286 results about "Carbon potential" patented technology

The invention relates to a medium-deep-layer carburization or carbonitriding thermal processing technology for bearings or clutch parts. In the invention, the carburization or carbonitriding is carried on parts by utilizing a continuous production line of a carrier roller type mesh belt furnace with a controllable atmosphere, and the technology comprises the following steps in sequence: strong permeation, diffusion, quenching, cleaning, low-temperature tempering, discharging and air cooling. In the invention, the continuous production line of the carrier roller type mesh belt furnace with the controllable atmosphere is used for carrying out the medium-deep-layer carburization or carbonitriding, thus continuous production is realized, the production efficiency is improved, the productivity is increased, frequent opening and closing actions of a gap furnace can be reduced, non-oxidization treatment is realized, and the labor intensity is reduced; and in addition, carbon potentials in all areas of the mesh belt furnace are respectively controlled so as to guarantee the quality stability.

The invention provides a carburizing and quenching method for a large heavy-duty gear; the method includes a segmented temperature-rising temperature-equalizing step, a carbon potential gradual-reduction carburization step, a segmented temperature-lowering temperature-equalizing step, a stepped quenching step, and a low-temperature tempering step. The carburizing and quenching method for the large heavy-duty gear not only can shorten the heat treatment period, improve production efficiency and save energy consumption, but also can effectively control heat treatment deformation of the gear, optimize a metallographic structure of the gear surface and improve comprehensive mechanical properties of the gear.

The invention discloses a thermal treatment method for an internal spline gear with small modulus. The method has a principle similar to a press quenching and is characterized in that: a core rod with the size consistent to the size of a spline internal hole is adopted, as the size of the spline internal hole is basically consistent to the size of the core rod, the core rod is inserted into the spline internal hole when a spline is heated to the quenching temperature and is taken out of a furnace for quenching; due to the principle of expansion with heat and contraction with cold, the spline and the core rod are tightly pressed together after oil feeding; due to the limitation of the size and the shape of the core rod, the deformation is limited in a defined range. According to the thermal treatment method, a controllable atmosphere heat treatment furnace is adopted for carburization; and through controlling furnace temperature, insulation time and carbon potential and selecting a proper core rod for quenching thermal treatment, the deformation requirement after carburization and quenching of the spline internal hole can be met. Meanwhile, the grinding step is omitted, the use requirements of a carburized layer and the hardness of the core part of a part can be ensured.

A cemented quenching heat treatment method of automobile engine gears comprises a step of carrying out cemented quenching treatment on the forged, pre-heated, machined and hobbed gears. Cemented quenching treatment comprises the following steps that (a) the gears are arranged in a tooling set with a middle round rod in a stacked manner, a cover plate is configured above the gears, and a gear string is formed; (b) multiple gear strings are fed into an Aichelin5 / 3 type multi-purpose furnace to be carburized and quenched, wherein the carburizing and quenching step specifically comprises the stages that firstly, the gear strings are heated to 800 DEG C, then, heat preservation is carried out on the gear strings for 0.2 hour, the carbon potential is 0.3 percent; then, the gear strings are heated to 900 DEG C to be carburized, the strong carburization potential is 1.1 percent, the strong carburization time is 130 minutes; the gear strings are subjected to diffusion, the diffusion carbon potential is 0.7 percent, and the diffusion time is 90 minutes; the gear strings are cooled along with the furnace temperature, and are cooled to 810 DEG C, heat preservation is carried out on the gear strings for 0.2 hour, the carbon potential is 0.7 percent; the gear strings are fed into a front chamber to be quenched, the quenching oil temperature is 50 DEG C, the quenching time is 20 minutes, rapid stirring reaches 1200r / min and the time is five minutes, slow stirring reaches 1100r / min and the time is 15 minutes; and the quenched gear strings are taken out of the furnace; (c) the quenched gear strings taken out of the furnace are cleaned, and low-temperature tempering is further carried out.

The invention discloses a production method of spherical iron-carbon micro-electrolysis filler. With 75-80wt% of powered iron, 12-15wt% of pulverized coal, 1-2wt% of bentonite, 5-8wt% of borax and 0.1-1wt% of metal catalyst as raw materials, the method comprises the following steps: mixing the powered iron and pulverized coal with the bentonite, borax and metal catalyst and stirring into a mixture; feeding the mixture into a pelletizing machine and spraying in water accounting for 9-10% of the mixture by weight; pelletizing a spherical green body, drying and putting into a high temperature resistant steel bowl; putting the steel bowl into a kiln; heating to 1,000-1,080 DEG C and preserving heat for 2-4 hours; and cooling and discharging. In the invention, the spherical iron-carbon micro-electrolysis filler has a honeycomb-shaped hole structure inside, and the hardening and passivation of the filler can be effectively prevented; wastewater can be quickly absorbed through capillary pores inside, thereby improving the reaction efficiency; and micro-current is formed by use of the iron-carbon potential difference generated by micro-electrolysis to stimulate the generation of nascent hydrogen and oxygen in wastewater, so that strong redox reaction of the wastewater occurs, the hardly-degradable matters are converted into easily-degradable matters, and thus the aim of sewage treatment is achieved.

The invention discloses a production method for a dedicated steel ball for a bearing of a high-speed high-precision numerical control machine tool. The method comprises the following steps of steel ball cold heading, namely machining blank by sleeve cutting, shaping, cold heading multi-station and high-speed cold heading ways; rough machining by adopting a macrocyclic light bulb technology; performing controllable atmosphere quenching, cold treatment and tapering treatment by adopting a continuous drum furnace, automatically controlling carbon potential; surface strengthening by adopting a frequency conversion speed adjusting multi-beating-plate structure; hard grinding by adopting a ceramic sand wheel to perform macrocyclic process to machine; after primary grinding, adopting double-roller sorting; after fine grinding, performing photoelectric eddy current test; performing ultra-fine grinding machining after aging treatment; and performing photoelectric detection after ultra-fine grinding. The diameter variation of the steel ball which is machined and produced by the method provided by the invention is less than 0.07 micron, the roundness is less than 0.05 micron, the spherical error is less than 0.05 micron, the surface roughness Ra is less than 0.07 micron, the variation of the diameter of the ball lot is less than 0.09 micron, and the bearing dmn value of the steel ball after being sleeved is more than 2.5*10<6> mm*r / min.

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 method for measuring carbon emission quantities during power consumption by active power distribution network users and based on carbon emission flow, and belongs to the technical field of low-carbon electric power and electric power system operation measurement. The method comprises the following steps: a topological structure, system parameters and running state data of an active power distribution network are input from a power grid database to form a basic database; data are selected from the basic database to construct a computing matrix and a vector of the carbon emission flow of the active power distribution network; zero flux nodes which affect the solution feasibility of the carbon emission flow in the active power distribution network are judged and removed; the constructed computing matrix and the constructed vector are used for solving the node carbon potential of all non-power-supply nodes in all time periods in the active power distribution network; and the carbon emission quantities during the power consumption by all users at all the nodes in all the time periods are calculated according to the obtained carbon potential of all the user nodes in the active power distribution network, and therefore the measurement of the carbon emission quantities during the power consumption by the users in a single time period and multiple periods is finished. According to the method, the carbon emission flow theory is applied to the active power distribution network, and therefore the carbon emission quantities during the power consumption by the users can be observed and measured.

The invention discloses an automobile gearbox gear carburizing and quenching heat treatment method. The method comprises the following steps: 1, carburizing: placing a gear in a heating furnace, and rising temperature of the heating furnace from room temperature to 900+ / -5DEG C for carburizing for 3-4h, wherein the carbon potential CP in a strong carburizing stage is 1.06+ / -0.3C%, and the carbon potential CP in a diffusion stage is 0.85+ / -0.03C%; 2, quenching: cooling the obtained carburized gear to 830+ / -5DEG C, samming for 25-35min, and quenching in 90+ / -10DEG C quenching oil; and 3, tempering: tempering the obtained quenched gear at 165+ / -5DEG C for 2-3h. The proper reduction of the carburizing temperature and the quenching temperature, the rising of the temperature of the quenching oil and the proper rising of the carburizing carbon potential are carried out on the premise of guaranteeing the quality of a carburized layer, so the carburizing time is not prolonged, and the energy consumption is reduced; and the appearance of black microstructures is prevented, so the surface hardness, the wear resistance and the fatigue strength of the gear are obviously improved, deformation is reduced, the driving balance of the gear is improved, noises are reduced, and the service life of the gear is prolonged.

The invention relates to a high-temperature variable-carbon potential quick carburizing treatment process for gear parts. The high-temperature variable-carbon potential quick carburizing treatment process comprises the steps as follows: strongly carburizing for the first time; diffusing for the first time; strongly carburizing for the second time; diffusing for the second time; cooling; quenching; cleaning; tempering; and taking out the parts, discharging and air-cooling. According to the high-temperature variable-carbon potential quick carburizing treatment process, a high-temperature variable-carbon potential method is adopted, so that the process time can be shortened by 20-30% under the condition that materials, part sizes and carburized layer depths are the same, that is, the efficiency is improved.

Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using a napthene hydrocarbon as the carburizing medium. The furnace is constructed to be generally transparent to the napthene so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The napthene is supplied in liquid form to fuel injectors which inject the liquid napthene as a vapor at duty cycles and firing orders to produce a uniform dispersion of the hydrocarbon gas about the work resulting in uniform carburizing of the workpieces. An in-situ methane infrared sensor controls the process. Hydrogen is added to the napthene to either assure full carbon potential and produce methane or to perform variable carburizing.

The invention relates to a surface refining process for a high-carbon chromium (GCr15) bearing after carbonitriding treatment, which is characterized by comprising the following steps: insulating a bearing ring for 1.5-3 hours at the temperature of 810-840 DEG C under the carbon and nitrogen atmosphere conditions that the carbon potential is 1.0-1.5 and the nitrogen potential is 2-6%, and then carrying out quenching, wherein the quenching temperature is 810-840 DEG C; heating the bearing ring to 500-600 DEG C, eliminating the stress and tempering for 2-3 hours; heating the bearing ring to 800-830 DEG C, insulating for 0.5-1.5 hours, and then carrying out quenching again, wherein the quenching temperature is 800-830 DEG C; and then, heating the bearing ring to 150-200 DEG C, and tempering for 2-3 hours. The two quenching processes are carried out by using oil of 30-100 DEG C. The invention has the advantage of refining the carbonitride penetrating into the surface of the bearing ring, thereby being more favorable for prolonging service life of the bearing.

The invention discloses a thermal insulation and auxiliary heating device for microwave sintering of ceramic cutter material. The device comprises a thermal insulation area which is formed by an outer-layer mullite box, high temperature resistant aluminum oxide fiber cotton and high temperature resistant aluminum oxide foam bricks, and an auxiliary heating area which is formed by silicon carbide, graphite and activated carbon powder. The device can bear the sintering temperature of almost 2000 DEG C during the sintering process, and the thermal insulation effect is excellent. The added graphite and the activated carbon powder can increase the carbon potential in a material sintering system, so as to prevent material oxidation and ensure material quality. By the reasonable arrangement of the auxiliary heating area, test pieces of different shapes and sizes can be formed in a single sintering process. The device has features of simple structure, good compatibility, safe and convenient use, good thermal insulation effect, short heating time, low cost, and easy commercialization.

Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using an unsaturated aromatic such as benzene as the carburizing medium. The unsaturated aromatic is gas phase hydrogenated into a napthenes, such as cyclohexane, which is metered into the furnace chamber proper and functions as the carburizing gas. The furnace is constructed to be generally transparent to the napthenes so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The unsaturated aromatic is supplied in liquid form to fuel injectors which inject the liquid aromatic as a vapor at duty cycles and firing orders to produce a uniform dispersion of the hydrocarbon gas about the work resulting in uniform carburizing of the workpieces. An in-situ methane infrared sensor controls the process. Excess hydrogen beyond what is required to hydrogenate the aromatic is added to the furnace chamber to either assure full carbon potential and produce methane or to perform variable carburizing. Hydrogenation occurs in a hydrogenation coil in fluid communication with the furnace chamber with temperature for the reaction set by the position of the hydrogenation coil in the furnace insulation.

The invention relates to a manufacturing method of a high-precision plunger, the material adopts alloy steel or bearing steel and the technology adopts the flow of machining, heat treatment and grinding; the specific heat treatment steps are that: the plunger is preheated at a temperature of 350-400 DEG C for 40-50 minutes; the plunger is placed into the carburization heat treating furnace, then the temperature is raised to 840 DEG C and is kept for 30 minutes, the carbon potential (CP) is controlled to be 0.4, then the temperature is raised to 880 DEG C and the carbon potential (CP) is raised to 0.8 and kept for 20 minutes, then a surface carburization is made under the furnace temperature of 880 DEG C and the CP of 0.8 for 180 minutes, then the carbon potential is reduced to 0.7 for ten minutes, the furnace temperature is kept at 880 DEG C, then the surface carburization is made under the furnace temperature of 880 DEG C and the CP of 0.7 for 30 minutes, then is cooled to 100 DEG C for 50 minutes, and finally the temperature is raised to 800 DEG C for 10 minutes and then the plunger is removed from the furnace after keeping for 50 minutes at the temperature of 800 DEG C; is quenched in the oil for 15-25 minutes, the oil temperature is kept at 80 DEG C; the plunger is rinsed; and finally is tempered in a tempering furnace for 170-190 minutes at the temperature of 175-185 DEG C. The invention is environment-protective and the manufactured plunger has high precision.

The invention relates to a heat treatment carburization process of carburizing steel. The heat treatment carburization process orderly comprises the following steps: pre-carburization (under the conditions of the temperature of 800-840 DEG C, the carbon potential of 0.9-1.3 and the time of 1-3 hours); circulating carburization (under the conditions of the temperature of 910-940 DEG C, the carbon potential of 0.9-1.3 and the time of 1-4 hours, cooling in an oil at the temperature of 50-140 DEG C, and circulating twice); diffusing and quenching (carburizing for diffusion under the conditions of the temperature of 910-940 DEG C, the carbon potential of 0.8-1.0 and the time of 1-3 hours, reducing the temperature to the range of 840-890 DEG C after diffusion, and after retaining the heat at the carbon potential of 0.8-1.0 for 0.5-2 hours, quenching and cooling in the oil at the temperature of 50-140 DEG C); and tempering (at 160-230 DEG C for 2-4 hours). According to the heat treatment carburization process, the special pre-carburization process is added and matched with the circulating carburization, so that lots of fine carbide particles can be formed in the surface carburized layer; the grain size is thinned to grade 9 from grade 7 and the surface wear resistance is greatly improved on the basis of satisfying the properties of the core.

The invention discloses a process method for controlling the non-martensite depth of a carburized workpiece. The process method comprises the steps of carburizing, ammonia introducing, primary quenching, high-temperature tempering, secondary quenching and low-temperature tempering for two times. According to the process method for controlling the non-martensite depth of the carburized workpiece, the carbon potential during carburizing is improved, and the proportion of the strong carburizing stage in the total carburizing time is increased, so that the internal oxidation depth in the carburizing atmosphere is decreased; in addition, a certain amount of ammonia is introduced in the final stage of carburizing and heat preservation, N atoms permeate into the surface of the workpiece, the hardenability of a workpiece carburized layer is improved, and hence formation of a non-martensite structure is effectively prevented; and meanwhile, after carburizing is conducted, the high-temperature tempering process is added between the two times of quenching processes, and the subsequent two times of low-temperature tempering processes are conducted, so that the content of surface layer residual austenite is effectively decreased, and the situation that the residual austenite does not meet the technical requirement is avoided.

The continuous micro deformation RE-carbon co-penetrating process for gear of automobile gear box is realized via making the pre-treated workpiece enter the different regions with RE co-penetrant in continuous carbonizing furnace at 840-890 deg.c. The workpiece is made to enter successively region-I for preheating and pre-penetrating; region-II and region-III with carbon potential of 1.15-1.25 % for carbonizing; region-IV with carbon potential of 0.8-1.05 % for diffusion treatment; and region-V with carbon potential of 0.8-1.05 % for waiting for discharging and quenching. The present invention is one controllable low temperature RE high concentration gas carbonizing process capable of resulting in optimal metallurgical structure, and has the advantages of high carbonizing rate, high efficiency and low power consumption.

The invention discloses a well type air seep carbon stove and improvement of process thereof. The invention is characterized in that a traditional well type air seep carbon stove is improved; a wind shield is arranged on a charging basket; and the distance between the wind shield and a fan is increased. When a carburizing agent composed of kerosene and methanol is used for carburizing workpieces made from material of 20 Cr or 20 CrMnTi, the carburizing process includes carburizing period and diffusion stage, the temperatures of which respectively are 930 DEG C plus or minus 10 DEG C, 900 DEG C plus or minus 10 DEG C. During the carburizing period, the carburizing agent is added with kerosene of 10.3 ml / m / min plus or minus 0.2 ml / m / min, and methanol of 3.4 ml / m / min plus or minus 0.2 ml / m / min; and the carbon potential in the stove is 1.05 percent plus or minus 0.05 percent. During the diffusion stage, kerosene is of 8.0 ml / m / min plus or minus 0.2 ml / m / min, methanol is of 4.6 ml / m / min plus or minus 0.2 ml / m / min, and the carbon potential in the stove is 0.95 percent plus or minus 0.05 percent; and the pressure in the stove during the carburizing period ranges from 1.0 kPa to 1.5 kPa. By using the traditional well type air seep carbon stove, the invention has the advantages of enhancing carburization speed, saving carburization time, improving product quality, and adequately decomposing and absorbing the carburizing agent, and hardly producing carbon soot in the stove during the whole carburizing period, with the best effect when carburized depth ranges from 0.9 mm to 1.25 mm.

The invention discloses a process for strengthening nodular cast ion and a finished product thereof. The process comprises the following steps of: putting cleaned nodular cast iron parts into a carburizing furnace; performing carbonitriding, namely adding methanol and ammonia at the temperature of between 800 and 840 DEG C, wherein the addition of the methanol is 80-120 drops / minute, the adding volume of the ammonia is 1 to 5 percent of the volume of the methanol cracked gas, the carbon potential is maintained to between 0.8 and 1.2 percent, and the processing time is 2 to 4 hours; and performing quenching to obtain a part finished product. In the carbonitriding process, the decarbonization preventing technological measure is adopted, the metallographic structure of the finished product comprises a surface layer, a sublayer and a substrate in turn, the surface layer is a granular or continuously distributed compound layer, the sublayer is hidden needle-like nitrogenous martensite, retained austenite and graphite, and the substrate is thin needle-like martensite, retained austenite and graphite. The process can improve the scratch resistance, wear resistance and contact fatigue strength, can effectively prevent full decarbonization during carbonitriding of the nodular cast ion, and has the advantages of low process difficulty and low production cost.

The invention discloses a thermal treatment method for carburizing and quenching of gearbox gears. The thermal treatment method includes the steps of A, carburizing, B, quenching and C tempering. In the step of A, carburizing, the gears are placed in a heating furnace, the temperature of the heating furnace is increased from the room temperature to the temperature of 850-900 DEG C for carburizing, and carburizing time is 2-5 h; the carburizing process includes a beginning stage, a strong carburizing stage and a diffusion stage; the carbon potential (CP) of the beginning stage is 0.9-1 C%, the CP of the strong carburizing stage is 1-1.1 C%, and the CP of the diffusion stage is 0.8-0.9 C%; the time of the beginning stage is 12-15 min, the time of the strong carburizing stage is 200-220 min, and the time of the diffusion stage is 20-40 min. In the step of B, quenching, the carburized gears are cooled to 810-850 DEG C, then temperature equilibrium is carried out for 20-40 min, and then the gears are quenched in quenching oil with the temperature being 85-95 DEG C. In the step C, tempering, the quenched gears are subjected to tempering at the temperature of 155-170 DEG C for 1-2 h.

The invention provides a heat treatment process of a GCr15 steel bearing ring, comprising the following steps of: (1) heating a bearing to 830 DEG C-860 DEG C and keeping the temperature; (2) quenching in oil; and (3) tempering and keeping the temperature. By adopting the selection of the tempering temperature and the temperature keeping time and the control of carbon potential, the invention ensures that under the condition of quasi high-temperature tempering, at the working temperature of 160 DEG C, the size variation of an inner-ring roller path and an outer-ring roller path of the heat-treated GCr15 steel bearing ring is not more than 0.008 mm, and the hardness is not less than 57HRC and is more than that of a high-temperature tempered GCr15 steel bearing ring. Meanwhile, the heat treatment process is simple and has lower cost compared with the traditional low-temperature treatment and high-temperature tempering process.

Disclosed is a carbon steel sheet which contains not less than 0.20% by mass but not more than 0.45% by mass of C, not less than 0.05% by mass but not more than 0.8% by mass of Si, not less than 0.85% by mass but not more than 2.0% by mass of Mn, not less than 0.001% by mass but not more than 0.04% by mass of P, not less than 0.0001% by mass but not more than 0.006% by mass of S, not less than 0.01% by mass but not more than 0.1% by mass of Al, not less than 0.005% by mass but not more than 0.3% by mass of Ti, not less than 0.0005% by mass but not more than 0.01% by mass of B, and not less than 0.001% by mass but not more than 0.01% by mass of N. The carbon steel sheet has a K value, which is expressed by 3C + Mn + 0.5Si, of not less than 2.0, a surface hardness, namely a Rockwell hardness of not more than 77 on the B scale, and an average N content of not more than 100 ppm in the region from the surface to the depth of 100 [mu]m. The carbon steel sheet is carburized in a carburizing atmosphere having a carbon potential of not more than 0.6.

The invention relates to a heat treatment method, in particular to a high-carbon chrome bearing part surface intensified heat treatment method. The heat treatment method adopts the following steps: firstly, carbonitriding treatment: at the temperature of 830 to 850 DEG C, through adding 0.95 to 1.2C percent of carbon potential and 0.2 to 0.4m<3> / h of ammonia gas, a GCr15 bearing part is carbonitrided for 6 to 8 hours and then oil quenching is performed; secondly, high temperature tempering: at the temperature of 580 DEG C with the tolerance of 10 DEG C, high temperature tempering is implemented for 1.5 to 2.5 hours, and the bearing part is discharged from the furnace and air-cooled; thirdly, at the temperature of 820 DEG C with the tolerance of 10 DEG C, in the protective atmosphere of 0.95 to 1.2C percent of carbon potential and 0.2 to 0.4m<3> / h of ammonia gas, and the conventional secondary high temperature tempering is carried out. The invention has the advantages that a penetrating layer of 0.4 to 0.65mm can be achieved on the part surface through the method, in the obtained carbon nitrogen compound, the residual austenite amount is not less than 20 percent, the carbon nitrogen compound has 12 to 13 grade ultra fine grain size, the particle is difficult to differentiate under the optical microscope of 500 times, and the wear resistance and the anti-rolling contact fatigue lifetime of the bearing under the polluted lubrication environment are enhanced.

The invention provides a heat treatment process for surface hardening and carbonitriding of hydraulic parts, which includes the following steps: a washing the hydraulic parts preparing for heat treatment to remove greasy dirt; b warming a carburizing multi-purpose furnace, and performing pre-carburizing treatment; c putting the hydraulic parts washed cleanly through the step a in the carburizing multi-purpose furnace, and performing strong carburizing; d adjusting carbon potential after the strong carburizing to perform diffusion; e putting the hydraulic parts after carbonitriding in the stepd in a quenching chamber of the carburizing multi-purpose furnace to be quenched, filtering oil and discharging from the furnace; and f washing the hydraulic parts of the step e, and putting the hydraulic parts in a tempering furnace to be tempered to obtain products.

The invention discloses a process for machining parts of an automobile gear box by using 20CrMnTi steel. The process is characterized by comprising the following steps of forging, carrying out preheat treatment, mechanically machining, carburizing and quenching, and grinding, wherein in a carburizing and quenching process, carburization is carried out at a temperature of 910-930 DEG C and a dripping amount of a carburizer is monitored when the carburization is carried out, so that the carbon potential in a carburizing furnace is controlled within a range from 0.85 to 1.0; the temperature of the carburizing furnace is cooled to a temperature of 830-850 DEG C; a quenching process is executed directly after a material is discharged and pre-cooled, so that the residual austenitic amount is controlled to be less than or equal to 10%; a tempering temperature is raised, wherein the tempering temperature is less than or equal to 250 DEG C; temperature-preservation time in a tempering process is prolonged to ensure the rigidity of a carburizing layer; and finally, shot blasting is carried out to improve pressing stress. With the adoption of the treatment process, no crack occurs in a grinding process and the percent of pass of machined parts reaches 100%.

The invention provides a multi-segment deep carburization method of a large heavy-duty gear. The method comprises the following steps of primary intensive carburization, primary diffusion, secondary intensive carburization, secondary diffusion, cooling, quenching, washing, tempering, discharging from a furnace and air cooling. The deep carburization thermal treatment method for a gear type component, disclosed by the invention, adopts a multi-segment temperature-rising variable carbon potential method and can be used for effectively solving the problem that a large bulk of network carbide is easy to generate on a carburization layer on the surface of the gear, obtaining fine particle-like carbides distributed in a diffused manner, improving gold phase tissues on the surface of the gear, improving the hardness and wear resistance of the surface of the gear, also obtaining a high carburization speed, shortening the thermal treatment time, reducing the energy consumption and improving the production efficiency.

The invention provides a thermal treatment technology for a clutch disc hub, which comprises the following steps: S1, selecting 20CrMo as the material of the clutch disc hub, placing the clutch disc hub made from 20CrMo into a heating furnace, heating clutch disc hub made from 20CrMo, and controlling the CP (Carbon Potential)of furnace gas to be 0.5-0.7; S2, when the clutch disc hub is heated to 850-870DEG C, pumping nitrogen, methyl alcohol and propane into the furnace; controlling the CP of furnace gas to 0.9-1.1, and keeping the state for 10min; S3, maintaining the temperature of the clutch disc hub made from 20CrMo to 850-870DEG C, and further pumping ammonia gas into the furnace, wherein the flow value of ammonia gas is 0.31-0.39m<3> / h; controlling the CP of furnace gas to 0.9-11, and keeping the state for 150-170min; S4, performing oil quenching of the clutch disc hub made from 20CrMo; then tempering the clutch disc hub made from 20CrMo, wherein the tempering temperature is controlled to 250-270DEG C, and the tempering time is controlled to 110-130min; then carrying out air cooling on the clutch disc hub made from 20CrMo to normal temperature; and S5, performing shot blasting treatment of the cooled clutch disc hub made from 20CrMo.

This invention relates to surface carbonitriding treatment on high carbon chromium (GCr15) bearing rings, which comprises the steps of: placing the high carbon chromium (GCr15) bearing rings in a thermal treatment furnace (carbon potential and nitrogen potential are 1.0-1.5, 2-6%, respectively), keeping the temperature at 810-830 deg.C for 1.5-3 hrs, quenching and tempering at 150-180 deg.C for 1.5-4 h. This invention can increase the content of the residual austenite in the bearing rings so that the surface exists residual stress, which can significantly extend the service life of the bearings.

The invention discloses a heat disposing technique of gear coat of automobile gear box synchronizer, which comprises the following steps: copenetrating carbon and nitrogen at 780-850 deg. c; quenching; cleaning; annealing; testing; setting the carbon potential at 0. 50-1. 0%, nitrogen adding quantity at 5-12m3 / h, carbinon adding quantity at 4-7L / h, propane adding quantity at 0. 5-0. 9m3 / h and ammonia gas adding quantity at 0-30L / h.