CN113106377A - Heat treatment method for improving carburization internal oxidation of metal parts - Google Patents
Heat treatment method for improving carburization internal oxidation of metal parts Download PDFInfo
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- 239000002184 metal Substances 0.000 title claims abstract description 118
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 118
- 238000010438 heat treatment Methods 0.000 title claims abstract description 87
- 238000000034 method Methods 0.000 title claims abstract description 81
- 230000003647 oxidation Effects 0.000 title claims abstract description 46
- 238000007254 oxidation reaction Methods 0.000 title claims abstract description 46
- 238000011282 treatment Methods 0.000 claims abstract description 176
- 238000001816 cooling Methods 0.000 claims abstract description 50
- 238000009792 diffusion process Methods 0.000 claims abstract description 28
- 238000005496 tempering Methods 0.000 claims abstract description 27
- 238000002791 soaking Methods 0.000 claims abstract description 24
- 238000010791 quenching Methods 0.000 claims abstract description 22
- 230000000171 quenching effect Effects 0.000 claims abstract description 22
- 238000004140 cleaning Methods 0.000 claims abstract description 19
- 238000007599 discharging Methods 0.000 claims abstract description 17
- 238000001764 infiltration Methods 0.000 claims abstract description 5
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 210
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 88
- 238000005255 carburizing Methods 0.000 claims description 83
- 239000001294 propane Substances 0.000 claims description 44
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 43
- 229910052799 carbon Inorganic materials 0.000 claims description 43
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- 239000012530 fluid Substances 0.000 claims description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 6
- 239000003350 kerosene Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 3
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 3
- 230000008595 infiltration Effects 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 32
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 16
- 239000001301 oxygen Substances 0.000 description 16
- 229910052760 oxygen Inorganic materials 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 229910052737 gold Inorganic materials 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 238000011056 performance test Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- KZNMRPQBBZBTSW-UHFFFAOYSA-N [Au]=O Chemical compound [Au]=O KZNMRPQBBZBTSW-UHFFFAOYSA-N 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 229910001922 gold oxide Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000007669 thermal treatment Methods 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
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/58—Oils
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
- C21D3/02—Extraction of non-metals
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Abstract
The invention provides a heat treatment method for improving carburization internal oxidation of a metal part, belongs to the technical field of heat treatment, and can solve the technical problems that the furnace entering cooling and heating process is too simple, the carburization temperature is too high, the treatment time is longer, and further the internal oxidation quality of the surface of the treated metal part is deteriorated in the conventional heat treatment method for the metal part. The heat treatment method comprises the following steps: cooling treatment in a furnace, heating treatment in the furnace, high-temperature carburization and forced infiltration treatment, high-temperature carburization and diffusion treatment, furnace cooling and soaking treatment, quenching and cleaning treatment, low-temperature tempering treatment, furnace discharging and air cooling and the like. The method has the characteristics of simple and convenient operation, short time consumption and the like, and can improve the oxidation quality in the surface of the metal part. The invention can be applied to the aspect of the heat treatment process of the metal parts.
Description
Technical Field
The invention belongs to the technical field of heat treatment, and particularly relates to a heat treatment method for improving carburization internal oxidation of a metal part.
Background
The metal parts are basic structures and performance parts of machinery in the mechanical industry, and are required to have higher surface hardness, wear resistance, higher core strength and toughness and bear certain alternating stress, so that the metal parts need to be subjected to heat treatment in a specific process flow to have the properties of high surface hardness, high wear resistance, fatigue resistance, high dimensional accuracy and the like.
Carburizing and quenching are common heat treatment processes for metal parts, and can ensure that the surface of a part subjected to carburizing obtains high hardness and improve the wear resistance of the part. Currently, the existing carburizing and quenching process generally comprises the following steps: the method comprises the following steps of heating and carburizing in a carburizing furnace, cooling after discharging, cleaning, low-temperature tempering, discharging and cooling, and the like, but the conventional carburizing and quenching process has the disadvantages of too simple furnace feeding, temperature reduction and heating process, too high carburizing temperature and longer treatment time, so that the oxidation quality in the surface of the treated metal part is deteriorated, a finish machining process is required to be additionally added, and the treatment time is greatly prolonged. Therefore, how to develop a heat treatment method which is simple and convenient to operate, consumes short time and can improve the internal oxidation of the surface of the metal part is the key to solve the problems.
Disclosure of Invention
The invention provides a heat treatment method which is simple and convenient to operate, consumes less time and can improve the oxidation quality in the surface of a metal part, aiming at the technical problems that the prior heat treatment method of the metal part has too simple furnace entering cooling and heating processes, overhigh carburizing temperature and longer treatment time, and further causes the deterioration of the oxidation quality in the surface of the treated metal part.
In order to achieve the purpose, the invention adopts the technical scheme that:
a heat treatment method for improving carburization internal oxidation of a metal part comprises the following steps:
setting the initial furnace temperature at 850-950 ℃, starting cooling treatment after the metal parts enter a carburizing furnace, and introducing rich gas and methanol;
heating the metal parts subjected to cooling treatment;
carrying out high-temperature carburization and strong-infiltration treatment and high-temperature carburization and diffusion treatment on the metal part subjected to temperature rise treatment at the temperature of 850-950 ℃;
cooling the metal parts subjected to high-temperature carburization diffusion treatment to 800-900 ℃ along with the furnace, then carrying out uniform heat treatment, and then discharging the metal parts out of the furnace;
the metal parts after soaking treatment are put into oil for quenching, and the quenched metal parts are cleaned by cleaning fluid;
transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, and then discharging from the furnace for air cooling;
and introducing richening gas and methanol in the whole process of the high-temperature carburizing and strong-permeating treatment, the high-temperature carburizing and diffusing treatment and the soaking treatment.
Preferably, the temperature reduction treatment specifically comprises: when the temperature reduction treatment is started, introducing the mixture into the furnace in a mode that the flow rate of the enriched gas is 10-20L/min and the flow rate of the methanol is 45-60mL/min, stopping introducing the enriched gas after 10-20min, and continuously introducing the methanol into the furnace at the flow rate of 45-60 mL/min.
Preferably, the temperature raising treatment specifically includes: after the temperature reduction treatment is finished, continuously introducing methanol into the furnace at the flow rate of 45-60mL/min, then raising the temperature of the furnace to 800-850 ℃, introducing the enriched gas into the furnace at the flow rate of 2-5L/min to form a carburizing atmosphere, and controlling the carbon potential to be 0.70-0.85%;
and in the process of temperature rise treatment, methanol is introduced at the flow rate of 45-60mL/min in the whole process.
Preferably, the carbon potential of the high-temperature carburizing and strong carburizing treatment is 1.0-1.2%, the carburizing time is 80-210min, the carbon potential of the high-temperature carburizing and diffusion treatment is 0.70-0.85%, and the carburizing time is 80-210 min.
Preferably, the initial flow rate of the enriched gas in the high-temperature carburizing and strong carburizing treatment process is 5-10L/min, after the carbon potential is stabilized for 20-30min, the flow rate of the enriched gas is reduced to 3-5L/min, and the flow rate of the methanol is kept at 45-60mL/min all the time.
Preferably, the initial flow rate of the enriched gas in the high-temperature carburization diffusion treatment process is 3-6L/min, after the carbon potential is stabilized for 20-30min, the flow rate of the enriched gas is reduced to 2-4L/min, and the flow rate of the methanol is kept at 45-60mL/min all the time.
Preferably, the flow rate of the enriching gas in the soaking treatment process is 3-6L/min, the flow rate of the methanol is 45-60mL/min, and the soaking treatment time is 30-90 min.
Preferably, the oil temperature of the oil quenching is 60-150 ℃, the temperature of the cleaning solution is 55-90 ℃, the condition of the low-temperature tempering treatment is 150-.
Preferably, during the temperature rising treatment, the high-temperature carburizing and diffusing treatment, the furnace temperature reduction and the homogenizing heat treatment, balanced air is not introduced in the whole process.
Preferably, the enriching gas is selected from any one of methane, propane, kerosene, acetone, and propylene.
Compared with the prior art, the invention has the advantages and positive effects that:
1. the invention provides a heat treatment method for improving carburization internal oxidation of metal parts, which improves the conventional furnace entering cooling and heating procedures, and introduces rich gas into the furnace on the basis of cooling and heating treatment of the metal parts, and can consume residual oxygen in oxidizing atmosphere entering the carburizing furnace along with the metal parts due to the permeation of the rich atmosphere or elements and the strong reducibility of the rich atmosphere or elements so as to reduce the degree and depth of internal oxidation of trace residual oxygen in the atmosphere on the surface of a product;
2. the invention provides a heat treatment method for improving carburization internal oxidation of metal parts, which is characterized in that enriched gas is introduced into a carburizing furnace to form a carburization atmosphere in the processes of temperature reduction and temperature rise, and the carbon potential is set to be 0.70-0.85%, so that the carbon potential in the furnace is further increased in the temperature rise treatment stage, the oxygen potential in the furnace atmosphere is reduced, and the degree and depth of internal oxidation of trace residual oxygen in the atmosphere on the surface of a product are reduced;
3. the invention provides a heat treatment method for improving carburization internal oxidation of metal parts, which keeps a balance air channel closed in the steps of heating treatment, high-temperature carburization diffusion treatment, furnace temperature reduction and soaking treatment, does not introduce balance air into a furnace, can prevent oxygen in the balance air from entering the furnace again, and also reduces the degree and depth of internal oxidation of trace residual oxygen in the atmosphere on the surface of a product.
Drawings
FIG. 1 is a flow chart of a thermal treatment process provided by an embodiment of the present invention;
FIG. 2 is a diagram of an oxidized gold phase in the surface of a metal part according to example 1;
FIG. 3 is a diagram of an oxidized gold phase in the surface of a metal part according to example 2;
FIG. 4 is a diagram of an oxidized gold phase in the surface of a metal part according to example 3 provided in the present invention;
FIG. 5 is a phase diagram of gold oxide in the surface of a metal part according to comparative example 1.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention provides a heat treatment method for improving carburization internal oxidation of a metal part, which comprises the following steps:
s1, setting the initial furnace temperature to 850-950 ℃, starting temperature reduction treatment after the metal parts enter a carburizing furnace, and introducing rich gas and methanol;
in the step S1, after the metal part enters the carburizing furnace, the temperature of the metal part is reduced, and meanwhile, the enriching gas is introduced into the furnace, so that residual oxygen in the oxidizing atmosphere entering the carburizing furnace along with the metal part can be consumed due to the infiltration of the enriching atmosphere or elements and the strong reducibility of the metal part, and the degree and depth of internal oxidation of the product surface caused by trace residual oxygen in the atmosphere can be reduced.
S2, heating the metal parts after cooling treatment;
in the step S2, in the temperature raising process, the enriched gas is introduced into the furnace to form the carburizing atmosphere, and the carbon potential is set to 0.70-0.85%, so that the carbon potential in the furnace is further increased in the temperature raising process, thereby reducing the oxygen potential in the furnace atmosphere and reducing the degree and depth of internal oxidation of the product surface caused by trace residual oxygen in the atmosphere.
S3, carrying out high-temperature carburization and strong-infiltration treatment and high-temperature carburization and diffusion treatment on the metal part subjected to temperature rise treatment at the temperature of 850-950 ℃;
in the step S3, the high temperature carburizing and strongly carburizing treatment and the high temperature carburizing and diffusing treatment are both performed at the temperature of 850-.
S4, cooling the metal parts subjected to the high-temperature carburization diffusion treatment to 800-900 ℃ along with the furnace, then carrying out uniform heat treatment, and then discharging the metal parts out of the furnace;
in the step S4, the temperature decreased with the furnace temperature may be 800 ℃, 810 ℃, 820 ℃, 830 ℃, 840 ℃, 850 ℃, 860 ℃, 870 ℃, 880 ℃, 890 ℃, 900 ℃ or any value selected from the above-mentioned limited range according to actual needs, and all fall within the protection scope of the present invention.
S5, putting the metal parts subjected to soaking treatment into oil for quenching, and cleaning the quenched metal parts by using a cleaning solution;
s6, transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, and discharging and air cooling;
and introducing richening gas and methanol in the whole process of the high-temperature carburizing and strong-permeating treatment, the high-temperature carburizing and diffusing treatment and the soaking treatment.
In a preferred embodiment, the cooling process specifically includes: when the temperature reduction treatment is started, introducing the mixture into the furnace in a mode that the flow rate of the enriched gas is 10-20L/min and the flow rate of the methanol is 45-60mL/min, stopping introducing the enriched gas after 10-20min, and continuously introducing the methanol into the furnace at the flow rate of 45-60 mL/min.
In the preferred embodiment, the flow rate of the enriched gas may be selected from 10L/min, 15L/min, 20L/min or any value within the above-mentioned range as required, and the flow rate of the methanol may be selected from 45mL/min, 50mL/min, 55mL/min, 60mL/min or any value within the above-mentioned range as required.
In a preferred embodiment, the temperature raising process specifically includes: after the temperature reduction treatment is finished, continuously introducing methanol into the furnace at the flow rate of 45-60mL/min, then raising the temperature of the furnace to 800-850 ℃, introducing the enriched gas into the furnace at the flow rate of 2-5L/min to form a carburizing atmosphere, and controlling the carbon potential to be 0.70-0.85%;
and in the process of temperature rise treatment, methanol is introduced at the flow rate of 45-60mL/min in the whole process.
In the preferred embodiment, the flow rate of methanol can be selected from 45mL/min, 50mL/min, 55mL/min, 60mL/min or any value within the above-mentioned limited range according to actual needs, and the flow rate falls within the protection scope of the present invention; the furnace temperature can be selected from 800 ℃, 810 ℃, 820 ℃, 830 ℃, 840 ℃ and 850 ℃ or any value in the limit range selected according to actual needs falls into the protection range of the invention; the flow rate of the enriching gas can be selected from 2L/min, 3L/min, 4L/min and 5L/min or any value within the above limited range according to actual needs, and the carbon potential can be controlled to be 0.70%, 0.75%, 0.80% and 0.85% or any value within the above limited range according to actual needs, and the carbon potential can be within the protection range of the invention.
In a preferred embodiment, the carbon potential of the high-temperature carburizing and strong carburizing treatment is 1.0% -1.2%, the carburizing time is 80-210min, the carbon potential of the high-temperature carburizing and strong carburizing treatment is 0.70% -0.85%, and the carburizing time is 80-210 min.
In the above preferred embodiment, the carbon potential of the high-temperature carburizing and carburizing treatment may be selected from 1.0%, 1.05%, 1.10%, 1.15%, 1.2% or any value selected from the above-mentioned limited range according to actual needs and fall within the protection range of the present invention, the carbon potential of the high-temperature carburizing and diffusing treatment may be selected from 0.70%, 0.75%, 0.80%, 0.85% or any value selected from the above-mentioned limited range according to actual needs and fall within the protection range of the present invention, and the carburizing time of the high-temperature carburizing and carburizing treatment and the diffusion treatment may be selected from 80min, 90min, 100min, 150min, 200min, 210min or any value selected from the above-mentioned limited range according to actual needs and fall within the protection range of the present invention.
In a preferred embodiment, the initial flow rate of the enriched gas in the high-temperature carburizing and strong carburizing treatment process is 5-10L/min, after the carbon potential is stabilized for 20-30min, the flow rate of the enriched gas is reduced to 3-5L/min, and the flow rate of the methanol is kept at 45-60mL/min all the time.
In the preferred embodiment, the initial flow rate of the enriching gas in the high-temperature carburization and strong cementation treatment can be selected from 5L/min, 6L/min, 7L/min, 8L/min, 9L/min and 10L/min or any value within the above-mentioned limited range according to actual needs and fall within the protection range of the invention, and the flow rate of the methanol can be selected from 45mL/min, 50mL/min, 55mL/min, 60mL/min or any value within the above-mentioned limited range according to actual needs and fall within the protection range of the invention.
In a preferred embodiment, the initial flow rate of the enriched gas in the high-temperature carburization diffusion treatment process is 3-6L/min, after the carbon potential is stabilized for 20-30min, the flow rate of the enriched gas is reduced to 2-4L/min, and the flow rate of the methanol is kept at 45-60mL/min all the time.
In the preferred embodiment, the initial flow rate of the enriching gas in the high-temperature carburization diffusion treatment can be selected from 3L/min, 4L/min, 5L/min and 6L/min or any value within the above-mentioned limited range according to actual needs and falls within the protection range of the invention, and the flow rate of the methanol can be selected from 45mL/min, 50mL/min, 55mL/min and 60mL/min or any value within the above-mentioned limited range according to actual needs and falls within the protection range of the invention.
In a preferred embodiment, the flow rate of the enriching gas during the soaking treatment is 3-6L/min, the flow rate can be 3L/min, 4L/min, 5L/min, 6L/min or any value in the limited range according to the actual requirement, and the flow rate of the methanol is 45-60mL/min, the flow rate can be selected from 45mL/min, 50mL/min, 55mL/min, 60mL/min or any value in the limited range according to actual needs, and the flow rate falls within the protection range of the invention, the soaking time is 30-90min, the time can be selected from 30min, 40min, 50min, 60min, 70min, 80min and 90min or any value within the above limited range according to actual needs, and the time falls within the protection range of the invention.
In a preferred embodiment, the oil temperature of the oil quenching is 60-150 ℃, the oil temperature can be selected from 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃ or any value selected from the above limited range according to actual needs to fall within the protection range of the invention, the temperature of the cleaning solution is 55-90 ℃, the temperature can be selected from 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃ or any value selected from the above limited range according to actual needs to fall within the protection range of the invention, the condition of the low-temperature tempering treatment is 150-220 ℃, the temperature can be selected from 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃, 210 ℃, 220 ℃ or any value selected from the above limited range according to actual needs to fall within the protection range of the invention, the temperature is kept for 100-500min, and the temperature keeping time can be selected from 100min, 120min, 200min, 300min, 400min, 480min, 500min or any value within the above-mentioned limited range according to actual needs, which falls within the protection scope of the invention.
In a preferred embodiment, during the temperature-raising treatment, the high-temperature carburizing and diffusing treatment, the temperature reduction along with the furnace and the soaking treatment, balanced air is not introduced in the whole process, so that oxygen in the balanced air can be prevented from entering the furnace again, and the degree and depth of internal oxidation of the surface of the product caused by trace residual oxygen in the atmosphere can be reduced.
In a preferred embodiment, the enriching gas is selected from any one of methane, propane, kerosene, acetone or propylene.
In order to more clearly and specifically describe the heat treatment method for improving the carburized internal oxidation of a metal part provided by the embodiments of the present invention, the following description will be given with reference to specific embodiments.
Comparative example 1
The comparative example provides a heat treatment method of a conventional metal part, which specifically comprises the following steps:
(1) and (3) furnace entering cooling treatment: setting the initial furnace temperature to 850 ℃, and starting cooling treatment after the metal parts enter a carburizing furnace;
(2) entering a furnace for heating treatment: heating the metal parts subjected to cooling treatment, and heating the furnace to 800 ℃;
(3) high-temperature carburizing and strong carburizing treatment and high-temperature carburizing and diffusing treatment: the metal parts after temperature rise treatment are subjected to high-temperature carburization and strong-permeability treatment and high-temperature carburization and diffusion treatment at 850 ℃, wherein the conditions of the high-temperature carburization and strong-permeability treatment are as follows: controlling the carbon potential to be 1.0 percent and the carburizing time to be 80min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 5L/min, reducing the flow rate of the propane to 3L/min after the carbon potential is stabilized for 20min, and keeping the flow rate of the methanol at 45mL/min all the time;
the conditions of the high-temperature carburization diffusion treatment are as follows: controlling the carbon potential to be 0.70 percent, controlling the carburizing time to be 80min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 3L/min, reducing the flow rate of the propane to 2L/min after the carbon potential is stabilized for 20min, and keeping the flow rate of the methanol at 45mL/min all the time;
(4) furnace cooling and soaking treatment: cooling the metal parts subjected to high-temperature carburization and diffusion treatment to 800 ℃ along with a furnace, then carrying out uniform heat treatment, introducing propane and methanol into the furnace in the uniform heat treatment process, wherein the flow rate of the propane is 3L/min, the flow rate of the methanol is 45mL/min, the uniform heat treatment time is 30min, and then discharging the metal parts out of the furnace;
(5) quenching and cleaning: the metal parts after soaking treatment are put into oil for quenching, the oil temperature for quenching is 60 ℃, and 55 ℃ cleaning fluid is used for cleaning the quenched metal parts;
(6) low-temperature tempering and air cooling: and (3) transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, keeping the temperature for 100min under the low-temperature tempering treatment condition of 150 ℃, discharging and air cooling to finish the heat treatment process of the metal parts.
Example 1
The embodiment provides a heat treatment method for improving carburization internal oxidation of a metal part, which specifically comprises the following steps:
(1) and (3) furnace entering cooling treatment: setting the initial furnace temperature to be 850 ℃, starting cooling treatment after metal parts enter a carburizing furnace, introducing the metal parts into the furnace in a mode that the propane flow rate is 20L/min and the methanol flow rate is 45mL/min when the cooling is started, stopping introducing the metal parts after 10min of introducing the propane, and continuously introducing the methanol into the furnace at the flow rate of 45 mL/min;
(2) entering a furnace for heating treatment: heating the metal parts subjected to temperature reduction treatment, specifically, after the temperature reduction treatment in the step (1) is finished, continuously introducing methanol into the furnace at a flow rate of 45mL/min, then heating the furnace to 800 ℃, introducing the methanol into the furnace at a flow rate of 2L/min propane to form a carburizing atmosphere, and controlling the carbon potential to be 0.70%, wherein in the treatment process in the step, the methanol is introduced at a flow rate of 45mL/min in the whole process;
(3) high-temperature carburizing and strong carburizing treatment and high-temperature carburizing and diffusing treatment: the metal parts after temperature rise treatment are subjected to high-temperature carburization and strong-permeability treatment and high-temperature carburization and diffusion treatment at 850 ℃, wherein the conditions of the high-temperature carburization and strong-permeability treatment are as follows: controlling the carbon potential to be 1.0 percent and the carburizing time to be 80min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 5L/min, reducing the flow rate of the propane to 3L/min after the carbon potential is stabilized for 20min, and keeping the flow rate of the methanol at 45mL/min all the time;
the conditions of the high-temperature carburization diffusion treatment are as follows: controlling the carbon potential to be 0.70 percent, controlling the carburizing time to be 80min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 3L/min, reducing the flow rate of the propane to 2L/min after the carbon potential is stabilized for 20min, and keeping the flow rate of the methanol at 45mL/min all the time;
(4) furnace cooling and soaking treatment: cooling the metal parts subjected to high-temperature carburization and diffusion treatment to 800 ℃ along with a furnace, then carrying out uniform heat treatment, introducing propane and methanol into the furnace in the uniform heat treatment process, wherein the flow rate of the propane is 3L/min, the flow rate of the methanol is 45mL/min, the uniform heat treatment time is 30min, and then discharging the metal parts out of the furnace;
in the processes of heating treatment, high-temperature carburizing and diffusing treatment, furnace temperature reduction and uniform heat treatment, balanced air is not introduced in the whole process;
(5) quenching and cleaning: the metal parts after soaking treatment are put into oil for quenching, the oil temperature for quenching is 60 ℃, and 55 ℃ cleaning fluid is used for cleaning the quenched metal parts;
(6) low-temperature tempering and air cooling: and (3) transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, keeping the temperature for 100min under the low-temperature tempering treatment condition of 150 ℃, discharging and air cooling to finish the heat treatment process of the metal parts.
Example 2
The embodiment provides a heat treatment method for improving carburization internal oxidation of a metal part, which specifically comprises the following steps:
(1) and (3) furnace entering cooling treatment: setting the initial furnace temperature to 950 ℃, starting cooling treatment after metal parts enter a carburizing furnace, introducing into the furnace in a mode that the propane flow rate is 10L/min and the methanol flow rate is 60mL/min when cooling is started, stopping introducing after propane is introduced for 20min, and continuously introducing the methanol into the furnace at the flow rate of 60 mL/min;
(2) entering a furnace for heating treatment: heating the metal parts subjected to temperature reduction treatment, specifically, after the temperature reduction treatment in the step (1) is finished, continuously introducing methanol into the furnace at a flow rate of 60mL/min, then heating the furnace to 850 ℃, introducing the methanol into the furnace at a flow rate of 5L/min propane to form a carburizing atmosphere, controlling the carbon potential to be 0.85%, and introducing the methanol at a flow rate of 60mL/min in the whole treatment process in the step;
(3) high-temperature carburizing and strong carburizing treatment and high-temperature carburizing and diffusing treatment: the metal parts after the temperature rise treatment are subjected to high-temperature carburization and strong-permeability treatment and high-temperature carburization and diffusion treatment at 950 ℃, wherein the conditions of the high-temperature carburization and strong-permeability treatment are as follows: controlling the carbon potential to be 1.5 percent, controlling the carburizing time to be 210min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 10L/min, reducing the flow rate of the propane to 3L/min after the carbon potential is stabilized for 30min, and keeping the flow rate of the methanol at 60mL/min all the time;
the conditions of the high-temperature carburization diffusion treatment are as follows: controlling the carbon potential to be 0.85 percent, controlling the carburizing time to be 210min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 6L/min, reducing the flow rate of the propane to 2L/min after the carbon potential is stabilized for 30min, and keeping the flow rate of the methanol to be 60mL/min all the time;
(4) furnace cooling and soaking treatment: cooling the metal parts subjected to high-temperature carburization and diffusion treatment to 900 ℃ along with a furnace, then carrying out uniform heat treatment, introducing propane and methanol into the furnace in the uniform heat treatment process, wherein the flow rate of the propane is 6L/min, the flow rate of the methanol is 60mL/min, the uniform heat treatment time is 90min, and then discharging the metal parts out of the furnace;
in the processes of heating treatment, high-temperature carburizing and diffusing treatment, furnace temperature reduction and uniform heat treatment, balanced air is not introduced in the whole process;
(5) quenching and cleaning: the metal parts after soaking treatment are put into oil for quenching, the oil temperature for quenching is 150 ℃, and the quenched metal parts are cleaned by cleaning fluid at 90 ℃;
(6) low-temperature tempering and air cooling: and (3) transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, keeping the temperature for 480min under the low-temperature tempering treatment condition of 220 ℃, discharging and air cooling to finish the heat treatment process of the metal parts.
Example 3
The embodiment provides a heat treatment method for improving carburization internal oxidation of a metal part, which specifically comprises the following steps:
(1) and (3) furnace entering cooling treatment: setting the initial furnace temperature to be 920 ℃, starting cooling treatment after metal parts enter a carburizing furnace, introducing the metal parts into the furnace in a mode that the propane flow rate is 15L/min and the methanol flow rate is 50mL/min when the cooling is started, stopping introducing the metal parts after the propane is introduced for 15min, and continuously introducing the metal parts into the furnace while keeping the methanol flow rate of 50 mL/min;
(2) entering a furnace for heating treatment: heating the metal parts subjected to temperature reduction treatment, specifically, after the temperature reduction treatment in the step (1) is finished, continuously introducing methanol into the furnace at a flow rate of 50mL/min, then heating the furnace to 820 ℃, introducing the methanol into the furnace at a flow rate of 4L/min propane to form a carburizing atmosphere, controlling the carbon potential to be 0.80%, and introducing the methanol at a flow rate of 50mL/min in the whole treatment process in the step;
(3) high-temperature carburizing and strong carburizing treatment and high-temperature carburizing and diffusing treatment: the metal parts after the temperature rise treatment are subjected to high-temperature carburization and strong-permeability treatment and high-temperature carburization and diffusion treatment at the temperature of 900 ℃, wherein the conditions of the high-temperature carburization and strong-permeability treatment are as follows: controlling the carbon potential to be 1.2 percent, controlling the carburizing time to be 150min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 8L/min, reducing the flow rate of the propane to 3L/min after the carbon potential is stabilized for 25min, and keeping the flow rate of the methanol at 50mL/min all the time;
the conditions of the high-temperature carburization diffusion treatment are as follows: controlling the carbon potential to be 0.80%, controlling the carburizing time to be 150min, introducing propane and methanol into the furnace, wherein the initial flow rate of the propane is 5L/min, reducing the flow rate of the propane to 2L/min after the carbon potential is stabilized for 25min, and keeping the flow rate of the methanol at 50mL/min all the time;
(4) furnace cooling and soaking treatment: cooling the metal parts subjected to high-temperature carburization and diffusion treatment to 850 ℃ along with a furnace, then carrying out uniform heat treatment, introducing propane and methanol into the furnace in the uniform heat treatment process, wherein the flow rate of the propane is 5L/min, the flow rate of the methanol is 50mL/min, the uniform heat treatment time is 60min, and then discharging the metal parts out of the furnace;
in the processes of heating treatment, high-temperature carburizing and diffusing treatment, furnace temperature reduction and uniform heat treatment, balanced air is not introduced in the whole process;
(5) quenching and cleaning: the metal parts after soaking treatment are put into oil for quenching, the oil temperature for quenching is 90 ℃, and the quenched metal parts are cleaned by cleaning fluid at the temperature of 75 ℃;
(6) low-temperature tempering and air cooling: and (3) transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, keeping the temperature for 280min under the low-temperature tempering treatment condition of 180 ℃, discharging and air cooling to finish the heat treatment process of the metal parts.
Performance testing
The invention also carries out the performance tests such as internal oxidation depth and the like on the metal parts obtained by the heat treatment method, and the specific test method and the result are as follows:
(1) the test method comprises the following steps: and observing the oxidation depth in the surface of the metal part by using a metallographic microscope at a time of 100 times.
(2) And (3) testing results:
TABLE 1 statistics of the performance test results of the treated metal parts of the examples and comparative examples
| Test method | Depth of internal oxidation (. mu.m) | |
| Example 1 | Observing the oxidation depth in the surface by 100 times using a metallographic microscope | ≤25μm |
| Example 2 | Observing the oxidation depth in the surface by 100 times using a metallographic microscope | ≤25μm |
| Example 3 | Observing the oxidation depth in the surface by 100 times using a metallographic microscope | ≤25μm |
| Comparative example 1 | Observing the oxidation depth in the surface by 100 times using a metallographic microscope | 37-40μm |
As can be seen from the above experimental results in conjunction with FIGS. 2 to 5, the heat treatment method described in comparative example 1 for treating metal parts still has the problem of deterioration of oxidation quality in the surface, in the embodiments 1-3 of the invention, the conventional processes of furnace entering, temperature reduction and temperature rise are improved, on the basis of cooling and heating the metal parts, introducing enriching gas into the furnace to consume residual oxygen in the oxidizing atmosphere entering the carburizing furnace along with the metal parts so as to reduce the degree and depth of internal oxidation of the surface of the product caused by trace residual oxygen in the atmosphere, and the rich gas is introduced to form carburizing atmosphere, so that the carbon potential in the furnace is further improved in the stage of temperature rise treatment, thereby reducing the oxygen potential in the furnace atmosphere, reducing the degree and depth of internal oxidation of the product surface caused by trace residual oxygen in the atmosphere, and thoroughly solving the problem of the deterioration of the internal oxidation quality of the surface of the metal part after heat treatment.
Claims (10)
1. A heat treatment method for improving carburization internal oxidation of a metal part is characterized by comprising the following steps:
setting the initial furnace temperature at 850-950 ℃, starting cooling treatment after the metal parts enter a carburizing furnace, and introducing rich gas and methanol;
heating the metal parts subjected to cooling treatment;
carrying out high-temperature carburization and strong-infiltration treatment and high-temperature carburization and diffusion treatment on the metal part subjected to temperature rise treatment at the temperature of 850-950 ℃;
cooling the metal parts subjected to high-temperature carburization diffusion treatment to 800-900 ℃ along with the furnace, then carrying out uniform heat treatment, and then discharging the metal parts out of the furnace;
the metal parts after soaking treatment are put into oil for quenching, and the quenched metal parts are cleaned by cleaning fluid;
transferring the cleaned metal parts into a tempering furnace for low-temperature tempering treatment, and then discharging from the furnace for air cooling;
and introducing richening gas and methanol in the whole process of the high-temperature carburizing and strong-permeating treatment, the high-temperature carburizing and diffusing treatment and the soaking treatment.
2. The heat treatment method for improving carburized internal oxidation of a metal part according to claim 1, wherein the temperature reduction treatment is specifically: when the temperature reduction treatment is started, introducing the mixture into the furnace in a mode that the flow rate of the enriched gas is 10-20L/min and the flow rate of the methanol is 45-60mL/min, stopping introducing the enriched gas after 10-20min, and continuously introducing the methanol into the furnace at the flow rate of 45-60 mL/min.
3. The heat treatment method for improving carburized internal oxidation of a metal part according to claim 1, wherein the temperature raising treatment is specifically: after the temperature reduction treatment is finished, continuously introducing methanol into the furnace at the flow rate of 45-60mL/min, then raising the temperature of the furnace to 800-850 ℃, introducing the enriched gas into the furnace at the flow rate of 2-5L/min to form a carburizing atmosphere, and controlling the carbon potential to be 0.70-0.85%;
and in the process of temperature rise treatment, methanol is introduced at the flow rate of 45-60mL/min in the whole process.
4. The heat treatment method for improving carburization internal oxidation of metal parts according to claim 1, wherein the carbon potential of the high-temperature carburization and strong carburization treatment is 1.0% to 1.2%, the carburization time is 80 to 210min, the carbon potential of the high-temperature carburization and diffusion treatment is 0.70% to 0.85%, and the carburization time is 80 to 210 min.
5. The heat treatment method for improving the carburization internal oxidation of the metal part according to claim 1, wherein the initial flow rate of the enriched gas in the high-temperature carburization and strong carburization treatment process is 5 to 10L/min, after the carbon potential is stabilized for 20 to 30min, the flow rate of the enriched gas is reduced to 3 to 5L/min, and the flow rate of the methanol is kept at 45 to 60mL/min all the time.
6. The heat treatment method for improving the carburization internal oxidation of the metal part according to claim 1, wherein the initial flow rate of the enriched gas in the high-temperature carburization diffusion treatment process is 3 to 6L/min, after the carbon potential is stabilized for 20 to 30min, the flow rate of the enriched gas is reduced to 2 to 4L/min, and the flow rate of the methanol is kept at 45 to 60mL/min all the time.
7. The heat treatment method for improving carburization internal oxidation of metal parts according to claim 1, wherein the flow rate of the rich gas during the soaking treatment is 3 to 6L/min, the flow rate of methanol is 45 to 60mL/min, and the soaking treatment time is 30 to 90 min.
8. The heat treatment method for improving the carburization internal oxidation of the metal part as claimed in claim 1, wherein the oil temperature for the oil quenching is 60-150 ℃, the temperature of the cleaning solution is 55-90 ℃, the conditions for the low temperature tempering treatment are 150-220 ℃, and the temperature is maintained for 100-500 min.
9. The heat treatment method for improving carburized internal oxidation of metal parts according to claim 1, wherein no balance air is introduced during the whole of said temperature-raising treatment, high-temperature carburization diffusion treatment, furnace temperature-lowering treatment and soaking treatment.
10. The heat treatment method for improving carburization internal oxidation of metal parts according to claim 1, wherein the enriching gas is any one selected from methane, propane, kerosene, acetone, and propylene.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113755788A (en) * | 2021-08-30 | 2021-12-07 | 潍坊丰东热处理有限公司 | Heat treatment method for improving carbon black accumulated on surface of carburized metal part |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100276036A1 (en) * | 2006-02-22 | 2010-11-04 | General Electric Company | Carburization process for stabilizing nickel-based superalloys |
| CN105648393A (en) * | 2014-12-03 | 2016-06-08 | 重庆业高家具有限公司 | Surface carburizing process for mold |
| CN106086771A (en) * | 2016-08-10 | 2016-11-09 | 奇瑞汽车股份有限公司 | Gas carburizing Technology for Heating Processing for gasoline engine timing chain bar bearing pin |
| CN109097533A (en) * | 2018-10-25 | 2018-12-28 | 汉德车桥(株洲)齿轮有限公司 | A kind of heat treatment method of middle large module gear |
-
2021
- 2021-04-07 CN CN202110371279.4A patent/CN113106377A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100276036A1 (en) * | 2006-02-22 | 2010-11-04 | General Electric Company | Carburization process for stabilizing nickel-based superalloys |
| CN105648393A (en) * | 2014-12-03 | 2016-06-08 | 重庆业高家具有限公司 | Surface carburizing process for mold |
| CN106086771A (en) * | 2016-08-10 | 2016-11-09 | 奇瑞汽车股份有限公司 | Gas carburizing Technology for Heating Processing for gasoline engine timing chain bar bearing pin |
| CN109097533A (en) * | 2018-10-25 | 2018-12-28 | 汉德车桥(株洲)齿轮有限公司 | A kind of heat treatment method of middle large module gear |
Non-Patent Citations (1)
| Title |
|---|
| 王有铭等: "17Cr2Ni2MoA大齿轮渗碳中发生内氧化原因和预防", 《机械工程师》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113755788A (en) * | 2021-08-30 | 2021-12-07 | 潍坊丰东热处理有限公司 | Heat treatment method for improving carbon black accumulated on surface of carburized metal part |
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