CN112593183A - Heat treatment method for carburizing and quenching - Google Patents
Heat treatment method for carburizing and quenching Download PDFInfo
- Publication number
- CN112593183A CN112593183A CN202011152592.0A CN202011152592A CN112593183A CN 112593183 A CN112593183 A CN 112593183A CN 202011152592 A CN202011152592 A CN 202011152592A CN 112593183 A CN112593183 A CN 112593183A
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- Prior art keywords
- carburizing
- quenching
- workpiece
- section treatment
- temperature
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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
- C23C8/22—Carburising of ferrous surfaces
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- 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
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- 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
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- 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
- C21D11/00—Process control or regulation for heat treatments
- C21D11/005—Process control or regulation for heat treatments for cooling
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/001—Austenite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Abstract
The invention discloses a heat treatment method for carburizing and quenching, which is applied to the gas carburizing and quenching production normally required by common low-carbon steel and low-carbon alloy steel workpieces and specifically comprises the following steps: s1, firstly, loading the workpiece into a carburizing furnace, and carrying out strong-permeation section treatment and diffusion section treatment on the workpiece in the carburizing furnace; the carburizing temperature of the strong carburizing section treatment is 915-925 ℃, and the carbon potential of the strong carburizing section treatment is 1.1-1.2%; the carburization temperature of the diffusion section treatment is 905-915 ℃, and the carbon potential of the diffusion section treatment is 0.8-0.9%; the proportion of the carburizing and heat-preserving time of the strong-permeation section treatment and the diffusion section treatment is 11: 9; s2, cooling and quenching along with a carburizing furnace; s3, cooling by quenching oil; s4, tempering; the invention not only ensures the hardness and hardened layer depth of the low-carbon alloy steel workpiece, but also ensures that the refined metallographic structure meets the national standard, and stably improves the carburizing and quenching quality.
Description
The technical field is as follows:
the invention relates to the technical field of processing of common low-carbon steel and low-carbon alloy steel workpieces, in particular to a heat treatment method for carburizing and quenching.
Background art:
the carburizing and quenching of steel is a common chemical heat treatment process, a low-carbon steel and low-carbon alloy steel workpiece is heated and insulated in a carburizing medium, so that carbon atoms penetrate into the surface of the workpiece and a carburized layer with a certain depth is obtained, and then quenching and low-temperature tempering are carried out, so that the surface layer of the workpiece obtains a high-carbon martensite structure, thereby improving the surface hardness, the wear resistance and the fatigue strength of the workpiece, and the center of the workpiece keeps the good toughness and the plasticity of the original low-carbon steel.
The traditional carburizing and quenching process of the common carburizing steel mainly comprises two types of cooling direct quenching after carburizing and air cooling after carburizing or slow cooling and reheating quenching after carburizing, and the cooling direct quenching after carburizing can be widely applied in production by the advantages of simple operation, high efficiency and low cost, but the process can not refine crystal grains and tissues coarsened at high carburizing temperature and for a long time, and poor tissues such as coarse martensite and the like often appear in a carburized layer after quenching, so that the mechanical properties such as toughness and the like are reduced, and the use performance requirements of workpieces are difficult to meet.
The invention content is as follows:
it is an object of the present invention to provide a heat treatment method for carburizing and quenching that solves one or more of the above-mentioned problems of the prior art.
In order to solve the technical problems, the invention provides a carburizing and quenching heat treatment method, which is applied to the gas carburizing and quenching production normally required by common low-carbon steel and low-carbon alloy steel workpieces, and has the innovation points that: the method specifically comprises the following steps:
s1, firstly, loading the workpiece into a carburizing furnace, and carrying out strong-permeation section treatment and diffusion section treatment on the workpiece in the carburizing furnace; the carburizing temperature of the strong carburizing section treatment is 915-925 ℃, and the carbon potential of the strong carburizing section treatment is 1.1-1.2%; the carburization temperature of the diffusion section treatment is 905-915 ℃, and the carbon potential of the diffusion section treatment is 0.8-0.9%; the proportion of the carburizing and heat-preserving time of the strong-permeation section treatment and the diffusion section treatment is 11: 9;
s2, cooling and quenching along with a carburizing furnace, keeping the workpiece obtained in the step S1 in the carburizing furnace for 0.4-0.6h at the temperature of 905-915 ℃, and then quenching the workpiece in the carburizing furnace at the temperature of 810-820 ℃;
s3, quenching oil cooling, namely soaking the workpiece obtained in the step S2 in quenching oil for cooling, wherein the oil temperature is 40-80 ℃, and the quenching oil cooling time is 20-30 min;
and S4, tempering, namely tempering the workpiece obtained in the step S3 at a low temperature of 160-200 ℃ for 2-3 h.
Further, in the above step S1, the carburizing atmosphere of propane + methanol + balance air is used, and the carbon potential inside the carburizing furnace is monitored and controlled using a carbon potential oxygen probe.
Further, in step S4, the workpiece is blanked with nitrogen gas during tempering, and is cooled in air after tempering.
The invention has the beneficial effects that:
1. the invention provides a heat treatment method for carburizing and quenching, which can ensure the technical requirement and the carburizing efficiency of a workpiece and prevent the coarse metallographic structure of the workpiece by reasonably setting the carburizing temperature for the strong carburizing section treatment and the diffusion section treatment of the workpiece.
2. The invention provides a heat treatment method for carburizing and quenching, which ensures the technical requirements of workpieces and can prevent the thick metallographic structure of the workpieces by reasonably setting the carburizing carbon potential of the strong-permeation section treatment and the diffusion section treatment of the workpieces.
3. The invention provides a heat treatment method for carburizing and quenching, which can meet the hardness and hardened layer depth of a carburized layer of a low-carbon alloy steel workpiece and the requirements of a metallographic structure by reasonably setting the proportion of carburizing time of a strong carburizing section treatment and a diffusion section treatment of the low-carbon alloy steel workpiece.
4. The invention provides a heat treatment method for carburizing and quenching, which ensures the surface hardness and the refined structure of a low-carbon alloy steel workpiece by reasonably setting the quenching temperature of the low-carbon alloy steel workpiece.
5. The invention provides a heat treatment method for carburizing and quenching, which ensures the depth of a through-hardened layer of a low-carbon alloy steel workpiece and prevents the defects caused by overlarge quenching stress by reasonably setting the quenching oil cooling time and the oil cooling temperature of the low-carbon alloy steel workpiece.
6. The invention provides a heat treatment method for carburizing and quenching, which ensures the requirements of the hardness and the like of a workpiece by reasonably setting the tempering temperature and the tempering time of a low-carbon alloy steel workpiece, eliminates the quenching stress and prevents the workpiece from generating cracks.
The specific implementation mode is as follows:
for the purpose of enhancing understanding of the present invention, the present invention will be further described in detail with reference to the following examples, which are provided for illustration only and are not to be construed as limiting the scope of the present invention.
The invention provides a carburizing and quenching heat treatment method, which is applied to low-carbon alloy workpieces with the bore diameter of less than 50mm and gas carburizing and quenching production normally required by common low-carbon steel and low-carbon alloy steel workpieces, and specifically comprises the following steps:
s1, firstly, loading the workpiece into a carburizing furnace, and carrying out strong-permeation section treatment and diffusion section treatment on the workpiece in the carburizing furnace; the carburizing temperature of the strong carburizing section treatment is 915-925 ℃, and the carbon potential of the strong carburizing section treatment is 1.1-1.2%; the carburization temperature of the diffusion section treatment is 905-915 ℃, and the carbon potential of the diffusion section treatment is 0.8-0.9%; the proportion of the carburizing and heat-preserving time of the strong-permeation section treatment and the diffusion section treatment is 11: 9;
s2, cooling and quenching along with a carburizing furnace, keeping the workpiece obtained in the step S1 in the carburizing furnace for 0.4-0.6h at the temperature of 905-915 ℃, and then quenching the workpiece in the carburizing furnace at the temperature of 810-820 ℃;
s3, quenching oil cooling, namely soaking the workpiece obtained in the step S2 in quenching oil for cooling, wherein the oil temperature is 40-80 ℃, and the quenching oil cooling time is 20-30 min;
and S4, tempering, namely tempering the workpiece obtained in the step S3 at a low temperature of 160-200 ℃ for 2-3 h.
In the present invention, in step S1, the carburizing atmosphere of propane + methanol + balance air is used, and the carbon potential inside the carburizing furnace is monitored and controlled using a carbon potential oxygen probe.
In the present invention, in step S4, the workpiece is blanked with nitrogen gas during tempering, and is cooled in air after tempering.
Example 1
The heat treatment method for carburizing and quenching provided by the invention has the following specific parameters of the transmission shaft, surface hardness: 55-60HRC, effective hardening depth: 0.8-1.2mm, infiltration layer: martensite + retained austenite is 1-4 grade, carbide is 1-3 grade, and martensite + bainite + ferrite is 1-4 grade in the core.
Example 2
By taking a bearing as an example, the heat treatment method for carburizing and quenching provided by the invention has the following specific parameters of the bearing, namely the surface hardness: 58-62HRC, effective depth of hardened layer: 0.6-1.0mm, infiltration layer: martensite + retained austenite is of grade 2-4, carbide is of grade 1-2, and martensite + bainite + ferrite is of grade 1-3 in the core.
In the invention, after the carburizing and quenching heat treatment method provided by the invention is adopted in the embodiment 1 and the embodiment 2, all performance indexes of a transmission shaft, a gear and a bearing meet the national standard.
It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (3)
1. A heat treatment method for carburizing and quenching is applied to the gas carburizing and quenching production normally required by common low-carbon steel and low-carbon alloy steel workpieces, and is characterized in that: the method specifically comprises the following steps:
s1, firstly, loading a workpiece into a carburizing furnace, and carrying out strong penetration section treatment and diffusion section treatment on the workpiece in the carburizing furnace; the carburizing temperature of the strong carburizing section treatment is 915-925 ℃, and the carbon potential of the strong carburizing section treatment is 1.1-1.2%; the carburization temperature of the diffusion section treatment is 905-915 ℃, and the carbon potential of the diffusion section treatment is 0.8-0.9%; the carburization heat preservation time ratio of the strong carburization section treatment to the diffusion section treatment is 11: 9;
s2, cooling and quenching along with a carburizing furnace, keeping the workpiece obtained in the step S1 in the carburizing furnace for 0.4-0.6h at the temperature of 905-915 ℃, and then quenching the workpiece in the carburizing furnace at the temperature of 810-820 ℃;
s3, quenching oil cooling, namely soaking the workpiece obtained in the step S2 in quenching oil for cooling, wherein the oil temperature is 40-80 ℃, and the quenching oil cooling time is 20-30 min;
and S4, tempering, namely tempering the workpiece obtained in the step S3 at a low temperature of 160-200 ℃ for 2-3 h.
2. The heat treatment method for carburizing and quenching according to claim 1, characterized in that: in the step S1, the permeation agent atmosphere of propane + methanol + balance air is adopted, and the carbon potential inside the carburizing furnace is monitored and controlled by using a carbon potential oxygen probe.
3. The heat treatment method for carburizing and quenching according to claim 1, characterized in that: in step S4, the workpiece is protected by flushing nitrogen gas during tempering, and is cooled in air after tempering.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011152592.0A CN112593183A (en) | 2020-10-26 | 2020-10-26 | Heat treatment method for carburizing and quenching |
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| CN202011152592.0A CN112593183A (en) | 2020-10-26 | 2020-10-26 | Heat treatment method for carburizing and quenching |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032493A (en) * | 2021-09-28 | 2022-02-11 | 上海热处理厂有限公司 | Method for modifying high hardness of surface of low-carbon alloy steel |
| CN114182194A (en) * | 2022-01-13 | 2022-03-15 | 浙江伟刚自动化设备有限公司 | Universal joint sleeve blank carburizing and quenching heat treatment equipment and treatment process thereof |
| CN114214589A (en) * | 2021-12-17 | 2022-03-22 | 大连长丰实业总公司 | Carburizing method suitable for drop-feed gas carburizing furnace |
| CN114686650A (en) * | 2022-05-06 | 2022-07-01 | 宁夏天地西北煤机有限公司 | Gradient decreasing type deep carburizing process for backstop of large belt conveyor and backstop |
| CN117448733A (en) * | 2023-11-07 | 2024-01-26 | 安徽天瑞精密汽车零部件有限公司 | Heat treatment process for main shaft of large rotary hydraulic motor of excavator |
Citations (5)
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| CN101886165A (en) * | 2010-07-02 | 2010-11-17 | 镇江大力液压马达有限责任公司 | Heat treatment process for low-carbon multi-element alloy steel |
| CN102776471A (en) * | 2012-07-10 | 2012-11-14 | 镇江中船设备有限公司 | Carburizing quenching technology for low-carbon alloy steel parts |
| CN105331888A (en) * | 2015-12-11 | 2016-02-17 | 东北大学 | Regulating method for surface and core part structure of 20CrNi2MoV steel |
| CN108588630A (en) * | 2018-07-19 | 2018-09-28 | 上海上大热处理有限公司 | A kind of carburizing heat treatment method of steering gear gear mechanism |
| CN111719110A (en) * | 2020-06-30 | 2020-09-29 | 江苏南方机电股份有限公司 | Heat treatment process for accurately controlling depth of carburized layer |
-
2020
- 2020-10-26 CN CN202011152592.0A patent/CN112593183A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101886165A (en) * | 2010-07-02 | 2010-11-17 | 镇江大力液压马达有限责任公司 | Heat treatment process for low-carbon multi-element alloy steel |
| CN102776471A (en) * | 2012-07-10 | 2012-11-14 | 镇江中船设备有限公司 | Carburizing quenching technology for low-carbon alloy steel parts |
| CN105331888A (en) * | 2015-12-11 | 2016-02-17 | 东北大学 | Regulating method for surface and core part structure of 20CrNi2MoV steel |
| CN108588630A (en) * | 2018-07-19 | 2018-09-28 | 上海上大热处理有限公司 | A kind of carburizing heat treatment method of steering gear gear mechanism |
| CN111719110A (en) * | 2020-06-30 | 2020-09-29 | 江苏南方机电股份有限公司 | Heat treatment process for accurately controlling depth of carburized layer |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032493A (en) * | 2021-09-28 | 2022-02-11 | 上海热处理厂有限公司 | Method for modifying high hardness of surface of low-carbon alloy steel |
| CN114214589A (en) * | 2021-12-17 | 2022-03-22 | 大连长丰实业总公司 | Carburizing method suitable for drop-feed gas carburizing furnace |
| CN114182194A (en) * | 2022-01-13 | 2022-03-15 | 浙江伟刚自动化设备有限公司 | Universal joint sleeve blank carburizing and quenching heat treatment equipment and treatment process thereof |
| CN114686650A (en) * | 2022-05-06 | 2022-07-01 | 宁夏天地西北煤机有限公司 | Gradient decreasing type deep carburizing process for backstop of large belt conveyor and backstop |
| CN117448733A (en) * | 2023-11-07 | 2024-01-26 | 安徽天瑞精密汽车零部件有限公司 | Heat treatment process for main shaft of large rotary hydraulic motor of excavator |
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Application publication date: 20210402 |