanical structure alloy steel
This type of steel refers to the alloy steel suitable for the manufacture of machinery and mechanical parts. It is based on high-quality carbon steel, the appropriate addition of one or several
kinds of alloying elements, used to improve the strength, toughness and hardenability of steel. This type of steel is usually heat-treated for use. Mainly includes commonly used alloy
structural steel and alloy spring steel two categories, including tempering treatment of alloy steel, surface hardening treatment of alloy steel, cold plastic molding alloy steel
. According to the chemical composition of the basic composition system can be divided into Mn-system steel, SiMn-system steel, Cr-system steel, CrMo-system steel, CrNiMo-system steel, Ni-system steel, B-system steel
etc.
10. spring steel
Springs are used in the shock, vibration, or long term cross-stress, so the requirements of the spring steel has a high tensile strength, elasticity limit, high fatigue strength
. In the process requires a certain degree of hardenability of spring steel, not easy to decarburize, good surface quality carbon spring steel that contains carbon WC in 0.6% -0.9% of the paradigm
within the scope of the na?ve carbon structural steel. Alloy spring steel is mainly silicon-manganese steel, their carbon content is slightly lower, mainly by increasing the silicon content Wsi to improve
performance; in addition there are chrome, tungsten, vanadium alloy spring steel. In recent years, combined with China's resources, and according to the automobile, tractor design new technology
Requests, developed in the silicomanganese steel based on the addition of boron, niobium, molybdenum and other elements of the new steel to extend the service life of the spring, improve the quality of the spring
11.Bearing steel
bearing steel is used to manufacture the balls, rollers, and bearing rings of steel. Bearings in the work is subjected to great pressure and friction, so the requirements
bearing steel has a high and uniform hardness and wear resistance, as well as high elastic limit. The uniformity of the chemical composition of the bearing steel, non-metallic inclusions
content and distribution, carbide distribution and other requirements are very strict bearing steel, also known as high-carbon chitin steel, containing carbon Wc for about 1%, containing chitin Wcr for
0.5%-1.65%. Bearing steel is also divided into high-carbon chrome bearing steel, no chrome bearing steel, carburized bearing steel, stainless bearing steel, high-temperature bearing steel and antimagnetic
Six major categories of bearing steel
12.Electrical silicon steel
Silicon steel is mainly used in the manufacture of electrical appliances industrial silicon steel sheet. Silicon steel sheet is a large amount of steel used in the manufacture of motors and transformers According to the chemical
Composition of silicon steel can be divided into low-silicon steel and high-silicon steel. Low silicon steel silicon content Wsi1.0%-2.5%, mainly used in the manufacture of motors; high silicon steel carbon content
Wsi3.0%-4.5%, generally used in the manufacture of transformers. Their carbon content Wc ≤
0.06%-0.08%
13. Bridge steel
Railway or highway bridges to withstand the impact load of the vehicle, the bridge steel requires a certain degree of strength, toughness and good fatigue resistance, and the
steel surface quality requirements are high. Bridge steel is often used in alkaline flat furnace sedentary steel, recently successfully used ordinary low alloy steel such as 16 manganese, 15 manganese
alum nitrogen, etc.
14. Boiler steel
Boiler steel mainly refers to the materials used to manufacture the superheater, the main steam pipe and the boiler fire chamber with the heating surface. Performance requirements for boiler steel is mainly
good welding performance, a certain high-temperature strength and resistance to alkali corrosion, oxidation resistance. Commonly used boiler steel has a flat furnace smelting of low-carbon sedentary steel or electric
Furnace smelting of low carbon steel, carbon content Wc in the range of 0.16% -0.26%. Manufacturing high-pressure boilers are applied to pearlite heat-resistant steel or austenitic heat-resistant steel
. In recent years, the use of ordinary low alloy steel boiler construction, such as 12 manganese, 15 manganese vanadium, 18 manganese molybdenum niobium, etc.
15. Stainless steel
Stainless acid-resistant steel is referred to as stainless steel, which is made up of stainless steel and acid-resistant steel two large parts of the composition of the steel, in short, the ability to resist corrosion of atmospheric corrosion of the steel is called stainless steel, and the ability to resist the corrosion of the chemical medium is called acid-resistant steel. Generally speaking, the steel containing chitin Wcr more than 12% has the characteristics of stainless steel
Stainless steel according to the microstructure after heat treatment can be divided into five categories: namely, ferrite stainless steel, martensitic stainless steel, austenitic stainless steel, austenitic
- ferritic stainless steel and precipitated carbonized stainless steel
16. heat-resistant steel
At high temperatures. With oxidation resistance and the main enough high-temperature strength and good heat-resistant properties of the steel is called heat-resistant steel. Heat-resistant steel, including oxidation-resistant
steel and heat-strengthened steel two categories. Oxidation-resistant steel is also referred to as non-skinning steel. Hot steel refers to the high temperature with good oxidation resistance and high temperature strength of the steel. Heat-resistant steel is mainly used for parts that are used for a long time at high temperatures