413results about How to "Improve red hardness" patented technology

The invention discloses a method for preparing a composite powder for 3D printing, and belongs to the technical field of material additive manufacturing. The method comprises the following steps: S1, executing mechanical mixing on a metal matrix phase powder and a nano-ceramic strengthening phase powder to obtain a mixed powder; and S2, executing a ball-milling process on the mixed powder to obtain an alloyed powder, wherein a ball-milling medium used in ball-milling is spherical and has a diameter of 6-10mm, a ball-to-powder ratio is 8: 1 to 10: 1, a distance from a ball-milling tank to a rotary centre is 15-30cm, a rotational speed is 150-200rpm, a ball-milling time is 6-8h, and the composite powder is obtained. The invention further provides a method for using the composite powder prepared by the above-mentioned method for 3D printing forming for parts. The composite powder prepared by the method disclosed by the invention is free from micro-cracks and the problem of supersaturated solid solution, and has no high internal stress; and the parts prepared by virtue of the composite powder disclosed by the invention through a selective laser melting forming method have good comprehensive performance.

The invention discloses high-entropy alloy powder for laser cladding and a preparation method of a cladding layer. The high-entropy alloy powder comprises Ti, Zr, V, Nb, Ta and Mo. In addition, high-entropy alloy powder which comprises Ti, Zr, V, Nb, Ta, Mo and W, high-entropy alloy powder which comprises Ti, Zr, V, Nb, Ta, Mo, W and Cr and the preparation method of the cladding layer of the high-entropy alloy powder for laser cladding are provided. The high-entropy alloy powder mainly comprises two characteristics, namely, the high-entropy effect and the cocktail effect, each kind of powder exerts respective advantages, and therefore the cladding layer with high hardness, high corrosion resistance, excellent tempering softening resisting performance and excellent structure performance is obtained. Metallurgical bonding is formed by an alloy layer and a matrix through laser cladding; the bonding strength of the cladding layer and the matrix is greatly improved, and the heating speed is high; metal of the cladding layer is not prone to being diluted by the matrix; little heat deformation is generated; and therefore the part rejection rate is low.

The invention provides a high wear-resistant alloy for a splitting roller, which is characterized in that the alloy comprises the following constituents by weight percentage: 1.9 to 3.8 percent of C, 6 to 25 percent of W, 6 to 18 percent of Mo, 3 to 8 percent of Cr, 6 to 15 percent of Co, 5 to 15 percent of V, 1.5 to 7.5 percent of Nb, 0.5 to 1.5 percent of Si, 0.3 to 1.2 percent of Mn, 2 to 8 percent of Ni, 0.5 to 2.5 percent of B, less than or equal to 0.05 percent of S, less than or equal to 0.07 percent of P, and the balance being Fe. The invention also provides a method for preparing the high wear-resistant alloy for the splitting roller. The method greatly improves impact toughness while improving the wear resistance of materials, and preparation technology is easy to control and grasp.

The invention relates to cermet containing a Ni-Cr binding agent, belonging to cermet material and aiming at leading the high temperature oxidation resistance of the cermet to be improved. The cermet is made by that TiC, TiN, WC, Mo, Cr3C2, Ni, Cr and powdered graphite are conducted with ball milling mixing, press molding, vacuum degreasing and vacuum sintering; the weight percentage of the compositions are as follows: Ti is more than or equal to 33 and less than or equal to 49, W is more than or equal to 4 and less than or equal to 9, Mo is more than or equal to 11 and less than or equal to 17, Ni is more than or equal to 12 and less than or equal to 34, Cr is more than or equal to 4 and less than or equal to 10.5, C is more than or equal to 7.5 and less than or equal to 11, and N is more than or equal to 2 and less than or equal to 3. The method of the invention comprises the following steps of ball milling mixing, press molding, vacuum degreasing and vacuum sintering. The cermet has good rigidity, red hardness, wear resistance, oxidation resistance, thermal shock resistance and adhesive resistance in hot environment as well as low friction coefficient, and can be used for manufacturing high-speed high-efficiency cutting tools, copper profile hot extrusion dies and parts with heat resistance, corrosion resistance and wear resistance.

The invention relates to a high speed steel tool heat treatment method and the method specifically includes the following steps: high-temperature step quenching steel materials to be treated in a quenching medium at the temperature of 1200-1310 DEG C; after quenching, cooling to room temperature and then low-temperature tempering for 1h at the temperature of 80-100 DEG C; cold treating for 2-3h at the temperature of minus 120-minus 80 DEG C; and finally tempering for 1-1.5h at the temperature of 540-560 DEG C, wherein the quenching medium is selected from calcium chloride saturated water solution, polyglycol water solution, polyving akohol water solution or potassium permanganate quenching liquid. The high speed steel tool heat treatment method is simple in process and saves energy, and compared with traditional technology, the mechanical performance and service life of the high speed steel tool are improved by around 20-40 percent.

The invention relates to the technical field of cemented carbide preparation, in particular to surface-hardened gradient cemented carbide and a preparation method thereof. By adjusting components of an alloy binding phase, the WC crystalline grains in the prepared cemented carbide are small, even in distribution, high in density and remarkable in gradient, the cemented carbide is made to have the more excellent mechanical property, and the red hardness of the cemented carbide is improved. The components and thickness of a gradient layer of the cemented carbide are controlled by adjusting blank formulas, sintering temperature, sintering time and other parameters, the surface layer of the cemented carbide is made to be rich in cubic phase and poor in binding phase, and due to the fact that a transition layer rich in alloying binding phase is arranged below the surface layer, the cemented carbide is excellent in hardness, wear resistance and roughness, and the cemented carbide can be used for metal machining. The cemented carbide prepared through the method has the excellent wear resistance, strength, hardness and toughness at the same time. According to the method, the functional gradient cemented carbide can be produced by slightly modifying existing equipment and processes, and is suitable for industrial production.

The invention discloses boracic high-speed steel with good red hardness, and a preparation method of the boracic high-speed steel. The boracic high-speed steel comprises the following chemical components in percentage by weight: 0.30-0.5% of C, 3.8-5.5% of Cr, 0.9-3.5% of W, 0.9-2.1% of Mo, greater than or equal to 3.5% and less than or equal to 5.0% of (W+2Mo), 0.8-1.2% of Si, 0.3-1.5% of Mn, 3.0-3.5% of B, 0.8-2.6% of Cu, 2.8-3.6% of Al, 0.5-1.0% of V, 0.8-1.6% of Ti, 0.02-0.15% of Ca, 0.03-0.25% of Ce, 0.02-0.18% of N, 0.05-0.3% of Nb, 0.12-0.25% of Mg, 0.04-0.13% of K, 0.05-0.12% of Ca, 0.06-0.15% of Ba, less than or equal to 0.03% of S, less than or equal to 0.04% of P and the balance of Fe and inevitable impurity elements. The preparation method comprises the following steps: smelting waste steel and ferrochrome, subsequently adding copper plates, silicon iron and ferromanganese iron, adjusting the component at a stokehole, after being qualified, raising the temperature to be 1,560-1,620 DEG C, adding calcium-silicon and aluminum for deoxidation, adding ferrotitanium, ferro-boron and aluminum, smelting and discharging outside a furnace, adding a rare earth magnesium alloy and a composite inoculant consisting of metal cerium, Si3N4, VN (Vanadium Nitride), Nb and K, so as to perform inoculation treatment, wherein the molten steel casting temperature is 1,400-1,450 DEG C, keeping the temperature of a cast piece at 920-1,150 DEG C for 2-4 hours, and subsequently performing air cooling.

The invention discloses hot work die steel high in comprehensive performance and a preparation method of the hot work die steel. The hot work die steel comprises the components of, by weight percentage, 0.25-0.35% of C, 0.6-0.8% of Si, 0.8-1.0% of Mn, 3.75-4.5% of Cr, 1.0-1.65% of Mo, 0.01-0.03% of Y, 0.02-0.05% of Ir, 0.01-0.03% of Sr, 0.2-0.6% of V, less than or equal to 0.03% of P, less than orequal to 0.03% of S and the balance Fe. The preparation method comprises the following steps of (1) smelting, (2) refining, (3) VD vacuum degassing, (4) casting, (5) electroslag remelting, (6) forging, (7) annealing and (8) double refining, thereby obtaining the hot work die steel finally. The hot work die steel has good thermostability and can maintain high rigidity under the condition of 700 DEG C, and the rigidity is above HRC45. The prepared hot work die steel has high high-temperature strength, and has relatively high rigidity, and excellent impact toughness and tempering (thermal fatigue) resistance. The hot work die steel has the advantages of optimization in matching ratio, purity in steel quality, structure uniformity, high strength, high toughness, good tempering resistance andthe like, therefore, the service life of the hot work die steel is prolonged.

The invention relates to a preparation method of a graphite material for a continuous casting mold. The preparation method comprises the following steps: crushing, screening and burdening calcined coke, adding mid-temperature pitch, and carrying out mixing, molding, primary roasting, primary dipping, secondary roasting, secondary dipping, third roasting and graphitizing to obtain the product, wherein the particle size range and the content of the calcined coke are that the calcined coke with the particle size which is smaller than or equal to 1.0mm and greater than 0.8mm accounts for 1-2%; the calcined coke with the particle size which is smaller than or equal to 0.8mm and greater than 0.5mm accounts for 31-36%; the calcined coke with the particle size which is greater than 0.075mm and smaller than or equal to 0.5mm accounts for 28-32%; the calcined coke with the particle size which is smaller than 0.075mm accounts for 34-38%; the mixing is divided into dry blending and wet blending; the wet blending comprises the following processes: firstly heating the mid-temperature pitch to 180-230 DEG C, carrying out heat preservation and stirring for 30-60 minutes, and then adding the mid-temperature pitch to aggregate twice to knead, wherein the kneading temperature is 140-150 DEG C.

The present invention relates to high-performance high-speed steel, and particularly to a high-hardness high-wear-resistant powder metallurgy high-speed steel which is manufactured according to a power metallurgy method and contains Al. The high-speed steel is composed of C, Si, Cr, Mo, V, W, Nb, Mn, Co, Al, Fe and impurities. The high-speed steel manufactured according to the technical solution has the following advantages: more than 67.5HRC of quenching-tempering hardness, better red hardness and wear resistance, stronger bending strength and lower cost.

The invention relates to high-toughness hot work die steel and a production method thereof and belongs to the field of alloy steel manufacture. The die steel comprises the components: 0.36-0.45% of C, 0.8-0.95% of Si, 0.7-0.8% of Mn, 4.8-5.5% of Cr, 1.3-1.8% of Mo, 0.8-1.0% of V, 0.3-0.6% of W, 0.4-0.5% of Ni, 0.1-0.2% of Co, 0.08-0.12% of Nb, 0.008-0.012% of RE, less than or equal to 0.003% of S, less than or equal to 0.025% of P and the balance Fe. The production method is implemented according to the following steps: (1) smelting; (2) electroslag remelting; (3) high-temperature homogenizing; (4) forging; (5) blank forging; (6) annealing treatment; and (7) quench tempering. The high-toughness hot work die steel is high in hardness, low in production cost, long in service life and relatively high in toughness, wear resistance and durability.

The invention discloses a manufacturing technology and device for an improved forged steel roller neck high nickel chrome molybdenum alloy cast composite roller. The roller comprises, by mass percent, 3.0%-3.6% of C, 0.60%-1.20% of Si, 0.30%-1.20% of Mn, 3.0%-5.0% of Ni, 1.0%-2.0% of Cr, 0.40%-1.2% of Mo, 0.1%-2% of W, 0.5%-1.0% of Cu, not larger than 0.05% of P, not larger than 0.03% of S, 0.04%-0.06% of Mg, 0.1%-0.3% of Nb, 0.1%-0.30% of Ti, 0.2%-0.6% of V, 0.05%-0.2% of B, 1.5%-2.5% of Ba, 1%-2% of Ca, 1%-3% of Sb, 0.02%-0.18% of N, 1.0%-2.0% of Y/RE and the balance Fe and inevitable micro elements. Yttrium base rare-earth nodulizing and Ba, Ca, and silicon iron composite inoculation are adopted, Nb, Ti, V, B and Sb are added for modification, and the mechanical performance of the roller is improved; by the adoption of the forged steel roller neck, the strength of the roller is improved, an induction heater is adopted to carry out in-mold whole heating casting on a core stick, a water cooled crystallizer is molded, a composite layer interface can be dynamically controlled, the technology is simple, the efficiency is high, power consumption is small, the cost is low, no composition segregation exists, and the service life of the roller is long.

The invention discloses a material of the working layer of an electromagnetic centrifugal casting high speed steel composite roller, the composition mass percentage of which is as follows: 1.8 to 2.5 of C, 3 to 10.0 of W, 2 to 4 of Mo, 4.0 to 7.0 of Cr, 0.5 to 2 of V, 0.03 to 0.5 of RE, less than or equal to 1 of Si, less than or equal to 1 of Mn, and marginal Fe and unavoidable impurities; wherein, an electromagnetic field with the magnetic strength of 0.21T to 0.30T is applied during the centrifugal casting and solidifying process of the roll barrel working layer. The high carbon, high tungsten and high speed steel material of the invention can produce high carbon, high tungsten and high speed steel composite rollers by adopting an electromagnetic centrifugal casting technique and by replacing V with W, thereby not only eliminating the macroscopic segregation of a cast structure and effectively controlling the even distribution of MC carbide, but also obviously improving the service performance of the high speed steel composite roller.

The invention provides a boron-doped hard alloy and a preparation method thereof. The mass percentage of boron element to bonder is 0.01 percent to 2 percent, preferably 0.05 percent to 1 percent. The preparation method comprises compounding, ball milling, drying, pressing and sintering steps. The boron exists in the form of pure boron powder, TiB2, CrB2, WB, CoB or a combination thereof. During the compounding step, the boron element is mixed thoroughly with WC and Co, and the resulting mixture is subjected to ball mill for 24-72 hours in the presence of alcohol. The strength and hardness of hard alloy are increased while the toughness remains unchanged, or the strength, hardness and toughness all increased.

The invention discloses a special steel for a hardware tool and a preparation method thereof. The steel comprises the following chemical components in percentage by weight: 0.50-0.60% of C, 0.17-0.37% of Si, 0.20-0.50% of Mn, 0.008-0.020% of P, 0.001-0.005% of S, 0.25-0.60% of Cr, 0.20-0.35% of Ni, 0.07-0.25% of Cu, 0.010-0.030% of Ti, and the rest amount of iron and inevitable impurities. The preparation method is performed by a general clean steel process, and comprises the steps of steel smelting, LF furnace refining, continuous casting, casting blank heating, rolling, cooling and reeling. All alloy element components in the steel are designed to properly increase the carbon content and decrease the content of such noble metals as Ni and Cr; the process of smelting and rolling is controlled to obtain the special steel for the hardware tool with high-hardness surface and low-hardness-toughness heart material matrix; and the steel can satisfy the performance needed by the hardware tool and the target of optical economic benefit.

The invention discloses a modified manufacturing process for a high-chromium cast iron composite roll through a forged steel roll neck and equipment. The material comprises, by mass, 3.0%-3.6% of C, 0.60%-1.20% of Si, 0.30%-1.20% of Mn, 3.0%-5.0% of Ni, 1.0%-2.0% of Cr, 0.40%-1.2% of Mo, 0.1%-2% of W, 0.5%-1.0% of Cu, 0%-0.05% of P, 0%-0.03% of S, 0.04%-0.06% of Mg, 0.1%-0.3% of Nb, 0.1%-0.30% of Ti, 0.2%-0.6% of V, 0.05%-0.2% of B, 1.5%-2.5% of Ba, 1%-2% of Ca, 1%-3% of Sb, 0.02%-0.18% of N, 1.0%-2.0% of Y/RE and the balance Fe and inevitable microelements. Yttrium-based rare earth nodulizing and compound inoculating of Ba, Ca and silicon iron are adopted, and modification treatment is conducted by adding Nb, Ti, V, B, and Sb, so that the mechanical property of the roll is improved. The strength of the roll is improved through the forged steel roll neck. Overall in-mold heating and fusion casting are conducted on a core rod through an induction heater. Forming is conducted through a water cooled crystallizer. A composite layer interface can be dynamically controlled. The process is simple, the efficiency is high, power consumption is small, the cost is low, composition segregation is avoided, and the service life of the roll is long.

The invention discloses nickel base alloy powder for overlaying welding of the sealing surface of the intake and outlet valve of automobiles. The nickel base alloy powder comprises the components with the following weight portions of 25-27 percent of Cr, 4-6 percent of Mo, 10-15 percent of Fe, 2-3 percent of Si, 1.5-2 percent of B, 0.65-0.75 percent of C and Ni for the rest. The beneficial effects of the invention are (1) low cost, (2) good technological properties and (3) high hardness. The nickel base alloy powder can take the place of cobalt base alloy powder and has low cost. The price of the nickel base alloy powder is one third of the price of the cobalt base alloy powder. The nickel base alloy powder is especially suitable for plasma overlaying welding technology and vacuum furnace melting technology of the sealing surface of the intake and outlet valve of automobiles and locomotives. Compared with Stellite No. 6 cobalt base alloy powder, the welding layer of the invention processed by the same plasma arc overlaying welding technology has a same volume loss (mm <3>) in wear test. By comparing the hardness of the nickel base alloy powder with the hardness of the Stellite No. 6 cobalt base alloy powder, the two powders have the same hardness HRC which is 43 after the powders are cooled to room temperature. The two powder after being welded have the same hardness under 400-700 centigrade temperature in the furnace, while the nickel base alloy powder has better red-hardness.

The invention relates to a method to produce nitridation metal ceramics that belongs to ceramics material producing field. It adopts optimizing material ingredients, improving nitridation process technology, forming grads structure to improve hardness of the surface and inner tenacity. The ingredients of the metal ceramics is 29<=Tic<=45, 8<=Tin<=12, 28<=Ni<=32, 11<=Mo<=15, 7<=WC<=10, 0.5<=C<=1, 0.5<=NbC<=1. The process to produce is as following steps: first, mixing Tic powder and TiN powder to produce compound including millimicron grade of Ti(C, N) solid solution compound by mechanism alloying. Making the compound mixed with WC, NbC, Mo, Ni, C powder according to the previous ingredients, adding molding dosage for molding; degreasing, sintering and nitridation processing under high temperature and high pressure. The material has high hardness, high bending strength, HV>=2000 and DELTAbb>=1800Mpa. It can be used for cutting tools, drawing die and compression die.

The invention provides high-boron high-chromium low-carbon wear-resisting alloy steel with good red hardness and a manufacturing method thereof. The chemical content of the high-boron high-chromium low-carbon wear-resisting alloy steel includes, by weight, 0.10%-0.5% of C, 12%-26% of Cr, 0.5%-1.2% of Si, 0.5%-1.5% of Mn, 2.5%-3.6% of B, 0.7%-2.4% of Cu, 3.2%-3.9% of Al, 0.8%-1.6% of Ti, 0.02%-0.15% of Ca, 0.03-0.25% of Ce, 0.02%-0.18% of N, 0.05%-0.3% of Nb, 0.12%-0.25% of Mg, 0.04%-0.13% of K, 0.05%-0.12% of Ca, 0.06%-0.15% of Ba, less than 0.03% of S, less than 0.04% of P and the balance Fe and unavoidable impurity elements. After steel scrap and ferrochromium are melted in an electric furnace, a copper plate, silicon iron and ferromanganese are added to the electric furnace, after content is qualified through pre-furnace adjustment, the temperature of a melt rises to 1560-1620 DEG C, calcium-silicon alloy and deoxidation aluminum are added, ferrotitanium, ferroboron and metal aluminum are sequentially added and poured out of the furnace after being melted, granular rare earth magnesium alloy with the diameter of less than 12mm and a composite inoculant composed of metal cerium, Si3N4, VN, Nb and K are placed at the bottom of a steel ladle after being roasted, metaphoric inoculation processing is carried out on smelt liquid steel in a in-ladle pouring mode, the liquid steel pouring temperature ranges from 1400 DEG C to 1450 DEG C, and a casting piece undergoes air cooling for 2-4 hours at the temperature of 920-1150 DEG C.

The invention provides high alloy cutting tool steel for wood-working machine rotary cutter blades and a hot processing process of the high alloy cutting tool steel. The cutting tool steel comprises the following components by weight percent: 0.58-0.69 percent of carbon, 0.75-0.95 percent of silicon, 0.35-0.55 percent of manganese, 7.20-8.20 percent of chromium, 0.2-0.40 percent of vanadium, 0.95-1.45 percent of tungsten, 1.55-1.90 percent of molybdenum, not greater than 0.030 percent of sulfur, not greater than 0.030 percent of phosphorus and the rest of iron. The alloy cutting tool steel has the advantages of high strength and toughness, high abrasion resistance, high hardness and good red hardness and can meet the requirements of slicing and rotatably cutting veneers. The cutting tool steel and other plate materials are combined in a high strength to perform hot processing; the performances of the cutting tool steel are played to the maximum through the processes of hot molecules infiltration, hot rolling pressing and secondary quenching; the hardness, the abrasive resistance and the strength and toughness of the cutting tool steel are further improved.