CN115369352A - Continuous furnace carburizing process - Google Patents
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- 238000005255 carburizing Methods 0.000 title claims abstract description 85
- 238000000034 method Methods 0.000 title claims abstract description 44
- 230000008569 process Effects 0.000 title claims abstract description 41
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 132
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 70
- 238000010438 heat treatment Methods 0.000 claims abstract description 35
- 239000003345 natural gas Substances 0.000 claims abstract description 35
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 32
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 32
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 14
- 239000000463 material Substances 0.000 claims abstract description 14
- 238000009423 ventilation Methods 0.000 claims abstract description 4
- 238000005192 partition Methods 0.000 claims abstract description 3
- 238000009792 diffusion process Methods 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 230000004907 flux Effects 0.000 claims description 4
- 230000035515 penetration Effects 0.000 claims description 4
- 230000035699 permeability Effects 0.000 claims description 4
- 230000005484 gravity Effects 0.000 claims description 3
- 238000011112 process operation Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 29
- 230000002829 reductive effect Effects 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 7
- 239000003054 catalyst Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000005336 cracking Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 229910000734 martensite Inorganic materials 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
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- 238000003908 quality control method Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 238000010561 standard procedure Methods 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 238000004523 catalytic cracking Methods 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
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- 230000003247 decreasing effect Effects 0.000 description 1
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- 238000007689 inspection Methods 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 239000003915 liquefied petroleum gas Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 239000011593 sulfur Substances 0.000 description 1
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- 239000002699 waste material Substances 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Abstract
The invention relates to a continuous furnace carburizing process, which adopts a continuous carburizing furnace and a gravity-flow methanol tank, adopts methanol as a carburizing agent for drip-feed carburizing, adopts a furnace body with a five-partition structure, and comprises the following steps: s1, setting the pressure parameter of a methanol tank to be 20-30 Kpa, and realizing stable methanol self-flow drip feeding into a furnace; s2, setting each area of the continuous carburizing furnace; s3, setting the temperature of each area of the continuous carburizing furnace, the flow of a carburizing agent, the carbon potential, the exhaust ratio and the comprehensive ventilation ratio parameter, and completing furnace opening; s4, opening the furnace normally and heating, feeding methanol and natural gas into each area according to set parameters, adjusting the flow of the natural gas after operation until the set carbon potential parameters are reached, and completing debugging; and S5, heating to the set working temperature, pushing materials into the furnace, and finishing the carburizing operation. The invention adopts the drip-feed carburizing and uses the continuous carburizing furnace, thereby not only having stable process, obviously improving the quality of the treated product, but also having low running cost and simple process operation.
Description
Technical Field
The invention relates to the technical field of metal heat treatment processes, in particular to a continuous furnace carburizing process.
Background
At present, in the automobile industry of China, strict requirements are imposed on the process and the quality of gear machining. The processing technology of the gear needs to meet the requirements of the existing industry standard JB/T7516-1994 & lt & ltGear gas carburizing heat treatment technology and quality control & gt of China. The quality of the gear needs to meet the current industry standard JB/T7516-1994 & lt & ltGear gas carburizing heat treatment process and quality control & gt & lt & gt of China and the QC/T262-1999 & lt & gt metallographic examination & gt of automobile carburized gears in the automobile industry.
According to the current standard regulation in China, the drip gas carburizing method for the low-carbon alloy steel makes regulations and requirements on equipment, raw materials and specific processes. The carburizing equipment can adopt a continuous gas carburizing furnace, a sealed box furnace, a well type gas carburizing furnace and the like. When carburizing is carried out in a controllable atmosphere, the raw materials of the endothermic atmosphere are natural gas and liquefied petroleum gas, and the components of the endothermic atmosphere meet the requirements of JB/T9207-1999. The carburized raw material should have stable components, low harmful impurities, and sulfur content below 0.02%, and be used after being checked to meet the requirements.
Based on the strict standard requirements of China on gear machining in the automobile industry, the carburizing process adopted by the existing gear is as follows. Adopting atmosphere carburization, and selecting heat absorption type protective atmosphere plus natural gas; the method comprises the following specific steps: step one, natural gas and air are used as raw materials and mixed according to the proportion of 1:2.38, and the mixture is sent into a gas generating furnace to generate CO (20%) + H under the action of a catalyst 2 (40％)+N 2 (40%) of the mixed gas is fed into a carburizing furnace; step two, raising the furnace temperature to 800 ℃, and starting to supply gas; air supply and exhaust of an empty furnace for 24 hours, and the flow rate of each area is 8m 3 H; step three, raising the temperature to 850 ℃, and feeding natural gas into the strong permeation area, wherein each area is 0.4-0.6 m 3 Fixing carbon after 8-12 hours, and adjusting the natural gas flow according to the carbon fixing result until a set carbon formula is reached; and step four, heating to the working temperature, and pushing materials into the furnace.
After carburizing products according to the prior art method, the following defects mainly exist: 1. the gas production of the gas generating furnace has an upper limit, and more design redundancy is reserved for subsequent equipment addition, so that waste is caused; 2. in order to improve the catalytic efficiency, the gas generator catalyst is usually in the form of porous particles, and is easily pulverized when the water vapor content is high, resulting in gas blockage or blockage. In order to avoid the situation, a cold dryer is additionally arranged; or periodically cleaning the catalyst; 3. the gas generator has high use temperature (1140 ℃), and the electrical elements and the catalytic tank body have high aging speed; at the same time, the gas production requires waterA cooling water channel is additionally connected when the temperature is low; the temperature of a gas production outlet is high (1140 ℃), high water pressure (0.2-0.4 MPa) and water quantity are needed, a high-pressure water pump needs to be configured, and water leakage risk exists; 4. gas production inspection requires an infrared instrument, and CO is checked 2 The content controls the gas composition, and the catalyst is easily clogged after being pulverized.
Disclosure of Invention
The invention aims to overcome at least one defect of the technology and provides a continuous furnace carburizing technology, which adopts drop-feed carburizing and uses a continuous carburizing furnace, so that the technology is stable, the quality of the treated product is obviously improved, the operation cost is low, and the technology operation is simple.
In order to achieve the technical purpose, the technical scheme of the invention provides a continuous furnace carburizing process, the continuous furnace carburizing process adopts a continuous carburizing furnace and a gravity-flow methanol tank, methanol is adopted as a carburizing agent for drip-feed carburizing, the continuous carburizing furnace adopts a furnace body with a five-partition structure, and the continuous carburizing process comprises the following steps:
s1, setting the pressure parameter of a methanol tank to be 20-30 Kpa, and realizing stable methanol self-flow drip feeding into a furnace;
s2, setting each zone of the continuous carburizing furnace according to the division of a heating zone, a strong permeation and diffusion zone, a diffusion zone and a uniform temperature zone;
s3, setting the temperature of each area of the continuous carburizing furnace, the flow of a carburizing agent, the carbon potential, the exhaust ratio and the comprehensive ventilation ratio parameter, and completing furnace opening;
s4, heating the main furnace to 850 ℃ according to normal furnace opening and heating, feeding methanol and natural gas into each zone according to set parameters, adjusting the natural gas flow according to a carbon determination result after operation until a set carbon potential parameter is reached, and completing debugging;
and S5, heating to the set working temperature, pushing materials into the furnace, and finishing the carburizing operation.
On the basis of the technical scheme, the invention can be further improved as follows.
Optionally, in the step S1, the filling amount of methanol in the methanol tank is 700 to 800L each time.
Optionally, in step S3, according to the sequence of the heating region, the strong permeation and diffusion region, the diffusion region, and the uniform temperature region, the temperature parameters of each region are as follows: 850-900 ℃, 900-950 ℃, 850-900 ℃ and 840-860 ℃, and the flux parameters of the permeability agent in each region are as follows: 20-30 ml/min, 25-35 ml/min and 20-30 ml/min, wherein the carbon potential parameters of each area are as follows: none, 1.20-1.40%, 1.00-1.20%, 0.90-1.00%, 0.75-0.85%; and natural gas is introduced into the strong permeation area and the strong permeation and diffusion area.
Further optionally, in step S3, air is introduced into the diffusion region and the uniform temperature region to adjust the carbon potential.
Further optionally, in step S3, the exhaust of the continuous carburizing furnace is set to be 3 after 7, the air exchange is performed for 0.9 times/hour, the material pushing period of the continuous carburizing furnace is 23 to 25 minutes, and the furnace pressure is 10 to 15mm water column.
Further optionally, in the step S3, the temperature parameters of each zone are: 880-890 ℃, 920-930 ℃, 880-890 ℃ and 850-855 ℃, and the parameters of the flux of the permeability agent in each area are as follows: 24-26 ml/min, 28-30 ml/min, 30-32 ml/min, 28-30 ml/min and 24-26 ml/min, wherein the carbon potential parameters of each area are as follows: none, 1.20-1.25%, 1.05-1.10%, 0.95-1.00%, 0.80-0.85%.
Further optionally, in step S3, the blowing-in includes the following steps:
a. gradually heating the main furnace to 800 ℃, then feeding methanol, and exhausting after 24 hours of air feeding of an empty furnace;
b. heating to 850 ℃, feeding natural gas into each area for pre-carburization, fixing carbon after 12 hours, and adjusting the natural gas flow according to the carbon fixing result until a set carbon formula is achieved;
c. and (5) heating to the set parameter temperature, and pushing materials into the furnace.
Further optionally, in the step a, the front door is opened 1 time per hour during the exhaust period, and the exhaust is accelerated.
Further optionally, in the step a, when the methanol is fed, the feeding flow rate of the methanol is 40ml/min; in said step b, the natural gas is fedThe feeding flow rate is 0.8m 3 /h。
Further optionally, in the step S3, the flow parameters of the natural gas include: strong penetration area 0.6-0.8 m 3 H, strong penetration and diffusion area 0.4-0.6 m 3 /h。
Compared with the prior art, the invention has the beneficial effects that:
1) The invention directly uses the drip type carburization, does not need gas catalytic cracking equipment and supporting facilities thereof, effectively reduces the purchase, maintenance and use cost of the equipment, and adopts the self-flowing drip type equipment, except a liquid storage tank and an explosion-proof pump, has no other hardware maintenance and extremely low use cost;
2) Methanol is used as carrier gas, the price is low, the purchase and the transportation are convenient, natural gas is used as enriched gas, a propane gas station or acetone of a pipe product is not needed, and potential safety hazards caused by storage and transportation of dangerous goods are reduced;
3) Methanol is used as carrier gas, the components are stable and uniform, the stability of furnace gas is good, the CO content of pure methanol in the atmosphere furnace gas is about 29 percent, the CO content of the heat absorption type protective atmosphere furnace gas is about 18 percent, the number of active carbon atoms is obviously increased, the carburizing speed can be improved by about 5 percent, and all quality indexes of the carburized gear are better than those of the prior art;
4) The air change ratio of the main furnace is effectively reduced and is far lower than that of the prior art, and the operation cost and carbon emission of the main furnace are directly reduced; meanwhile, a gas cracking furnace is not needed, so that the operation cost can be further reduced; finally, the invention also effectively reduces the dosage of the penetrant, and the cost of the penetrant is effectively reduced by using methanol as the penetrant.
Drawings
FIG. 1 is a graph showing a hardness distribution of a surface-core portion of a product prepared in example 1 of the present application;
FIG. 2 is an electron microscope image of the product prepared in example 1 of the present application for detecting surface martensite;
FIG. 3 is an electron microscope image of a product prepared in example 1 of the present application for detecting surface tempered martensite and retained austenite;
FIG. 4 is an electron micrograph of a test core of a product prepared in example 1 of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention designs a continuous furnace carburizing process, which adopts a continuous carburizing furnace and a gravity-flow methanol tank, adopts methanol as a carburizing agent for drip-feed carburizing, adopts a furnace body with a five-division structure, and comprises the following steps:
s1, setting the pressure parameter of a methanol tank to be 20-30 Kpa, and realizing stable methanol self-flow drip feeding into a furnace;
s2, setting each area of the continuous carburizing furnace according to the division of a heating area, a strong permeation and diffusion area, a diffusion area and a uniform temperature area;
s3, setting the temperature of each area of the continuous carburizing furnace, the flow of a carburizing agent, the carbon potential, the exhaust ratio and the comprehensive ventilation ratio parameter, and completing furnace opening;
s4, heating the main furnace to 850 ℃ according to normal furnace opening and heating, feeding methanol and natural gas into each zone according to set parameters, adjusting the natural gas flow according to a carbon determination result after operation until a set carbon potential parameter is reached, and completing debugging;
and S5, heating to the set working temperature, pushing materials into the furnace, and finishing the carburizing operation.
Before the invention, the gear processing in the existing automobile industry is carried out by adopting the standard process recorded in the background technology according to the current standard of China. A gas cracking furnace is used, an endothermic atmosphere is used, and a catalyst is used for carburizing. The cost of the existing process is very high.
The gas cracking furnace adopted in the prior art is calculated according to 70KW of heating power, 5KW of a cooling water pump motor, 1000KWh of daily power consumption, 400kVA of capacity of a power transformer, 8500 yuan of monthly power consumption cost and 9200 yuan of annual cost. In addition, the catalyst needs to be replaced 2 times per year, the quenching tank body needs to be replaced 1 time per year 3 years and the likeFittings, etc., with a cost of about 30000 yuan per year. Only one gas cracking furnace is used, and the annual cost of each furnace exceeds 12 ten thousand yuan. The natural gas consumption per hour of the endothermic protective atmosphere adopted by the prior art is about 7m 3 The monthly dose is about 5000m 3 The cost per year is about 20 ten thousand yuan, plus the corresponding losses in use. Namely, the running cost of the production line per year exceeds 30 ten thousand yuan, and the cost is extremely high.
In addition, there are problems such as catalysis based on the problems of the process itself, and the composition of the natural gas currently supplied is not stable using natural gas, so that the quality of carburization in the existing process is difficult to control. In the prior art, when the gear carburizing processing is carried out, the difference of the surface hardness of the products in the same batch is generally over 15 percent, the difference of the maximum carburized layer depth is over 14 percent, and the quality of the products is extremely unstable. The product rate meeting the standard requirement of the industrial standard JB/T7516-1994 Gear gas carburizing heat treatment process and the quality control thereof is less than 85 percent according to the standard method detection of QC/T262-1999 automobile carburizing gear metallographic examination.
Based on this, the inventors have studied the carburizing process carefully, and have devised the present application. Instead of adopting the standard process method of the industry standard in the field, methanol is used as a carburizing agent, an instillation type carburizing mode is used, and a continuous carburizing furnace is modified to change the subarea thereof. Through the detailed design of the carburizing parameters, all the qualities of the process can completely meet the requirements of the current standard.
The following are examples of the present invention.
Example 1
The carburizing apparatus of the present embodiment is designed as follows:
firstly, a methanol tower is built, a methanol storage tank is installed, about 700 liters of methanol is filled every time, the methanol automatically flows into the continuous carburizing furnace by the fall of the methanol tower according to the gravity, the fall is controlled, the pressure is controlled to be 20-30 KPa, and the stable supply is realized. And a gravity flow structure is adopted, so that the cost can be effectively reduced.
And secondly, transforming the continuous carburizing furnace, dividing the continuous carburizing furnace into five zones according to the division of a heating zone, a strong permeation and diffusion zone, a diffusion zone and a uniform temperature zone, and connecting and installing pipelines such as a methanol supply pipeline, a natural gas pipe, an air pipe and the like.
The carburizing apparatus operating parameter settings of the present embodiment are shown in table 1.
Table 1 table of parameters of example 1
After the construction is finished and parameters are set, firstly, the furnace is opened and debugged, and the following steps are adopted:
a. gradually heating the main furnace to 800 ℃, then feeding methanol, and exhausting after 24 hours of air feeding of an empty furnace;
b. heating to 850 ℃, feeding natural gas into each area for pre-carburization, fixing carbon after 12 hours, and adjusting the natural gas flow according to the carbon fixing result until a set carbon formula is achieved;
c. and (5) heating to the set parameter temperature, and pushing materials into the furnace.
Then carrying out production debugging, and adopting the following steps:
d. heating the main furnace to 850 ℃ according to a normal heating process;
e. feeding methanol and natural gas into each zone according to a normal process, and adjusting the flow of the natural gas according to a carbon determination result after 8 hours until a carbon determination formula is reached;
f. and (4) heating to the working temperature, and pushing the materials into the furnace.
And after all debugging is finished, formally pushing the materials into the furnace, and carburizing according to set parameters.
A main gear of the J6P gear pump which finishes carburizing processing is randomly taken as a sample, the surface-core hardness distribution of the main gear is detected, and then the metallographic phase of the main gear is detected according to a standard method of QC/T262-1999 metallographic examination of automobile carburized gears. The results of the detection are shown in FIGS. 1 to 4.
As shown in fig. 1, the surface-core hardness distribution of the product is uniformly decreased. As shown in FIGS. 2-4, the effective depth of the quench hardening layer of the product is about 1.2mm; carbide grade 1-2, martensite plus retained austenite grade 3, and surface non-martensite depth 0.01-0.02 mm.
Example 2
This example is substantially similar to the apparatus and process used in example 1. The difference is in parameter setting, which is shown in table 2 in this embodiment.
Table 2 table of parameters of example 2
Example 3
This example is substantially similar to the apparatus and process used in example 1. The difference is in parameter setting, which is shown in table 3 in this embodiment.
Table 3 table of parameters of example 3
Example 4
This example is substantially similar to the apparatus and process used in example 1. The difference is in parameter setting, which is shown in table 4 in this embodiment.
Table 4 table of parameters of example 4
Example 5
This example is substantially similar to the apparatus and process used in example 1. The difference is in parameter setting, which is shown in table 5 in this embodiment.
Table 5 table of parameters of example 5
The main gear of the J6P gear pump was used as a processing target, and 100 gears were continuously carburized by the processes of examples 1 to 5, respectively, and the material pushing cycle was about 24 minutes. The surface hardness difference and the maximum carburized layer depth difference of the products processed in the examples 1 to 5 are detected, the surface hardness difference can be controlled within 3 percent, and the maximum carburized layer depth difference can be controlled within 5 percent.
The existing process is used as a comparative example, the same 100 gears are processed, the material pushing period is about 45 minutes, the surface hardness difference and the maximum carburized layer depth difference of the product are detected, the surface hardness difference is more than 12%, and the maximum carburized layer depth difference is more than 13%.
It can be seen that the process stability of the present application is far superior to the prior art. Compared with the product processed in the example 1, the product randomly selected in the prior art has far lower surface hardness than the product processed in the example 1, regardless of metallographic phase.
By adopting the process, taking example 1 as an example, a gas cracking furnace is not needed, the consumption of natural gas is greatly reduced, the overall operation cost is basically consistent with that of the prior art, the consumption of the carburizing agent methanol is about 4.5 tons every month and 13500 yuan, and the consumption of the natural gas and a small amount of air is added, so that the month does not exceed 15000 yuan and the year does not exceed 18 ten thousand yuan. Compared with the prior art, the cost is saved by more than 12 ten thousand yuan and is reduced by more than 40 percent.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. The continuous furnace carburizing process is characterized by adopting a continuous carburizing furnace and a gravity-fed methanol tank, adopting methanol as a carburizing agent for drip-feed carburizing, adopting a furnace body with a five-partition structure, and comprising the following steps:
s1, setting the pressure parameter of a methanol tank to be 20-30 Kpa, and realizing stable methanol self-flow drip feeding into a furnace;
s2, setting each zone of the continuous carburizing furnace according to the division of a heating zone, a strong permeation and diffusion zone, a diffusion zone and a uniform temperature zone;
s3, setting the temperature of each area of the continuous carburizing furnace, the flow of a carburizing agent, the carbon potential, the exhaust ratio and the comprehensive ventilation ratio parameter, and completing furnace opening;
s4, heating the main furnace to 850 ℃ according to normal furnace opening and heating, feeding methanol and natural gas into each zone according to set parameters, adjusting the natural gas flow according to a carbon determination result after operation until a set carbon potential parameter is reached, and completing debugging;
and S5, heating to the set working temperature, pushing materials into the furnace, and finishing the carburizing operation.
2. The continuous carburizing process according to claim 1, wherein in step S1, the amount of methanol in the methanol tank per filling is 700 to 800L.
3. The continuous carburizing process according to claim 1, wherein in step S3, the temperature parameters of the heating zone, the strong carburizing and diffusing zone, the diffusing zone and the uniform temperature zone are as follows: 850-900 ℃, 900-950 ℃, 850-900 ℃ and 840-860 ℃, and the flux parameters of the permeability agent in each region are as follows: 20-30 ml/min, 25-35 ml/min and 20-30 ml/min, wherein the carbon potential parameters of each area are as follows: none, 1.20-1.40%, 1.00-1.20%, 0.90-1.00%, 0.75-0.85%; and natural gas is introduced into the strong permeation area and the strong permeation and diffusion area.
4. The continuous furnace carburizing process according to claim 3, wherein in step S3, air is introduced into the diffusion zone and the temperature equalizing zone for adjusting the carbon potential.
5. The continuous carburizing process according to claim 3, wherein in step S3, the exhaust of the continuous carburizing furnace is set to be 3 after 7, the air exchange is performed for 0.9 times/hour, the material pushing period of the continuous carburizing furnace is 23 to 25 minutes, and the furnace pressure is 10 to 15mm water column.
6. The continuous furnace carburizing process according to claim 3, wherein in the step S3, the temperature parameters of each zone are as follows: 880-890 ℃, 920-930 ℃, 880-890 ℃ and 850-855 ℃, and the parameters of the flux of the permeability agent in each area are as follows: 24-26 ml/min, 28-30 ml/min, 30-32 ml/min, 28-30 ml/min and 24-26 ml/min, wherein the carbon potential parameters of each area are as follows: none, 1.20-1.25%, 1.05-1.10%, 0.95-1.00%, 0.80-0.85%.
7. The continuous furnace carburizing process according to claim 6, wherein in step S3, the furnace opening comprises the following steps:
a. gradually heating the main furnace to 800 ℃, then feeding methanol, and exhausting after 24 hours of air feeding of an empty furnace;
b. heating to 850 ℃, feeding natural gas into each area for pre-carburization, fixing carbon after 12 hours, and adjusting the natural gas flow according to the carbon fixing result until a set carbon formula is achieved;
c. and (5) heating to the set parameter temperature, and pushing materials into the furnace.
8. The continuous furnace carburizing process according to claim 7, wherein in the step a, the front door is opened 1 time per hour during the exhaust period, and the exhaust is accelerated.
9. The continuous furnace carburizing process according to claim 7, wherein in the step a, when methanol is supplied, the supply flow rate of methanol is 40ml/min; in the step b, when the natural gas is fed, the feeding flow rate of the natural gas is 0.8m 3 /h。
10. The continuous furnace carburizing process according to claim 3, wherein in the step S3, the natural gas is introduced with the flow parameters as follows: strong penetration area 0.6-0.8 m 3 H, strong penetration and diffusion area 0.4-0.6 m 3 /h。
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1478984A (en) * | 1974-11-27 | 1977-07-06 | Lucas Ltd Joseph | Gas carburusing |
| CN2295764Y (en) * | 1997-04-17 | 1998-10-28 | 阎牧夫 | Continuous rare earth accelarator feeding unit of air status controlling carburizing apparatus |
| JP2004010945A (en) * | 2002-06-05 | 2004-01-15 | Koyo Seiko Co Ltd | Continuous carburizing furnace |
| CN101021000A (en) * | 2006-02-15 | 2007-08-22 | 林明清 | Methanol dropping decomposition furnace |
| CN102191451A (en) * | 2011-04-19 | 2011-09-21 | 哈尔滨意锋稀土材料开发有限公司 | Double-hearth continuous rare earth carburizing equipment and process thereof |
| CN102373400A (en) * | 2011-10-25 | 2012-03-14 | 哈尔滨汇隆汽车箱桥有限公司 | Heat treatment method of spiral bevel gear of cargo truck on double-row rare earth carburization equipment |
| CN113913731A (en) * | 2021-11-12 | 2022-01-11 | 陕西柴油机重工有限公司 | Press-in type controllable atmosphere generating device |
-
2022
- 2022-08-24 CN CN202211018753.6A patent/CN115369352A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1478984A (en) * | 1974-11-27 | 1977-07-06 | Lucas Ltd Joseph | Gas carburusing |
| CN2295764Y (en) * | 1997-04-17 | 1998-10-28 | 阎牧夫 | Continuous rare earth accelarator feeding unit of air status controlling carburizing apparatus |
| JP2004010945A (en) * | 2002-06-05 | 2004-01-15 | Koyo Seiko Co Ltd | Continuous carburizing furnace |
| CN101021000A (en) * | 2006-02-15 | 2007-08-22 | 林明清 | Methanol dropping decomposition furnace |
| CN102191451A (en) * | 2011-04-19 | 2011-09-21 | 哈尔滨意锋稀土材料开发有限公司 | Double-hearth continuous rare earth carburizing equipment and process thereof |
| CN102373400A (en) * | 2011-10-25 | 2012-03-14 | 哈尔滨汇隆汽车箱桥有限公司 | Heat treatment method of spiral bevel gear of cargo truck on double-row rare earth carburization equipment |
| CN113913731A (en) * | 2021-11-12 | 2022-01-11 | 陕西柴油机重工有限公司 | Press-in type controllable atmosphere generating device |
Non-Patent Citations (1)
| Title |
|---|
| 王迎春等: "《表面科学与工程》", vol. 1, 华东理工大学出版社, pages: 178 - 179 * |
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