900 results about "Carburizing" patented technology

A multi-purpose, multi-oxy-fuel High Temperature Power Burner/Injector/Oxygen Lance, Mechanical System Apparatus Device, for steelmaking from recycled scrap and/or virgin ferrous charge, which can be employed in multi-oxy-fuel (natural gas; pulverized carbonaceous matter; heavy oil), especially by Oxygen Combusted mixture of Natural Gas/Pulverized Carbonaceous Matter in High Temperature Power Burner Mode, for efficient and rapid melting of solid ferrous charge (cold or preheated) in a special steelmaking Metallurgical Furnace or Open Hearth Furnace, Tandem Furnace, BOF, EAF, as its augmenting or only source of thermal energy; more than one Device in Oxygen-Natural Gas/Pulverized Carbonaceous Matter Power Burner Mode, can be employed as the only source of thermal energy in a modified, originally Electric Arc Furnace, as total replacement of Graphite Electrodes and Electric Arc System, the replacement being noticeably more primary energy efficient than the thermal energy provided by Graphite Electrode/Arc System; it also can be employed in an Solid Particles Injector Mode, for injecting of adequately granulated carbonaceous materials or lime into the molten steel for its carburizing or for foamy slag control; further it can be employed in a natural gas shrouded, pulsating oxygen stream, for vertically to the charge oriented soft blow supersonic Oxygen Injection Lance Mode, for decarburization of the molten metal contained in the hearth of the metallurgical furnace and foamy slag control; in one of the embodiments-generally arcuate-pivotally mounted, liquid media cooled composite body, is pivoted into and out of a furnace vessel through a small opening in the shell wall for auto-regulated constant optimal positioning of the Composite Body Tip against solid or molten charge, in each and all multi-purpose modes; furthermore, when inserted into the furnace vessel, the arcuate composite body can be rotated about its longitudinal axis for directing the oxy-fuel high temperature flame towards unmolten charge in the furnace; in an other-generally linear-embodiment, the liquid cooled composite body is attached to the mast type carrier allowing vertical movement of the composite body which enters the furnace vessel through a small opening in the furnace roof; the bimetallic, liquid cooled special tip assembly of both-arcuate and linear embodiments-of the composite body includes easy replaceable, independent, multi-opening nozzles, mounted in a protective, retracted position inside of the liquid cooled special tip assembly.

The invention discloses a manufacturing method of an integral herringbone gear shaft, which comprises the following steps that: material preparation: a center hole is drilled on one end of a work piece; primary machining; primary detection; heat treatment; secondary machining; secondary detection; rough milling; chamfering at the gear end; coating anti-carburizing layers on both ends of the herringbone gear shaft so that the depth of a carburized layer is 3.55 to 3.95mm, and quenching so as to enable the hardness of a gear part to reach HRC58 to 62, and to enable the hardness of the heart to reach HRC28 to 33; carrying out shoot peening on a gear surface; tertiary machining; gear shaping; external grinding; fine milling; and inspection. The manufacturing method of the integral herringbone gear shaft has the advantages of improving the bending strength of the gear root, reducing the manufacturing cost and improving the manufacturing precision.

The invention relates to a high-toughness carburized bearing steel with ultra-long contact fatigue life and a preparation method thereof, belonging to the technical field of alloy steel. The steel comprises the following chemical components in percentage by weight: 0.16-0.24% of C, at most 0.10% of Si, at most 0.10% of Mn, 0.30-1.50% of Cr, 1.5-4.5% of Ni, 0.30-1.50% of Mo, 0.02-0.10% of Nb, 0.3-0.9% of V, and the balance of Fe and inevitable impurities, wherein [N]+[O]+[H]+P+S<=0.0080%, and Ti<=0.0030%. The invention particularly relates to a high-toughness carburized bearing steel which has the advantages of high shock resistance load, stable dimension and ultra-long contact fatigue life in the serve process. Compared with the prior art, the invention has the advantages of high surface hardness, high core toughness, high dimensional stability, high bending fatigue strength limit and ultra-long contact fatigue life.

A process for laser powder-melting onto the surfaces of the teeth parts that are of heavily loaded cemented steel to be repaired is disclosed herewith. The powder of grains = (-140-+260 mesh) comprises (mass%): C 0.80-1.10, Mn 7.50-9.00, Cr 0.90-1.30, Mo 0.20-0.35, B 2.00-3.50, Si 2.50-3.50, and balanced with Fe with impurities of P not more than 0.06 and S not more than 0.04. Laser power density is equal to 1.0 X 108W-109W/m2 per unit of time. The said powder has good re-melting property, self-enhancing and fatigue-resistance performances, so that it can be used to repair worn gears.

The invention relates to a protective coating for the surface of a steel workpiece, which comprises the following components: graphite, sodium silicate and a surface penetrant, wherein the volume ratio of the graphite to the sodium silicate is 1: 3-7; and the surface penetrant accounts for 0.05 to 0.15 percent of the total volume in the components. The coating has the advantages that the coating not only avoids disadvantages caused by usual methods such as adding alloy, performing surface high-frequency quenching, forming carburizing atmosphere and the like, prevents the surface of the steel workpiece from high-temperature oxidation decarbonization, but also improves the hardness of the surface of the steel workpiece (matrix) to realize the improvement of the wear resistance thereof, and solves the existing problems of high production cost, low production efficiency, long production period, large energy consumption and environmental pollution.

The invention relates the low-alloy high-tensile structural steel and preparing method. The components are as follows: C:0.05%-0.60%, Si: 0.05%-0.70%, Mn: 0.5%-2.5%, P: <= 0.04%, S: <=0.04%, Cr: 0-0.70%, Ni: 0-0.70%, molybdenum: 0-0.60%, Cu: 0-0.20%, vanadium: 0.01%-0.30%, Al 0-0.1%, niobium: 0.001%-0.10%, N: 0.004%-0.02%, and the left is Fe. The method comprises the following steps: using revolving furnace to smelt, and using LF furnace to refine. The yield strength as is above 460Mpa, the dynamic ductility Akv is above 27J at low temperature (-40Deg.C), endurance life is above 2 million times, and the finished steel can be used for train brake beam, engineering machinery and hydraulic support without heat treatment. After quenching and high tempering modified heat treatment, the strength for extension of the steel is above 750Mpa, the dynamic ductility Akv is above 150J at low temperature (-40Deg.C). After carbonization, the steel can be used for abrasion-proof driving mechanism elements and parts.

The invention provides a technology treatment method of machining deformation of a long and thin hole shaft type thin-wall part, and aims at providing a technology treatment method of the machining deformation, which is simple in flow, and high in machining precision and yield. The method adopts the following technical scheme that the method comprises the steps that the long and thin hole shaft type thin-wall part after mechanical rough machining and carburizing treatment is subjected to quenching heat treatment, subzero treatment and low temperature tempering treatment. During the quenching heat treatment, the quenching cooling time is 8-11S/mm; when a surface temperature of the part falls to 30-50 DEG C, the part is lifted up from oil; the surface temperature of the part rebounds in air after some time; and when the part is cooled to 30-50 DEG C again, residual oil is rinsed cleanly by hot water greater than or equal to 60 DEG C. During the subzero treatment, the part is transferred to a -70 DEG C to -80 DEG C refrigerator box to be refrigerated for 2-2.5h within 1h after quenching, and then subjected to air cooling for 60-90min till the part reaches a room temperature. During the low temperature tempering treatment, the part is subjected to heat preservation for 3-4h at 160-180 DEG C and the air cooling. The method solves the problem of the machining deformation of the long and thin hole shaft type thin-wall part due to heat treatment stress, grinding stress and the like, and the yield reaches 100%.

A stainless steel pipe includes a base metal containing 20-35 mass % of Cr, and a Cr-depleted zone is formed in the surface region of the pipe. The Cr concentration in the Cr-depleted zone is at least 10%, and the thickness of the Cr-depleted zone is at most 20 micrometers. A Cr-based oxide scale layer having a Cr content of at least 50% and a thickness of 0.1-15 micrometers may be provided on the outer side of the Cr-depleted zone. An Si-based oxide scale layer with an Si content of at least 50% may be provided between the Cr-based oxide scale layer and the Cr-depleted zone. The pipe is particularly suitable for use in petroleum refineries or petrochemical plants, such as for use as a pipe of a cracking furnace of an ethylene plant.

The invention discloses a method for manufacturing nanometer tungsten/cobalt carbide composite powder. The method is characterized by comprising technological steps of firstly, dissolving, by mass, 55-92% of water-soluble tungsten salt, 3-40% of water-soluble cobalt salt, 3-6% of water-soluble carburizing and nodulizing agents and 0.1-2% of water-soluble composite grain growth inhibitors into water with the mass 3-5 times that of a mixture of the water-soluble tungsten salt, the water-soluble cobalt salt, the water-soluble carburizing and nodulizing agents and the water-soluble composite grain growth inhibitors to prepare mixed aqueous solution; secondly, adding carbon nano-tubes (CNT) accounting for 1-10% of the total mass of the aqueous solution into the mixed aqueous solution obtained in the first step and enabling the carbon nano-tubes to be uniformly mixed in the mixed aqueous solution; thirdly, performing quick low-temperature spray drying for mixed aqueous solution obtained in the second step to obtain precursor powder of ultrafine tungsten and cobalt composite salt; and fourthly, performing reduction synthesis and carbon conditioning at the temperature ranging from 900 DEG C to 1000 DEG C for the precursor powder obtained in the third step to prepare tungsten/cobalt carbide composite powder materials with nanostructures.

The invention relates to steel for an Nb-Ti composite microalloyed high-temperature vacuum carburizing heavy-duty gear. The steel is prepared from the following components in percentage by mass: 0.15-0.23 percent of C, 0.10-0.40 percent of Si, 0.45-0.90 percent of Mn, 1.50-1.80 percent of Cr, 1.40-1.70 percent of Ni, 0.15-0.55 percent of Mo, 0.02-0.08 percent of Nb, 0.015-0.08 percent of Ti, smaller than or equal to 0.020 percent of P, smaller than or equal to 0.020 percent of S and the balance of Fe and inevitable impurities. For the steel provided by the invention, by adopting a composite microalloying manner, adding Nb and Ti microalloy elements and controlling the contents of the Nb and Ti microalloy elements, a precipitated phase is utilized to pin a crystal boundary to inhibit coarsening and growth of austenite grains in the high-temperature vacuum carburizing process, increase of the steel carburizing temperature of the heavy-duty gear is realized, the gear carburizing heat treatment process time is effectively shortened, the energy consumption is greatly lowered, and the production cost of the gear is saved.

The invention relates to a technology for controlling hardness distribution of a material for a 23CrNi3Mo drill tool. After carburization, mild hardness gradient distribution of the drill tool from surface to center is realized, namely, micro hardness from the surface to the center tissue of the drill tool drops mildly, so that after carburization, the drill tool forms a complex phase tissue which has high surface hardness, high center toughness and a transition layer with certain width, the drill tool is good in toughness and is prolonged in service life. The technology comprises the following steps of quenching the carburized drill tool at 880DEG C+/-10 DEG C; preserving heat for 45 minutes; after thermal insulation, cooling by two sections, wherein the cooling rate is more than or equal to 5 DEG C per second in temperature range of 880-450; cooling to room temperature along with a furnace below 450 DEG C; tempering at 220 DEG C and preserving heat for 120 minutes; and carrying out air cooling to reach room temperature after thermal insulation.

A method for carburizing workpieces made of steel, particularly workpieces having outer and inner surfaces, the workpiece being held at a temperature in the range of 850 to 1050° C. in an atmosphere containing a gaseous hydrocarbon. At least two different gaseous hydrocarbons are used and/or the workpiece is alternatingly held in the atmosphere containing the gaseous hydrocarbon during a carburizing pulse and in an atmosphere free of hydrocarbon during a diffusion phase. Also described is a use of the method.

The invention belongs to the technical field of electric arc furnace steelmaking and particularly relates to a full-steel-scrap electric arc furnace cleanness rapid smelting method which is applicable to the 30-300t full-steel-scrap electric arc furnace smelting process. According to the full-steel-scrap electric arc furnace smelting process, spray guns buried in refractory materials on the side faces of the furnace bottom of an electric arc furnace are used for blowing different types of media at different smelting stages; at the stage of recarburization and melting acceleration, melting-down of a molten pool is accelerated through carburization, and the carbon content of the molten pool is increased. At the stage of high-efficiency dephosphorization and deep denitrification, molten pool reaction is intensified to conduct high-efficiency dephosphorization and deep denitrification. Accordingly, the smelting rhythm of the full-steel-scrap electric arc furnace is accelerated, the dephosphorization and denitrification effects are improved, the cleanness of molten steel is improved, and full-steel-scrap electric arc furnace cleanness rapid smelting is realized.

The centerpiece for universal coupling is made with high quality low carbon alloy structural steel 20CrMnTi, and through blanking, precise die forging, normalizing, machining, surface carburizing, surface hardening, low temperature tempering and finish grinding. It his excellent mechanical performance, including high toughness, high strength and high wear resistance, and can ensure smooth running, high safety, high reliability and long service life of the coupling.

The invention discloses a carburizing bearing steel, which comprises the following chemical elements in percentage by mass: 0.10-0.16% of carbon, 0.40-0.90% of manganese, 0.15-0.40% of silicon, 1.30-1.80% of chromium, 3.10-3.80% of nickel, 0.02-0.09% of molybdenum, 0.015-0.040% of aluminum and 0.0040-0.0070% of nitrogen, less than or equal to 0.0010% of oxygen, less than or equal to 0.020% of phosphorus, 0.005-0.020% of sulfur, less than or equal to 0.0020% of titanium, less than or equal to 0.15% of copper, less than or equal to 0.025% of tin, less than or equal to 0.015% of antimony, less than or equal to 0.030% of arsenic, and the balance of Fe and inevitable impurities, wherein the ratio of aluminum/nitrogen is more than or equal to 3. The carburizing bearing steel disclosed by the invention is easy for carburizing surface treatment, and has excellent strength and toughness.

Low carbon carburizing (surface hardening) and higher carbon through hardening steels primarily containing molybdenum, vanadium and nickel and, to a lesser amount, chromium used for rolling contact bearings, gears and other similar applications where high hardness at elevated temperatures is required. The alloy steel includes, in % by weight: 0.05% to 1.25% C; up to 1.25% Cr; 0.40% to 4% Mn; up to 4.0% Mo; up to 2.0% V; 1.0% to 3.0% Ni; 4% to 8% (Mo+V+Ni+Cr); less than 0.20% Si; and balance Fe plus incidental additions and impurities. The method for providing a steel having improved hardness at elevated temperatures includes the steps of: (a) providing an alloy including, in % by weight: less than 1.25% Cr, 0.4% to 4% Mn, up to 4% Mo, up to 2% V, 1 to 3% Ni, 4% to 8% (Mo+V+Ni+Cr), less than 0.2% Si, a C content selected from one of 0.05% to 0.40% C defining a carburizing steel or greater than 0.40% to 1.25% C defining a through hardening steel, and the balance Fe plus incidental additions and impurities; (b) performing a step selected from the group consisting of (i) subjecting the carburizing steel to carburizing and quenching to provide a quenched carburized steel, or (ii) subjecting the high carbon steel to hot working to provide a wrought high carbon steel; (c) preheating the quenched carburized steel or wrought high carbon steel and then austenitizing said steel to provide an austenitized steel; (d)quenching the austenitized steel to provide quenched austenitized steel; and (e) tempering the quenched austenitized steel followed by air cooling.

The invention discloses a method for processing a rectangular-tooth spline sleeve using 42CrMoE high-quality alloy steel as a material, belonging to the technical field of thermal treatment. The method comprises the steps of: free forging of a blank, normalizing treatment, rough turning, hardening and tempering thermal treatment, finish turning, spline drawing, drilling, burr gripping, carburization treatment, surface deposition treatment, phosphorylation treatment, electroplating, drying and detection. In the invention, due to the new material and new technology, the wear resistance of the produced rectangular-tooth spline sleeve is greatly enhanced, the phenomenon of crack of the rectangular-tooth spline sleeve is avoided, the surface is smooth, the friction is low, the heat dissipation is good, and the service life is prolonged, thus the processing technology is widely applied.

The invention relates to a surface metallurgy process of cobalt containing super-hard high-speed steel, which pertains to the surface metallurgical field. The invention is characterized in that: first, a double-layer glow discharging ion metallic cementation technique is used for filtering an alloying element on the surface of Fe-based material with lower cost so as to form a surface alloying layer; then, a carburizing treatment is carried out to form a surface high-speed steel alloying layer; thereafter, a thermal treatment is carried out to lead the surface high-speed steel alloying layer to have the excellent properties of the super-hard high-speed steel. The hardening characteristics of the super-hard high-speed steel is that fine and dispersed alloy carbide and intermetallic compound are precipitated to generate hardening, the surface hardness of the filtered workpiece reaches at 1000-1150HV after quenching and tempering treatment. The invention has the advantages that: since coarse primary carbide is not formed during the crystallizing process, formidable inhomogeneous carbide in the traditional production of smelting, forging-rolling high-speed steel is solved. Fine and dispersed carbide on the surface metallurgical high-speed greatly improves the hardening effect, saves a great deal of alloying elements, reduces the cost and is capable of being widely used for manufacturing cutting tools of various machine tools.

The process includes heating of steel alloy parts in the presence of hydrogen prior to introduction of, for example, carburizing gas, preferably acetylene, in the presence of a diluent carrier gas. The process uses a continuous cycle involving only one carburizing (boost) step and one diffusion step, and high velocity gas quenching. The process is advantageously carried out in a unique, versatile vacuum furnace (also having high internal pressure capability) that provides very high velocity, continuous flow gas quenching, and a furnace design, including a long, low profile work zone configuration and quench gas recirculation equipment and flow pattern that facilitates high velocity gas flow. The entire process is accomplished in a single self-contained chamber of the furnace.

The invention discloses a method for manufacturing tungsten/cobalt carbide composite powder with a nanostructure. The method includes steps of firstly, dissolving, by mass, 55-92% of water-soluble tungsten salt, 3-40% of water-soluble cobalt salt, 3-6% of water-soluble carburizing and nodulizing agents and 0.1-2% of water-soluble composite grain growth inhibitors into water with the mass 3-5 times that of a mixture of the water-soluble tungsten salt, the water-soluble cobalt salt, the water-soluble carburizing and nodulizing agents and the water-soluble composite grain growth inhibitors to prepare mixed aqueous solution; secondly, quickly crystallizing the mixed aqueous solution obtained in the first step; thirdly, pre-treating crystalline, which is obtained in the second step, at the pretreatment temperature ranging from 500 DEG C to 700 DEG C to obtain nodular powder; and fourthly, performing reduction synthesis and carbon conditioning for powder materials, which are obtained in the third step, at the temperature ranging from 900 DEG C to 1000 DEG C to manufacture tungsten/cobalt carbide composite powder materials with nanostructures. The method has the advantages that a process is simple, and the hard alloy powder materials with the nanostructures can be produced in an industrialized manner.

The invention discloses a clutch gear quenching process. The process comprises the following steps: incoming materials inspecting, charging, primary cleaning, subsequent cleaning, annealing, testing,shot blasting, rust proofing and the like, wherein between the steps of primary cleaning and subsequent cleaning, carburizing and nitrogen quenching processes are performed at 85-925 DEG C, CP is 0.75%-1.15 %; the oil temperature in cleaning processes is 110-120 DEG C, the desired time between the primary cleaning process to the primary cleaning process is 410-440min; the desired environment for annealing is as follows: the flow of methanol is 2.8-3L/H, the flow of propane is 14-16L/min, the flow of ammonia is 2.8-3L/min, the flow of equilibrium air is 14-16L/min, the flow of reference air atthe ammonia probe is 80-160mil/min and the oil mixing speed is 30hz.