48 results about "Ledeburite" patented technology

The invention discloses an improved Cr8 steel roll and a preparation method thereof. Based on the Cr5 steel, the Cr8 steel roll also comprises microalloying Nb and RE, wherein Nb is mainly used for refining the crystalline grain, and RE is mainly used for purifying molten steel. The Cr8 steel roll comprises the following components: 0.50-0.65% of C, less than or equal to 1.0% of Si, less than or equal to 0.60% of Mn, less than or equal to 0.020% of S, less than or equal to 0.020% of P, 7.5-8.5% of Cr, 0.70-1.40% of Mo, less than or equal to 0.50% of V, 0.005-0.20% of Nb, 0.003-0.02% of RE, and the balance of Fe and impurities. By combining solidification refining, deformation recrystalization refining and thermal treatment refining, the method refines the tissue of a high chrome ledeburite die steel and obtains fine plate martensite with the length less than 30micron and width less than 0.5micron. Due to rare earth modification, carbide segregation is reduced, and the morphology of the included foreign substances and eutectic carbide is improved. Due to the adoption of proper thermal treatment technology, compared with Cr5 steel, the Cr8 steel roll not only has higher toughness, but also improves the abrasion performance, and greatly prolongs the service life.

Disclosed is a cast iron material, especially a ledeburite cast iron material which has a high carbide content of at least 15.0 percent by weight and is provided with a characteristic, free, evenly distributed graphite embodiment that can comprise flake graphite and/or vermicular graphite and/or nodular graphite. The basic matrix can be embodied in a pearlitic and/or bainitic and/or martensitic manner according to the application thereof (diameter (D) of the seal of the running gear, peripheral velocity). The thermal conductivity of the inventive material is three to four times greater than that of white cast materials as a result of the high graphite content, thus advantageously preventing seals of running gears from fretting in case of great peripheral velocities (>5 m/s) and large diameters (D>600 mm) of the seals. Additionally, the high carbide content of at least 15 percent by weight provides for good resistance to wear while additional alloying elements such as chromium, vanadium, molybdenum, and nickel provide the material with adequate resistance to corrosion. The disclosed ledeburite cast iron material featuring an evenly distributed graphite embodiment can be used for producing axial face seals and cylinder hushes, for example.

The invention particularly discloses high chromium ledeburite cold work die steel with high tenacity and high abrasive resistance, and a preparation method thereof. The problems that the existing D2 cold work die steel easily generates serious carbide segregation so as to result in low tenacity, small gaps and raptures are solved. The high chromium ledeburite cold work die steel with high tenacity and high abrasive resistance is prepared from the following raw materials by mass percent: 1.40-1.65% of C, no more than 0.60% of Si, no more than 0.60% of Mn, no more than 0.020% of S, no more than 0.020% of P, 8-13.00% of Cr, 0.70-1.20% of Mo, 0.20-1.00% of V, 0.005-0.20% of Nb, 0.003-0.02% of RE, no more than 0.25% of Ni, no more than 0.30% of Cu, and the balance of Fe and impurities. The high chromium ledeburite cold work die steel is excellent in overall performance, and can replace cold work die steel such as Cr12MoV, D2 steel and the like, the tenacity and the abrasive resistance of the die are improved, and the service life is greatly prolonged. Thus, the use cost is reduced, the usable range is expanded, and the problems of poor tenacity, tipping or rapture, low wear resistance and the like in special service environments such as large impact load, high work speed, high accuracy, long service life and the like can be effectively solved.

A high-performance semi-metal brake sheet material without asbestos consists of 5-30% ledeburite-phase fortified iron-base alloy powder, 5-20% pure copper powder or bronze powder, 5-25% nanometer budicyan rubber powder, 5-25% modified phenolic resin, 0.5-2% dithiuram sulfide, 0.5-2% tetramethyl trisulfide thiuram improver, 5-20% glass fiber or/and 5-20% steel fiber or/and 1-10% natural bast fiber, 1-10% carbon fiber composite additive, 1-10% nanometer aluminum oxide and other bulking filler, 1-10% flake-shaped graphite, 1-12% zirconium sulfate, 0.3-3% sulfide and 0.5-3% boron nitride. It can endure 350-400 DEG C temperature, its friction coefficient is between 0.35-0.45 and has excellent thermal attenuation performance and long life.

The invention provides an accurate heat treatment quenching technology of a high-carbon high-chromium tool steel precise part and belongs to the field of heat treatment of tool steel materials. The accurate heat treatment quenching technology is provided for a two-tool-edge stamping part in a precise stamping die, wherein the material of the part is high-carbon high-chromium ledeburite cold work die steel ASSAB XW-5 imported from Sweden, the main alloy ingredients of the high-carbon high-chromium ledeburite cold work die steel ASSAB XW-5 comprise 2.05% of C, 12.5% of Cr, 1.3% of W, 0.8% of Moand 0.3% of Si. According to the accurate heat treatment quenching technology, based on different workpiece hardness requirements, different tempering temperatures are adopted, so that a small designed hardness difference needed by two tool edges of the precise stamping die can be achieved, different temperature keeping times are adopted for different workpiece thicknesses, so that the hardenability of the material is reliably guaranteed, the crystal structure in the material can be accurately controlled to be refined, uniform and stable, and the part can be good in wear resistance, long in service life, high in reliability and stable in dimension and meets the use demands for a precise part. The accurate heat treatment quenching technology is mainly implemented through the following stepsand technical scheme that (1) workpieces with the thickness difference smaller than 5 mm are placed in a quenching furnace and are preheated to 150 DEG C in two steps; (2) the workpieces are heated to the quenching temperature and keep the temperature for the time of t in two steps in the quenching furnace; (3) the workpieces are discharged from the furnace and air cooled to 50-70 DEG C; (4) theworkpieces are fed into a tempering furnace to be heated to T DEG C for tempering and keep the temperature for the time of t twice, and then the workpieces are discharged from the tempering furnace and air cooled (please refer to the figure 1).

The invention relates to a heat treatment method for a ledeburitic steel cold roll, in particular to a differential quenching method for a large-diameter whole ledeburitic steel cold roll, solving the problem that the existing large-diameter whole ledeburitic steel cold roll is easily ruptured after being quenched. The method comprises the following steps: selecting a pre-heat temperature to perform isothermal preheating; quickly heating to a quenching temperature, and preserving the temperature; selecting a cooling temperature to perform isothermal cooling; and cooling in the air, wherein the range of the preheat temperature is more than the critical transition point of complete austenitizing temperature or/and less than the actual quenching temperature 30 DEG C, and the range of the cooling temperature is more than the martensite point and less than the martensite point plus 100 DEG C. In the method, the problem that the existing large-diameter whole ledeburitic steel cold roll is easily cracked after being quenched can be solved through a reasonable design, the whole body is completely quenched and hardened, the hardness of a working layer reaches 60 to 67 HRC, and the hardnessgradient between the cold roll center and the surface layer is less than 10HRC.

The invention discloses a manufacturing method of a high-wear-resistance compression roller shell made of ledeburite steel. The manufacturing method comprises the following steps of 1, feeding; 2, forging; 3, annealing; 4, machining; 5, quenching and low-temperature tempering; and 6, grinding an inner hole; in the first step, a compression roller shell blank is integrally forged by using the ledeburite steel, and feeding is carried out by using a sawing machine according to the weight required by the process; in the second step, raw materials are heated in a natural gas furnace, sectional heating is adopted, two forging equipment are used for forging, drawing-out and upsetting in three directions are adopted, and the total forging ratio is larger than 8. The method comprises the steps thatthe compression roller shell blank is integrally forged by using the ledeburite steel, quenching and low-temperature tempering heat treatment are carried out after machining; the metallographic structure of a final finished product is tempered martensite, carbide and retained austenite, the carbide comprises eutectic carbide and eutectoid carbide, the wear resistance of a compression roller shellis improved by utilizing the high wear resistance of the eutectic carbide, and the service life of the compression roller shell is prolonged.

Material and method for the production of material with isotropic, mechanical properties and improved wear resistance and high hardness potential. Method includes producing in a powder metallurgical (PM) method a slug or ingot from a material of ledeburite tool steel alloy, and subjecting one of the slug or ingot or a semi-finished product produced from the slug or ingot to full annealing at a temperature of over 1100° C., but at least 10° C. below the fusing temperature of the lowest melting structure phase with a duration of over 12 hrs. In this manner, an average carbide phase size of the material is increased by at least 65%, a surface shape of the material is rounded and a matrix is homogenized. Method further includes subsequently processing the material into thermally tempered tools with high wear resistance occurs or into parts to which abrasive stress is applied.

The invention discloses powder metallurgical tool steel for an automobile separation shifting fork. The tool steel is prepared from the following raw materials weighed in parts by weight: 75 to 78 parts of iron powder, 20 to 25 parts of 316L austenitic stainless steel powder, 1 to 2 parts of diboron trioxide, 0.2 to 0.4 part of chromium powder, 0.005 to 0.01 part of cerium oxide, 0.2 to 0.6 part of copper sulfide, 0.2 to 0.4 part of molybdenum powder, 0.2 to 0.4 part of nickel powder, 0.2 to 0.4 part of zircon powder, 0.002 to 0.003 part of strontium powder, 0.001 to 0.002 part of germanium disulfide and 0.45 to 0.5 part of a polymerizing agent. According to the powder metallurgical tool steel disclosed by the invention, cementite and high-temperature ledeburite are formed inside a material during the processing; meanwhile, some crystal lattices inside the material are distorted, so the strength of alloy is greatly enhanced; moreover, nitrogen atoms penetrate into the surface of the material, so the surface hardness and the wear resistance are improved; meanwhile, the fatigue strength, the corrosion resistance and the impact resistance are also improved; the automobile separation shifting fork manufactured from the material are resistant to corrosion and impact for a long time, and the service life is greatly prolonged.

The invention relates to the technical field of cast alloy iron, in particular to novel anti-attrition and wear resistant cast iron and a preparation method thereof. The novel anti-attrition and wearresistant cast iron is prepared from the following components in percent by mass: 2.8-3.8% of C, 1.8-3.0% of Si, 0.5-2.0% of Mn, 0.3-0.8% of P, 1.2-3.0% of Cr, 0.4-2.0% of Ni, 0.1-1.0% of Mo, 0.2-2.0%of V, 0.5-3.0% of Cu, 0.1-0.5% of Ti, less than or equal to 0.08% of S and the balance Fe. Based on common cast iron components, various alloy elements are added, so that the tissues of the cast ironcontain fine ledeburite eutectic alloys. By adding phosphorus, binary and ternary phosphorus eutectic tissues exist. The eutectic tissues form grid frameworks in the cast iron and the frames are distributed in a pearlite matrix to play an anti-attribution role. Fine flake graphite in the grids can form oil storage holes, thereby playing the anti-wear role.

The invention discloses a heat treatment and quenching process for high-carbon high-chromium tool steel. The material is high-carbon high-chromium ledeburite cold-worked tool steel with the steel number of ASSAB XW-5 imported from Sweden, and the tool steel mainly comprises, by weight percentage, 2.05% of carbon, 12.5% of chromium, 1.3% of wolfram, 0.8% of molybdenum and 0.3% of silicon. The heattreatment and quenching process comprises the following steps that (1), workpieces are put into a quenching furnace to be preheated to 150 DEG C; (2), the workpieces are put into the quenching furnacefor two-stage heating until the quenching temperature is 965 DEG C, and then heat preservation is carried out; (3), the workpieces are taken out from the quenching furnace for air-blast quenching until the temperature is 70 DEG C; and (4) the workpieces are placed into a tempering furnace, the workpieces are heated to 280 DEG C, heat preservation and tempering are carried out on the workpieces, the workpieces are taken out from the tempering furnace for air cooling, and then the above procedures in the step (4) is repeated. According to the heat treatment and quenching process, staged heatingand twice tempering are adopted, and therefore the heating is more uniform, the hardenability of the workpieces is improved, the crystal grains can be refined, uniform, stable and reliable, the service life and the mechanical property of the parts are obviously improved, the toughness and the impact resistance of the workpieces are improved, and the use requirements of the precise parts are met.

The ledeburite malleable cast iron with high toughness belongs to the field of casting technology. It is composed of the following raw materials in mass percentage, C 0.07%, Si 0.25%, Mn 0.2%, S 0.01%, P 0.02%, Cr 2.2%, Mo 1.2%, V 0.65%, Nb 0.12%, RE 0.08%, Ni 0.14%, W 0.36%; the rest is Fe and impurities. The composition of the invention is novel, the service life is greatly improved, the use cost is greatly reduced, the use range is expanded, and the large impact load can be effectively solved. Surface carburizing treatment is carried out on it, and surface quenching treatment is carried out after carburizing, and its toughness and fatigue strength have been greatly improved. The stress on the surface is reduced, and the service life of malleable cast iron has been greatly improved, which meets the needs of various stress concentrations and high impact loads.

The invention discloses a high-hardness and high-abrasion-resistance high tungsten ledeburite gear steel and a preparation method thereof and belongs to the technical field of powder metallurgy. The high-hardness and high-abrasion-resistance high tungsten ledeburite gear steel is composed of the following raw materials of, by mass, 1. 8% of C, 0.5% of Si, 0.25% of Mn, 0.015% of S, 0.025% of P, 2.5% of Cr, 1.25% of Mo, 0.8% of V, 0.16% of Nb, 0.05% of Re, 0.12% of Ni, 0.30% of W and the balance Fe and impurities. The high-hardness and high-abrasion-resistance high tungsten ledeburite gear steel can replace cold working die steel such as Cr12MoV steel and D2 steel, the toughness and abrasion resistance of a die are improved, the service life is greatly prolonged so as to reduce the use cost and expand the use range, the problems of poor toughness, tipping or breaking and poor abrasion resistance under special use environments such as the large impact load, the high working speed, high precision and the long life can be effectively solved, and the use requirements of multiple high bearing and high rotating speed occasions are met.

The invention discloses abrasion-resistant alloy cast iron, comprising the following components in percentage by weight: 3.1-3.5% of carbon, 1.9-2.5% of silicon, 0.4-0.9% of copper, 0.4-0.6% of manganese, 0.2-0.4% of chromium, 0.1-0.4% of molybdenum, 0.1-0.15% of sulphur, 0.1-0.15% of phosphorus, 0.05-0.2% of vanadium, 0.04-0.07% of boron, and the balance of iron and impurities. Different numbers of cast iron of boron-containing cementite or ledebrite structures in a metallographic structure can be obtained. The micro-hardness of the boron-containing cementite is HV960-1280. The alloy cast iron disclosed by the invention has a special abrasion-resistant structure and the abrasion resistance is greatly improved.

The invention discloses a camshaft argon arc remelting production and machining process. The camshaft machining process includes the following steps that a strip round material is placed on a punch to be cut off; the cut-off round material is placed in a heating device to be preheated, and the round material is heated to 900 DEG C to 1000 DEG C in an induction mode, wherein the heating rate ranges from 70 DEG C/s to 80 DEG C/s; then a preheated camshaft is heated to 1000 DEG C to 1200 DEG C in an induction mode, wherein the heating rate ranges from 50 DEG C/s to 60 DEG C/s; thermal refining is conducted, and hardness is made to range from 28 HRC to 30 HRC; the heated material is placed in a forming die, and the material is formed through punch forging; then under the arc high-temperature effect, tiny molten pools are formed on the surface of a cam through protection of argon laminar flow, after arc transfer, the molten pools are chilled through heat absorption of a workpiece, fine ledeburite tissue is obtained, and turning and deburring are conducted. The grains of the camshaft are fine, abrasion resistance of the camshaft is higher than that of chilled cast iron, mechanization is easy to achieve, quality is stable, the rejection rate is low, and cost is low.

The invention discloses a ledeburite steel compression roller shell with high wear resistance. The raw material of the compression roller shell is ledeburite steel, the ledeburite steel comprises thefollowing components of, in percentage by weight, 1.2%-2.3% of carbon, 3.5%-13% of chromium and the balance silicon, manganese, iron, molybdenum, vanadium, tungsten and impurity elements; representative marks of the ledeburite steel include Cr8, Cr12, Cr5Mo1V, Cr12W, Cr12MoV and Cr12Mo1V1 in GB/T1299-2014; tempered martensite, carbides and retained austenite exist in the metallographic structure of the ledeburite steel compression roller shell; and the carbides comprise eutectic carbides and eutectoid carbides. According to the ledeburite steel compression roller shell, the high wear resistance of the eutectic carbides is utilized to enhance the wear resistance of the compression roller shell, so that the service life of the compression roller shell is prolonged.

The invention provides a method for laser repairing the surface of spheroidal cast iron, comprising the following steps: 1) preparing powder material for laser repairing spheroidal cast iron; 2) pretreating the area to be clad; 3) preheating the base material; 4) Multi-layer cladding is carried out on the damaged part of the surface of the spheroidal cast iron. The single layer thickness of the cladding layer is 1.2-1.3mm. 2mm; 5) After cladding, the nodular cast iron is cooled to room temperature, and the colorant is sprayed to check whether there are crack defects; 6) The cladding repair layer of the nodular cast iron is machined to remove the protruding coating on the outer surface of the damaged part. The cladding area formed by this method has no crack defects and has little thermal influence on the base material. The interface between the cladding layer and the ductile cast iron base material shows a discontinuous melting trend, and the interface is a typical jagged shape. The bonding strength is high and the interface is avoided. Cracks occur due to the formation of continuously transformed ledeburite.

The invention discloses malleable wear-resistant alloy cast iron. The malleable wear-resistant alloy cast iron comprises the following components by weight percent: 2.4-2.8% of carbon, 1.1-1.5% of silicon, 0.4-0.6% of manganese, 0.15-0.2% of sulfur, 0.8-0.1% of phosphorus, 0.05-0.2% of vanadium, 0.04-0.07% boron and the balance of iron and impurities. The malleable wear-resistant alloy cast iron has both forging machinability and wear resistance. Different amounts of boron-containing cementite or ledeburite in the metallographic structure is formed in the cast iron, wherein the micro-hardness of the boron-containing cementite is HV960-1280. The malleable wear-resistant alloy cast iron has a special wear-resistant structure, thus the wear resistance is extremely increased. In addition, after the cast iron is annealed, the forging machinability becomes good.