• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: A sliding part for internal combustion engines is provided to substantially reduce abrasion phenomena generated due to friction by forming stable compounds using Fe-Cr-B alloy so that the compounds are not reacted with other metals. CONSTITUTION: In a sliding part for internal combustion engines using metal consisted of iron or copper, titanium, aluminum or alloy thereof as a main body, the sliding part for internal combustion engines is characterized in that an amorphous coating layer comprising 40.0 to 50.0 wt.% of Cr, 2.5 to 6.5 wt.% of B, 0.5 to 5.0 wt.% of Si and 0.0 to 0.5 wt.% of C, 0.0 to 5.0 wt.% of Ni, Mo, Cu, Ti, V, Zr, Nb, Hf, Ta, W or a mixture thereof and a balance of Fe and inevitable impurities is formed on the surface of the main body, wherein the amorphous coating layer is a mixed layer of amorphous phase material and carbide formed by spray coating a mixture prepared by adding 0 to 40 vol.% of carbide particles of WC, TiC, TaC or a mixture thereof to a spray coating material on the surface of the main body of the sliding part for internal combustion engines.
    公开号:KR20040070448A
    申请号:KR1020040023289
    申请日:2004-04-06
    公开日:2004-08-09
    发明作者:김강형
    申请人:김강형；
    IPC主号:
    专利说明:

    Coated sliding parts for internal combustion engine}
    [1] The present invention relates to a piston crown of a large engine used in ships, automobiles and heavy equipment, a ring ring groove formed on an outer circumference of the piston crown, a piston ring fitted to the groove, and The present invention relates to a sliding component such as a cylinder bore, a cylinder liner or a cylinder inner wall, and other piston rods in which friction occurs, and more particularly, to form a coating layer of Fe-Cr-B alloy on the surface of the sliding component, but to have an amorphous structure. The present invention relates to a sliding part for an internal combustion engine having better wear resistance and a smaller coefficient of friction. Fe-Cr-B amorphous coating in the present invention is similar to the thermal expansion coefficient of iron or cast iron, which is the main material of the engine, the base structure is not only tough and strong, but also has the advantage of improving the durability life of the sliding parts with a low friction coefficient have.
    [2] First, the characteristics required by the sliding parts of a large engine such as a ship, an automobile, or heavy equipment pursued by the present invention are as follows.
    [3] Diesel engines are also referred to as reciprocating internal combustion engines, diesel engines, and compression ignition engines, which operate by compression and ignition of light or heavy oil as fuel. It is an internal combustion engine that obtains power by inhaling and compressing air into a cylinder to obtain a high temperature and high pressure, and then spraying liquid fuel to spontaneously ignite the piston to operate the piston. Low quality fuel can also be used, which has the advantage of low fuel costs. Diesel engines, like gasoline engines, are composed of cylinders, pistons, crankshafts, and the like. Air is sucked into the cylinder to compress it, and the fuel is spontaneously ignited by injecting fuel from the fuel injection valve into the high temperature and high pressure air. The fuel is injected from the plunger type pump, the needle valve is in close contact with the valve seat by the spring, and when the fuel reaches the predetermined pressure by the pump, the fuel is automatically pushed up and the fuel is in the form of fine particles into the cylinder. Sprayed. Next, when spontaneously complexed and exploded by the high temperature in the cylinder, the pressure in the cylinder rises and pushes the piston to work. As with a gasoline engine, there are two types of diesel engines, two-cycle type and four-cycle type, and both single-acting and double-acting types are used. Horsepower ranges from several horsepower to around 35,000 horsepower. There is also a case where a supercharger is installed to produce a great horsepower. Depending on the shape of the combustion chamber, there are single chamber and inlet chamber, and the single chamber is called direct injection by injecting fuel into the combustion chamber surrounded by the piston head and cylinder cover. Large engines are usually direct injection.
    [4] Diesel engines can use fuels such as heavy oil and diesel fuel, which are cheaper than gasoline engines, and have low fuel consumption and thus low operating costs. It is also easy to start, making it the most widely used internal combustion engine. Large ships are used as main engines for large ships, with more than 5,000 horsepower and more than two cycles. Medium is used for power generation and ships. Two cycles are also used for more than 1,000 horsepower, but four cycles are generally used. Small ones are widely used for automobiles, railway vehicles, small ships, and construction organizations.
    [5] The piston repeats the up and down motion, which consists of acceleration, deceleration, and stopping at an unprecedented speed in the engine cylinder. As the piston reciprocates in the middle of the cylinder, the expansion stroke is momentarily expanded by the combustion gas, which can be at least 2000 ℃, and receives a force of up to 3 to 4 tons (5 tons for the turbo engine) and transmits it to the connecting rod. Do it.
    [6] Therefore, the piston should first be light for the purpose of reducing the inertial force generated by the reciprocating motion, and should be strong and heat-transfer while having low thermal deformation to support the expansion force. Large ship engines mainly use cast iron for various problems related to the stiffness of the engine block. Cast iron has the advantage that graphite in the tissue gives lubricity.
    [7] The piston crown, also called the piston head, corresponds to the head of the piston, forms part of the engine combustion chamber, transfers high temperature heat to the cylinder wall and connects the explosive force with the piston pin through the piston lower body. It serves to deliver to the load.
    [8] The piston crown has an annular ring in which a piston ring, such as a compression ring for maintaining the airtightness of the combustion gas, and an oil ring for scraping oil from the wall of the combustion chamber to reduce oil consumption and transferring the heat of the piston to the cylinder. A plurality of piston ring grooves are formed.
    [9] In particular, when used for a marine diesel engine, the piston ring abuts against the piston ring groove and on the other side abuts the cylinder bore of the engine. Thus, the piston ring requires a large wear resistance at the boundary interface towards the cylinder bore, because a large friction occurs when the engine is operated at this interface. Thus, the piston ring must have an inherent tensile and elastic force, which causes the piston ring to be in contact with the cylinder bore and continuously press outwardly.
    [10] In addition, when the engine explodes, the piston ring is urged radially outward against the cylinder bore by a considerable force, thereby increasing the stress. In addition, the high temperature in the engine and the heat generated by the contact between the piston ring and the cylinder liner lower the yield strength of the materials and increase the softening rate. Ring grooves are areas where wear is severely caused by repeated contact with the ring. Likewise, piston rods tend to wear the surface badly due to friction with the seal.
    [11] During engine operation, the materials of the piston ring and the cylinder liner are exposed to significant corrosive environments due to high temperatures in the areas where local contact is made and temperature differences in other areas.
    [12] The piston rings currently in use are generally made of cast iron blanks, which meet the basic requirements of the material in terms of strength and elasticity. However, this blank is not wear resistant to the surface in contact with the cylinder bore. Cast iron lacks the thermal stability required at high temperatures and, therefore, piston ring blanks composed of cast iron require a high wear resistant layer as the surface most exposed to wear.
    [13] The cylinder of fuel combustion and explosion is blocked by the head upwards and the piston crown below. The inner surface of the cylinder, which forms the combustion chamber together with the cylinder cover and piston, is called a liner. The cylinder cover is in close contact with the upper part of the cylinder block and is assembled by inserting about half into the bore of the block so that it can freely expand downward when heated during engine operation. It is. There are several micropores in the cylinder liner between the micropores of the cylinder block, which are opened when the piston is at the bottom dead center, and these micropores are inclined from the center of the liner so that the microgas can pivot in the liner. .
    [14] Sliding parts of the piston and cylinder are made by casting except for the piston rod, and due to the internal bubbles formed during casting, the structure is not dense, the rigidity is poor, and the surface is not smooth.
    [15] Nitriding, PVD, and CVD methods are applied to improve the wear resistance and low friction coefficient of the sliding parts exposed to excessive friction and excessive sliding conditions, or wear-resistant high alloy steel materials are used to secure wear resistance. There is a method of performing a surface hardening treatment. However, such a method has a disadvantage that the film is not only brittle, but also brittle, and easily destroyed at high pressure.
    [16] In Japanese Patent Laid-Open No. 6081952, the contents of forming a composite coating film on the surface by forming carbonitrides and oxynitrides by coating Cr-N-O films for the production of piston rings and sliding materials. Korean Patent No. 326686 discloses a wear resistant coating provided on a substrate surface of a sliding member and composed of a composition of chromium and nitrogen, wherein the coating surface in contact with the substrate surface is made of chromium nitride, and from the substrate surface to the coating surface. The patent is for a gradual increase in chromium content.
    [17] Japanese Patent Laid-Open No. 11216582 introduces a technique of forming a Fe-Cr-Ni alloy layer by irradiating a laser beam to a Cr + Ni plating layer. In another Japanese Patent Publication No. 9019757, a method of manufacturing and inserting a cylinder liner of aluminum-silicon is introduced. Another Japanese Laid-Open Patent Publication No. 57179354 discloses a method of coating a piston head with Teflon, and Japanese Laid-Open Patent Publication No. 3264754 forms a thin film of MoS 2 + Teflon coating to increase sliding wear resistance between the cylinder inner wall or the piston. Japanese Patent Laid-Open No. 1031970 shows a method of coating a film in which Si powder particles and fluorine resin are mixed on the surface of a piston and a piston ring groove.
    [18] However, this method is not only expensive, but also has low rigidity at high temperatures, and thus has a disadvantage in that it cannot be long lasted in a high frictional environment such as a large diesel engine. In addition, since the work must be performed at a high temperature of 1000 ° C. or more during surface hardening treatment, problems such as a decrease in dimensional accuracy and a decrease in hardness of the base material due to thermal deformation occur.
    [19] Another method recently used is a coating method for forming a diamond phase. U.S. Patent No. 49774498 discloses a method of coating a thin diamond film or diamond-like particles on a piston and a piston ring for the improvement of an internal combustion engine. The coating thickness of the synthetic diamond forms a film having a thickness of 0.01-1 mm. It is. However, it is weak to impact and industrially has a disadvantage that is easily destroyed when a thin film of 2-3㎛ or less occurs when mechanical friction and impact occurs.
    [20] As another method, a method of realizing a low friction coefficient through gas adsorption on silicon oxide (SiO 2 ) formed on a sliding surface made of an amorphous hard carbon-hydrogen-silicon film of Japanese Patent Laid-Open No. 3-240957 is shown. However, this silicon oxide is formed on the surface of the hydrogenated amorphous carbon film containing Si in the film in advance by sliding with the counterpart and is not present in the film from the beginning. Therefore, in the initial stage of sliding, not only does it take a long time to achieve a low friction coefficient due to the large coefficient of friction, but also easily breaks due to the brittleness of the membrane when an impact is applied due to the jerk phenomenon caused by the reduction of exhaust gas during rapid deceleration in the engine. There is this.
    [21] Recently, in order to overcome these problems, a method of forming and using a coating layer using chromium or chromium-compound materials has been generally used. In general, a large ship sailing periodically checks and measures various parts of the engine. Especially, a cylinder has a great effect on sailing, so it always pays attention to the degree of wear. When moored at sea, the engine is always checked and repaired to the worn cylinders, in most cases hard chrome plating.
    [22] Korean Patent No. 0162046 shows a piston ring having a dual structure in which a piston ring for an internal combustion engine forms a hard chromium plating layer on an outer circumferential sliding surface, and forms a tungsten disulfide (WS 2 ) layer again on the hard chromium plating layer. Japanese Patent Laid-Open Nos. 1115298, 6037145, 61043253, 2031081, 3255273 and the like introduce a technique of forming a porous chromium plating layer on a cylinder liner such as steel, an aluminum alloy, or stainless steel.
    [23] Chromium has an excellent corrosion resistance because the Cr 2 O 3 oxide film is dense and strong. However, since it is easily reacted with iron, continuous friction with iron such as a cylinder liner destroys the Cr 2 O 3 oxide film and causes adhesion wear. The iron-bonded part is difficult to form a dense and strong oxide film, and friction with the cylinder liner causes severe wear such as scoring in a short time. Engines using low-quality kerosene containing sulfur, such as ships, tend to form low corrosion resistance CrS, Cr 2 S 3, etc., which leads to severe wear and deterioration of the overall performance, and the need for replacement over time. The problem is that the work must be repeated over and over. Some ships carry spare cylinders in advance, but interrupting and exchanging voyages is not cumbersome.
    [24] Accordingly, the present invention has been made to solve the above-mentioned problems, by providing a sliding component for an internal combustion engine coated with a composition material having an amorphous phase to achieve excellent wear resistance and low friction coefficient, thereby providing a piston crown, a ring groove, a piston It is an object of the present invention to provide a sliding part for an internal combustion engine in which a better wear resistance is formed on a surface layer of a ring and a cylinder liner or a cylinder inner surface and a low friction coefficient is shown.
    [25] Features of the present invention for achieving the above object in the sliding parts of a large internal combustion engine,
    [26] On the surface of the sliding parts made of iron or copper, titanium, aluminum or their alloys, by weight% Cr 40.0-50.0%, B 2.5-6.5%, Si 0.5-5.0%, C0.0-0.5% and Ni, The composition of Cu, Mo, Ti, V, Zr, Nb, Hf, Ta, W is added alone or in combination of 0.0 to 5.0%, and the remainder is composed of Fe and impurities which are inevitably contained in the surface of the sliding part. Coating on a provides a sliding part with excellent wear resistance and a low coefficient of friction.
    [27] Looking at each of the chemical components constituting the amorphous phase on the surface of the sliding part of the present invention in detail.
    [28] It is composed of Cr 40.0 ~ 50.0%, B 2.5 ~ 6.5%, Si 0.5 ~ 5.0% by weight, and C 0.0 ~ 0.5% and Ni, Mo, Cu, Ti, V, Zr, Nb, Hf, Ta, W The composition is characterized by having an amorphous phase by coating alone or in combination with 0.0 to 5.0%, the remainder being coated with a composition consisting of Fe and unavoidable impurities. In addition, in the present invention, by spraying 0 to 40% of carbide particles such as WC, TiC, and TaC to the thermal spraying material alone or in combination for an extreme grinding wear environment, an amorphous phase and a carbide mixed phase are formed to improve wear resistance through cemented carbide particles. .
    [29] In the present invention, Cr is an important element for improving corrosion resistance and abrasion resistance, and forms a phase corresponding to Fe and an intermetallic compound to facilitate formation of an amorphous phase during quenching. If it is less than 40.0%, the γ phase may appear, and if it is more than 50.0%, excess Cr may separate and interfere with the formation of the amorphous phase. Preferably, the composition of 43.0% to 46.0% makes it easy to obtain an amorphous phase.
    [30] B is the most important amorphous phase forming element in the present invention. It is an element that easily combines with Fe and Cr to form an intermetallic compound, and is well equipped with requirements for forming an amorphous phase. When the Fe-Cr alloy containing B is quenched during solidification, it does not form an intermetallic compound and transforms into an amorphous phase. However, at less than 2.5%, γFe or αFe may appear, which may interfere with amorphous phase formation. If the amount exceeds 6.5%, the excess B forms a weak intermetallic compound, so it is limited. Preferably, the composition is formed at 5.6 to 6.2% so that the amorphous phase is easily formed.
    [31] Si is added for the effect of enhancing the solid solution of the B and other elements as well as strengthening the matrix structure at the high temperature of the matrix solid solution and contact with oxygen generated during coating. If it is less than 0.5%, there is no effect, and in 5% or more, an (epsilon) phase and (eta) phase may appear, and it suppresses. Preferably, the composition of 1.75% to 2.25% is effective in forming an amorphous phase and strengthening the matrix and inhibiting oxidation.
    [32] C has the effect of strengthening the matrix structure and improving the abrasion resistance by making B, Cr and the like carbides, and can be added as needed. However, at 0.5% or higher, it may cause cracks during cooling after coating, so suppress it.
    [33] Cu has an effect of lowering the alloy to lower the melting point to improve fusion and to increase the bonding property, and is added as necessary. However, exceeding 5.0% is limited because it may cause segregation or deterioration of corrosion resistance.
    [34] Ni, Ti, V, Zr, Nb, Hf, Ta, W combine with B or C to form carbohydrates to strengthen the matrix structure, such as spalling, fitting, and chipping. If necessary, it is added below 5.0% because of the effect of increasing resistance to thermal fatigue. If this is exceeded, there is an effect to harm the amorphous phase formation beyond the employment limit.
    [35] Hereinafter, an embodiment of the present invention will be described. However, the following examples do not limit the scope of the present invention.
    [36] Example
    [37] The SCM440 disc, 100 mm in diameter and 6 mm thick, was quenched and tempered to obtain a hardness of HRC 30. This is blasted with chrome steel shortball to form a shallow dimple face on the surface, and Cr 45.3%, B 5.9%, Si 1.8%, C 0.12%, Cu 2.1%, Mn 0.8%, Ni 0.5%, Mo 0.5% and the rest is Fe The composed composition was spray coated.
    [38] The spray coating method was a DJ (Diamond Jet) HVOF system, which used oxygen as the primary gas and propylene, hydrogen or propane as the secondary gas. At this time, the flame temperature was about 3000 ° C., and the scattering rate of the molten particles was sprayed at a rate of about 2,000 m / sec, and the cured layer having a porosity of 5% or less and a hardness of about HV 1,2000 was 0.13 to 0.15 mm thick. Got it. The coating layer was polished with alumina stone to finish the surface roughness at the level of ▽▽▽ (1.2S).
    [39] The anti-wear comparison test was performed by using a pin-on-disc method with a hard chromium-plated disc with a thickness of about 30 μm.
    [40] The pin used the SCM440 round bar with the hardness of HRC32 through quenching and tempering, and the edges were prevented by performing 45 chamfers with a diameter of 6mm (area 28.3mm 2 ). The rotation speed was 1.86 m / min, the rotation diameter was 25 mm, and the load was fixed at 20 kg / cm 2 to measure the endurance endurance. To prevent errors due to premature delamination, the slide surface of the original specimens was tested with a greased cloth.
    [41] As a result of testing each of the three discs, scoring wear occurred in 170, 192, and 198 sec. However, the coating specimens of the present invention generated scoring at 452, 495, and 512 sec.
    [42] In addition, a pin on V-block test was conducted using the Falex tester and test method specified in ASTM D-2670, D-2625, D-3233, and D-5620. At this time, the pin was used to process the SCM440 round bar was processed to the final 1/4 inch diameter using a hardness of HRC32 through quenching and tempering. Forming the coating layer was processed 0.15mm less than the diameter and then coated and polished to finally 1/4 inch. Hard chromium plating was 35 탆 thick after plating and polishing. The V block quenched and tempered the SCM440 material to form a V-shaped groove in the pin-shaped cylinder, the diameter of the pin was 1/2 inch. Both the pin and the block were polished and the surface roughness of the pin was ▽▽▽ (1.2S). The load on the pin was 1000lbs (454kg) and the speed was 293rpm, and it was lubricated to the extent that the general bearing grease was wiped off with a cloth. As a result of three measurements under the above conditions, the hard chromium plated pins were sintered at 35, 49, and 53 sec. In the coating material of the present invention, 247, 285, and 323 sec were shown.
    [43] As described above, the present invention does not have to travel or operate for a long time due to excessive friction and corrosion of the existing sliding parts, and eliminates the need to replace the piston parts or cylinders by performing chrome plating from time to time, and at the same time, strong wear resistance and a low coefficient of friction Due to the sliding parts having a composition has an effect that can be driven to the engine stably.
    [44] In particular, compared with the conventional chromium plating, the chromium plating easily reacts with iron, so that the film is easily destroyed, whereas in the present invention, the alloy of Fe-Cr-B forms a stable compound and thus does not react with other metals. The wear phenomenon due to the effect is significantly reduced.
    权利要求:
    Claims (2)
    [1" claim-type="Currently amended] In a sliding part of an internal combustion engine using a metal made of iron or copper, titanium, aluminum, or an alloy thereof as a main body, Cr 40.0 to 50.0%, B 2.5 to 6.5%, Si 0.5 to 5.0% by weight on the surface of the main body Consisting of 0.0 ~ 0.5% of C, Ni, Mo, Cu, Ti, V, Zr, Nb, Hf, Ta, W alone or in combination with 0.0 ~ 5.0% and the rest is composed of Fe and unavoidable impurities A sliding component for an internal combustion engine, characterized in that to form an amorphous coating layer by coating with a composition.
    [2" claim-type="Currently amended] The internal coating of claim 1, wherein the amorphous coating layer has a layer in which an amorphous phase and a carbide mixed phase are formed by thermally spraying by adding 0-40% of carbide particles such as WC, TiC, and TaC to the thermal spraying material alone or in combination. Sliding parts for engines.
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    同族专利:
    公开号 | 公开日
    KR100543675B1|2006-01-23|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2004-04-06|Application filed by 김강형
    2004-04-06|Priority to KR1020040023289A
    2004-08-09|Publication of KR20040070448A
    2006-01-23|Application granted
    2006-01-23|Publication of KR100543675B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR1020040023289A|KR100543675B1|2004-04-06|2004-04-06|Coated sliding parts for internal combustion engine|
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