Saw blades are in most cases universal, there is no need to choose. But for harder materials, wind steel saw blades are appropriate.
T7, T7A sub***ysis steel. Has good plasticity, toughness and strength, as well as a certain degree of hardness, can withstand vibration and shock loads, but poor cutting ability. Used in the manufacture of shock load is not big, carbylamine requirements with appropriate hardness and wear resistance, and good toughness of the tools, such as forging, chisels, hammers, punches, metal shear knives, reaming drills, steel seals, carpentry tools, wind tools, machine tools, top of the pliers, pliers, drilling and chiseling tools, blunt Branch medical appliances and so on.
T8, T8A *** analyzed steel. Quenching and heating is easy to overheat, deformation is also large, plasticity and strength is relatively low, not suitable for the manufacture of tools to withstand greater impact, but after heat treatment has a higher hardness and wear resistance. Used in the manufacture of cutting edge in the work of the non-hot work, such as woodworking tools, wind tools, pliers tools, simple molds, rivets die, center hole Singijeon and punch mold, cutting steel tools, bearings, cutting tools, aluminum and tin alloy die-casting plates and cores, as well as various types of springs, etc..
T8Mn, T8MnA **** precipitation steel. Has high hardenability and hardness, but lower plasticity and strength. Used in the manufacture of larger cross-section of woodworkers, hand saw blades, engraving tools, rivet punching molds, clockwork, band saw blades, circular saw blades, coal mine chisels, masonry chisels and so on.
T9, T9A over **** analysis steel. Has a high hardness, but lower plasticity and strength. Used in the manufacture of high hardness and a certain degree of toughness of a variety of tigers, such as engraving and printing work, riveting dies, press molds, punches, woodworkers, home machine cutting parts, rock drilling work and casting molds, such as diversion nails.
T10, T10A over **** precipitation steel. Fine grain, in quenching and heating (temperature up to 800 ℃) does not overheat, can still maintain a fine grain organization; quenching steel in the undissolved excess carbide, so has a higher wear resistance than T8, T8A steel, but the toughness is lower.
Used in the manufacture of cutting edges in the work of the tool does not change the heat, not subject to shock loads and has a sharp edge and a little toughness of the tool, such as processing tools for wood, hand crosscutting saws, hand joinery tools, machine joinery tools, machine joinery tools, twist drills, drawing dies, punching molds, cold heading molds, screw cones, reaming tools, thread rolling board, lathe, planer, milling cutter, currency pressure mold, small size Cold edge cutting and punching dies with uniform cross section, low precision and simple shaped chucks, clamping scrapers, hard rock drills, rivet and nail making tools, screwdrivers, files, chisels for engraving, cutting tools for cutting paper and tobacco, and so on.
T11, T11A over **** precipitation steel. Has better overall mechanical properties (such as hardness, wear resistance and toughness, etc.), finer grain, less sensitive to the formation of carbide network of grain growth during heating.
Used in the manufacture of cutting edges in the work of non-thermal tools, such as saws, burins, taps, files, scrapers, clockwork, gauges, reaming drills, plate teeth, cut tobacco cutters, the size of not too big and no sharp changes in the cross-section of the cold-drawn molds and carpentry knives, etc.
T12, T12A over **** precipitation steel. Due to the high carbon content, there are still more excess carbide after quenching, so the hardness and wear resistance is high, but the toughness is low, and quenching deformation is large. Not suitable for the manufacture of high cutting speed and shock loaded tools. Used in the manufacture of tools not subject to shock load, cutting speed is not high, the cutting edge does not change the heat, such as lathes, milling cutters, drills, reamers, reaming drills, taps, tines, scrapers, scrapers, gauges, razor blades, small punches, steel files, saws, hairpin, cutting tobacco cutters, and section size of the small cold cutting edge molds and punching molds, etc..
T13, T13A over **** precipitation steel. Due to the high carbon content, quenched with more excess carbide, so the hardness is higher, toughness is worse; and due to the increase in the number of carbides and uneven distribution, so the mechanical properties are poor. Not suitable for the manufacture of cutting tools to withstand impact loads and higher speeds.
Used in the manufacture of non-impact load, but requires a very high hardness of the metal cutting tools, such as razors, scrapers, drawing tools, files, engraving tools, drills, as well as hard rock processing tools and carving tools.
High-speed steel
1. Overview
High-speed steel is also known as wind steel or sharp steel, meaning that it hardens when quenched even when cooled in air and is very sharp. It is a complex composition of alloy steel, containing tungsten, molybdenum, chromium, vanadium and other carbide-forming elements. The total alloying elements amount to about 10 to 25%. It can maintain high hardness, HRC can be above 60, even under high heat generated by high-speed cutting (about 500℃). This is the most important characteristic of high-speed steel - red hardness. Carbon tool steel after quenching and low temperature tempering, at room temperature although there is a very high hardness, but when the temperature is higher than 200 ℃, the hardness will fall sharply, in 500 ℃ hardness has fallen to the degree similar to the annealed state, the complete loss of the ability to cut metal, which limits the carbon tool steel production cutting tools with. And high-speed steel due to good red hardness, make up for the fatal shortcomings of carbon tool steel, can be used to manufacture cutting tools.
High-speed steel heat treatment process is more complex, must go through a series of processes such as annealing, quenching, tempering. The purpose of annealing is to eliminate stress, reduce hardness, so that the microstructure is uniform, easy to quench. Annealing temperature is generally 860 ~ 880 ℃. Quenching is generally divided into two stages due to its poor thermal conductivity. First in 800 ~ 850 ℃ preheating (so as not to cause large thermal stress), and then quickly heated to the quenching temperature of 1220 ~ 1250 ℃, after the oil cooling. Factories are using salt furnace heating. After quenching because the internal organization still retains a portion (about 30%) of the residual austenite is not transformed into martensite, affecting the performance of high-speed steel. In order to make the residual austenite transformation, to further improve the hardness and wear resistance, generally 2 to 3 times tempering, tempering temperature 560 ℃, each holding time 1 hour.
(1) production and manufacturing methods: usually used in the production of electric furnaces, recently has been used in the production of powder metallurgy method of high-speed steel, so that the carbide is a very fine particles evenly distributed in the matrix, improving the service life.
(2) use: used in the manufacture of various cutting tools. Such as turning tools, cobalt head, hob, machine saw blades and demanding molds.
2. The main production plant
China's Dalian Steel, Chongqing Steel, Shanghai Steel is the main production of high-speed steel production plant.
3. Main import production countries
China's main imports from Japan, Russia, Germany, Brazil and other countries