Supply 1065 spring steel rod, 1065 spring steel rod

Spring steel has high tensile strength, elastic limit, and high fatigue strength. In terms of technology, spring steel is required to have a certain degree of hardenability, be difficult to decarburize, and have good surface quality. Carbon spring steel is a high-quality carbon structural steel with a carbon content within the range. Alloy spring steel is mainly silicon-manganese steel. Their carbon content is slightly lower, and their performance is mainly improved by increasing the silicon content. There are also alloy spring steels of chrome, tungsten, and vanadium. In recent years, combined with my country's resources and according to the requirements of new technologies in automobile and tractor design, new steel types have been developed based on silicon-manganese steel with boron, niobium, molybdenum and other elements added, which has extended the service life of the spring and improved the quality of the spring. . Production process Generally, spring steel can be produced with electric furnace, open-hearth furnace or oxygen converter to produce high-quality spring steel with good quality or special properties, and can be refined with electroslag furnace or vacuum furnace. The specified content range of main elements such as carbon, manganese, and silicon in spring steel is narrow, and the chemical composition must be strictly controlled during smelting. When the silicon content is high, defects such as bubbles are easily formed, and white spots are easily produced when the steel ingot is not cooled properly after forging and rolling. Therefore, the raw materials used for smelting must be dry, gases and inclusions must be removed as much as possible, and overheating of molten steel must be avoided. Special attention must be paid to decarburization and surface quality during the rolling process of spring steel. When the steel surface is severely decarburized, the fatigue limit of the steel will be significantly reduced. For high silicon spring steel such as 3, care should be taken to avoid graphitization. Therefore, the rolling stop temperature should not be too low (℃) during hot processing to avoid staying too long in the temperature range (~℃) where graphitization is easier to form. After the spring is made, shot peening can produce residual compressive stress on the surface of the spring to offset part of the working stress on the surface and inhibit the formation of surface cracks, which can significantly increase the fatigue limit of the spring. Heat treatment specifications Steel grade Quenching temperature Quenching medium hardness requirements Tempering temperature Cooling medium hardness requirements Application range - water or oil - spiral springs and spring washers with a wire diameter smaller than - oil or water - water - - plate springs and - coils Spring - oil - water - leaf springs and coil springs with larger and more important cross-sections - oil - high-temperature springs that work below - oil - water thickness - characteristics and applications of leaf springs
. , can get very high Strength, hardness, yield ratio, but small hardenability, poor heat resistance, and low ability to withstand dynamic and fatigue loads are widely used, but they are mostly used for small springs with low operating temperatures or less important larger springs. spring. For example, the springs used in automobiles, tractors, railway vehicles and general machinery have simple composition, better hardenability, comprehensive mechanical properties, decarburization and other process properties than carbon steel, but they are sensitive to overheating, have temper brittleness, and are prone to cracks after quenching. The price is low and the dosage is large. It can manufacture various small-section flat springs, round springs, springs, etc. It can also manufacture valve springs, spring rings, shock absorbers, clutch reeds, brake springs, etc. . , , high silicon content (the upper limit is up to .), high strength and good elasticity. Good anti-tempering stability. Easy to decarburize and graphitize. Hardenability is not high. The main type of spring steel has a wide range of uses. Manufacture of various springs, such as leaf springs, coil springs for automobiles, locomotives, tractors, cylinder safety valve springs and some important springs that work under high stress and severely worn springs. Because it contains boron, its hardenability can be significantly improved for the front and rear suspension springs and auxiliary springs of light and medium-sized vehicles. The steel grade independently developed in my country has better hardenability, comprehensive mechanical properties and fatigue properties than steel. It is mainly used to manufacture leaf springs for medium and small cars. It has good use effect and can also be used to manufacture other leaf springs and coil springs with medium cross-section sizes. .High strength spring steel. It has high hardenability and good heat treatment process performance. Because of their high strength, important large-scale springs with large loads should be processed in time to eliminate internal stress after rolling the springs. It can be used to manufacture steam turbine seal springs, adjusting springs, condenser support springs, high-pressure water pump disc springs, etc. Steel also makes extremely important springs, such as conventional weapon retrieval hook springs and crusher springs. . The outstanding advantages are good hardenability, in addition, good thermal processing properties, comprehensive mechanical properties, and anti-decarburization properties. Various important springs with large cross-sections, such as large leaf springs and coil springs for automobiles and motorcycles. . It has the highest hardenability among all existing spring steels. The mechanical properties and anti-tempering stability are also good for the super large springs used in large civil construction, heavy vehicles, machinery, etc. The thickness of the steel plate can reach more than 3, and the diameter of the round steel can exceed 3. A small amount of vanadium improves the elasticity, strength, yield ratio and elastic reduction resistance, refines the grains, and reduces the tendency of decarburization. The carbon content is small, and the plasticity and toughness are better than other spring steels. Various important coil springs with high hardenability and good fatigue performance are especially suitable for springs with high working stress amplitude and strict fatigue performance requirements, such as valve springs, injector springs, cylinder expansion rings, safety valve springs, etc. Quenching It has high permeability ratio and other similar performance to larger leaf springs, coil springs, torsion springs, etc. .High strength heat resistant spring steel. Hardenability is very good. The high temperature resistance to relaxation and thermal processing properties are also very good. Heat-resistant springs with working temperatures below ~ ~, such as turbine main steam valve springs, steam seal spring sheets, boiler safety valve springs, boiler disc valve springs, etc. Research has shown that the strength level of traditional spring steel is difficult to meet the requirements of modern industrial development. As we all know, the mechanical properties of spring steel depend on the heat treatment process under the premise of ensuring material quality, and the heat treatment process should also be determined based on the materials used. The high strength of spring steel An important way is to give full play to the role of alloying elements to achieve the best alloying effect. . Heat-treated spring steel requires higher strength and fatigue limit, and is generally used in the state of quenching + medium temperature tempering to obtain a higher elastic limit. Heat treatment technology has a crucial impact on the intrinsic quality of springs. Therefore, how to further improve the fatigue life of springs requires further research, especially chemical surface modification heat treatment, shot peening, etc., which all have an important impact on the fatigue life of springs. In order to further strengthen the surface strength of the valve spring, increase the compressive stress and improve the fatigue life, after the valve spring is formed, it must be further processed by nitriding, low-temperature liquid carbonitriding or sulfur nitriding, and then shot peened. For example, Japan compares oil-quenched steel wires that have been carbonitrided at ℃ and low temperature with medium-temperature tempering at ℃, and their fatigue limits can be improved. The infiltration of nitrogen not only eliminates the adverse effects of decarburization, but also increases the residual compressive stress. At the same time, the high-temperature strength of the valve spring after nitriding and low-temperature liquid carbonitriding is improved. The deformation amount at ℃ is. (The specified value is .), the deformation amount at ℃ is., which improves the thermal stability and anti-relaxation stability of the valve spring, but the nitriding and liquid carbonitriding time should be strictly controlled, otherwise reticular sulfides and reticular nitrides will be formed , but will reduce its fatigue strength. To improve the strength of the valve spring, you can also choose shot peening. According to production practice, there are two kinds of shot peening available for valve spring shot peening. One has a diameter of . and its microhardness is . , and the other has a diameter of . and its microhardness is . .,Three times of shot peening can achieve a better strengthening effect and improve the surface quality. . Alloying carbon is the main strengthening element in steel, and its impact on spring steel is often greater than other alloying elements. According to the usage requirements, the spring steel material should be medium-high carbon alloy steel. The spring steel commonly used in countries around the world contains most of the carbon content. In order to overcome the problem of reduced toughness and plasticity after the strength of spring steel is increased, there is also a trend to reduce the carbon content. Our country has conducted in-depth research on low-carbon martensitic spring steel, such as b, etc., whose carbon content is around .3. Practice has shown that these spring steels can be used in the lath-like martensite structure of low-temperature tempering, and have sufficient strength and excellent comprehensive mechanical properties, especially excellent plasticity and toughness. Several high-strength spring steels researched and developed in Japan, such as , , , , , etc., have carbon contents of around . The main role of alloying elements in spring steel is to improve mechanical properties, improve process performance and impart certain special properties (such as high temperature resistance, corrosion resistance), etc. Many spring steels use silicon as the main alloy element, which is the alloy element that has the greatest impact on spring reduction resistance. This is mainly due to the strong solid solution strengthening effect of silicon. At the same time, silicon can inhibit the crystal nucleation of cementite during the tempering process. Form and grow, changing the number, size and shape of carbides precipitated during tempering, and improving the tempering stability of steel. At present, the domestic steel grades are .~., which is the spring steel with the highest silicon content in the existing standards. However, if the silicon content is too high, it will promote the decarburization and graphitization tendency of the steel during rolling and heat treatment, and make smelting difficult and easy to form inclusions. Therefore, the use of spring steel with excessive silicon content still needs to be cautious. Since chromium can significantly improve the hardenability of steel, prevent the tendency of graphitization during spheroidizing annealing, and reduce the decarburization layer, it is a commonly used alloy element in spring steel. Spring steel with chromium as the main strengthening element is widely used. . Manganese is the most effective alloying element to improve hardenability. It dissolves into ferrite and has a solid solubility effect. Research shows that it must be greater than ., so that the core of the spring steel can completely turn into martensite during quenching. However, when it exceeds ., the toughness decreases significantly, which should be given priority when selecting spring steel.