35results about How to "Increase carburizing speed" patented technology

The invention provides a heat treatment method of a spiral bevel gear of a cargo truck on double-row rare earth carburization equipment, and relates to a carburization heat treatment technological process of the spiral bevel gear of the cargo truck. The invention solves the problems that energy consumption of carburization heat treatment is high, production cost of a product is high and carburization quenching and gear thermal distortion still exist in a carburization process. The method provided by the invention comprises the following steps of: taking a preheating zone as a strong leakage region 1 and taking a carburizing region as a strong leakage region 2, namely taking a region II and a region III as a carburizing speed main control region and taking a region IV and a region V as a metallographic structure main control region, carrying out temperature control in the regions I, II, III, IV and V, carrying out carbon potential control in the regions II, III, IV and V, and inputtingcarburizing medium propane gas, rare earth methanol penetrating agent, nitrogen, methanol and air into a furnace, thus the heat treatment method is realized. The metallographic structure and surface hardness of the spiral bevel gear subjected to the heat treatment method provided by the invention are all optimized, and heat treatment quality of the spiral bevel gear is improved; meanwhile, capacity is improved by 23%, heat treatment production cost is reduced by 18.9%, and pollution of exhaust emission to the environment is reduced.

The invention relates to a control system of the carbon intensity distribution of a low-pressure carburized layer and a control method thereof, belonging to the technical field of metal heat treatment. The control system comprises a low-pressure carburizing furnace, a controller, a pressure sensor, a thermoelectric couple, a nitrogen regulating valve, a nitrogen input pipe, a carburizing gas regulating valve, a carburizing gas input pipe, a vacuum system and a gas suction pipe. The invention simulates automatic optimized low-pressure pulse process parameters by using carburized layer concentration distribution values and realizes the control functions; the carburizing gas regulating valve executes on/off action according to an order of the controller to control carburizing section time and diffusing section time, therefore the accurate control of the intensity distribution of the carburized layer is realized; and in addition, the invention can keep high carburizing speed and prevent the tolerance of surface carbides, accurately controls the surface carbon intensity and the depth and the intensity distribution of the carburized layer, reduces the accumulated carbon black inside the low-pressure carburizing furnace, is free from depending on a gas component sensor and has the advantages of configuration simplification, easy implementation, high reliability and easy maintenance.

This invention relates to gas carburizing the toothed-wheel of heavy duty automobile. It is characterized that this invention utilizes carbon-potential pulsation type gas carburizing, so it overcomes the prior art short comings that carbonization is proceeded under high carbon-potential and diffusion is finished under low carbon-potential. After quenching, the working-pieces have excellent carburized layer concentration gradient distribution, hardness gradient distribution and carburized layer histogram. This inventive method makes parts thus carburized have long service life under complex condition, after the parts are carburized and have gentle hardness gradient.

The invention discloses a cooling and accelerating vacuum carburizing method, and belongs to the field of heat treatment and surface engineering. The method aims to solve the problems of high carburizing temperature, long carburizing period and the like in an existing vacuum carburizing technology. The cooling and accelerating vacuum carburizing treatment method comprises the following steps of firstly, sequentially carrying out surface polishing and cleaning treatment on a substrate; secondly, mixing rare earth oxide powder with hard ceramic powder to obtain mixed powder, arranging the substrate below a gun head of supersonic particle bombardment equipment, performing supersonic particle bombardment treatment on the mixed powder, and controlling the spraying speed to be 300-1200m/s to obtain a substrate with a nanometer-rare earth modified layer; third, putting the substrate with the nanometer-rare earth modified layer into a vacuum carburizing furnace, vacuumizing in the furnace, andheating to a carburizing temperature to carry out vacuum carburizing treatment. Compared with common vacuum carburization, the composite strengthening technology adopted by the invention can reduce the carburization temperature, improve the vacuum carburization efficiency, shorten the carburization period and improve the surface hardness of a carburized layer.

The invention discloses a catalytic permeation method for increasing austenite stainless steel low-temperature gas carburizing speed, and belongs to the technical field of chemical heat treatment. The gas carburizing treatment is performed for austenite stainless steel by a mixed carburizing agent at a temperature of 450-470 DEG C; the mixed carburizing agent consists of a gas-phase carburizing agent and a liquid-phase rare earth catalytic permeation agent; the gas-phase carburizing agent consists of CO, H2 and N2; the liquid-phase rare earth catalytic permeation phase consists of rare earth chloride and methanol solution; gas generated by gasifying solvent methanol of the gas-phase carburizing agent and the liquid-phase rare earth catalytic permeation agent in a carburizing furnace is formed to carburizing furnace gas; the mass fraction of the rare earth element in the liquid-phase rare earth catalytic permeation agent is 0.8-1.5% of mass fraction of the carburizing furnace gas; the treatment is kept by 24-28 h; the temperature is cooled below 150 DEG C in an original atmosphere furnace; and a corrosion-resistance strengthened carburizing layer with a surface hardness of 850-1200 HV is obtained on the austenite stainless steel. The catalytic permeation method improves the corrosion-resistance strengthened treatment efficiency of the austenite stainless steel, and reduces the production cost.

The invention relates to a sub-temperature carburizing heat treatment method for reducing heat treatment deformation of a thin-wall gear. The method comprises the following steps of S1, pre-sub-temperature normalizing; S2, slow speed shot blasting; S3, sub-temperature carburization, specifically, gradient heating is adopted to a sub-temperature carburizing temperature, a two-stage carburizing method is adopted in the sub-temperature carburizing process, the first stage is a strong carburizing stage, and the second stage is a diffusion stage; S4, gradient slow cooling quenching, specifically, firstly, gradient slow cooling is carried out on a carburized thin-wall gear forging to 840-860 DEG C, heat preservation is carried out for about 1h, then the slow cooling is continuously carried out to 815-825 DEG C, the heat preservation is carried out for about 1h, the carbon potential in the furnace is controlled to be 0.5-0.05%, and then quenching is carried out in a polyvinyl alcohol solution; and S5, low-temperature tempering. According to the method, the deformation degree of a gear workpiece can be greatly reduced, the production qualification rate can be obviously improved, meanwhile,crystal grains can be effectively refined, the hardness and strength of a gear can be improved, the service life of the gear can be obviously prolonged, and in addition, the refined crystal grains can obviously improve the carburizing speed, reduce the process time and reduce the energy consumption.

The invention provides a vehicle transmission gear and a manufacturing method thereof. The manufacturing method comprises the steps of blank forming, preheating treatment, turning machining, final heat treatment and finish machining, wherein the final heat treatment step comprises multiple times of carburization, carbonitriding, quenching, tempering and the like. The vehicle transmission gear manufactured through the manufacturing method has the excellent comprehensive performance.

The invention discloses high-speed bearing steel and a preparation method thereof. The high-speed bearing steel comprises the following components in percentages by weight: 0.4-0.45% of carbon, 0.9-1% of silicon, 0.95-1.05% of manganese, less than 0.01% of phosphorus, less than 0.005% of sulfur, 1.4-1.6% of chromium, 0.4-0.5% of nickel, 0.85-0.95% of molybdenum, less than 0.1% of copper, 0.085-0.1% of aluminum, 0.08-0.15% of vanadium, 0.08-0.15% of niobium and the balance iron. The oxygen content of the high-speed bearing steel is lower than 15PPM. The hydrogen content of the high-speed bearing steel is lower than 2PPM. The high-speed bearing steel disclosed by the invention is low in production cost and meets various mechanical performance requirements.

The invention discloses a hot working method of a high-performance small-distortion carburized outer ring, relates to the technical field of hot working methods, and solves the technical problems of complex manufacturing process, non-uniform carburized layer depth and poor quality consistency of the existing outer ring, and is suitable for forging and heat treatment of the outer ring made of 17Cr2Ni2MoVNb steel, the diameter of the outer ring is 150-200 mm, and the wall thickness of the outer ring is 8-10 mm. The hot working method comprises the following steps of constructing a true stress-strain curve and a hot working diagram, forging, normalizing and tempering at a high temperature, roughly machining, thermal refining, roughly machining a tooth shape and the like, performing gas/liquid composite carburizing and tempering at a high temperature, quenching and tempering at a low temperature. According to the hot working method, the ovality of the carburized and quenched outer ring is controlled to be less than or equal to 0.15 mm, the grain size is greater than or equal to 8.5 grades, and the rotating bending fatigue strength of a furnace sample is greater than or equal to 1000 MPa; and the part has high performance, meanwhile, only small heat treatment deformation exists, and good industrial application value is achieved.

The invention provides an enriched energizer for low-temperature gas carburization of a large-sized high-speed and heavy-duty thin-walled gear and belongs to the technical field of chemical heat treatment. The energizer comprises the following components in percent by weight: 5-8% of rare earth, 10-20% of carbon tetrachloride, 1-5% of lithium zirconate and the balance heterogeneous alcohols, wherein the rare earth is composed of 90% of lanthanum oxide and 10% of cerium oxide. By taking the rare earth, carbon tetrachloride, lithium zirconate and heterogeneous alcohols as raw materials which areweighed in proportion and are uniformly mixed to form the energizer, the energizer is used for gas carburization of the large-sized high-speed and heavy-duty thin-walled gear. The energizer decreasesthe carburization temperature, shortens the carburization time and reduces deformation and further improves the surface hardness, wear resistance and fatigue performance, so that the service life ofthe gear is prolonged.

The Invention relates to an atmospheric-pressure acetylene carburizing furnace, comprises a reaction chamber, an acetylene intake duct, an exhaust gas duct, a control and metering apparatus, an exhaust gas measurement apparatus, and a computer controller. The computer controller calculates a total amount of carbon in the furnace and an enrichment rate of a workpiece, and adjusts an acetylene intake volume according to the calculation result until process requirements are met. The Invention realizes carburizing with acetylene under atmospheric pressure and reduces the usage costs while improving the equipment efficiency.