CN111187899A - Gear heat treatment process - Google Patents
Gear heat treatment process Download PDFInfo
- Publication number
- CN111187899A CN111187899A CN201811356286.1A CN201811356286A CN111187899A CN 111187899 A CN111187899 A CN 111187899A CN 201811356286 A CN201811356286 A CN 201811356286A CN 111187899 A CN111187899 A CN 111187899A
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- Prior art keywords
- temperature
- gear
- tempering
- quenching
- treatment process
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/32—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for gear wheels, worm wheels, or the like
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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
-
- 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
- C21D1/26—Methods of annealing
- C21D1/28—Normalising
-
- 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
- C21D1/26—Methods of annealing
- C21D1/30—Stress-relieving
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- 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
Abstract
The invention discloses a gear heat treatment process, which comprises the following steps: step 1, preheating, namely forging a gear blank, and then normalizing, quenching and tempering; step 2, stress is eliminated; step 3, carburizing treatment, wherein a stepped heating-up and heat-preservation heating mode is adopted in a protective atmosphere environment; step 4, tempering, namely firstly tempering at high temperature; quenching again; and (4) low-temperature tempering. The invention has the advantages that: the gear is treated by a preheating treatment process of normalizing, quenching and tempering, and process parameters in the carburizing and quenching process are optimized, so that the distortion of the gear can be greatly reduced, and the distortion of the gear can be reduced by about 30%; the components of the gear are optimized by adding Mn, Cr, Mo, V and rare earth elements, so that the stability of the gear is obviously improved, the hardenability and hardenability of a gear shaft are improved, and the wear resistance and fatigue resistance of the product are improved.
Description
Technical Field
The invention relates to the technical field of gear machining, in particular to a gear heat treatment process.
Background
The distortion problem of gear carburizing and quenching is a worldwide problem, and the economic loss caused by the distortion problem is huge every year. The distortion problem of the carburized and quenched gear has a plurality of influencing factors which are crossed, the main factors change from time to time, and the deformation phenomenon generated by reaction also changes. The carburizing and quenching process and the control of the process parameters in the process have important influence on the distortion of the carburizing and quenching gear.
Since the development is open, in order to meet the requirements of high quality and diversified varieties of products, a large number of advanced gear production lines are newly built and reconstructed in China, and better product performance and service life are expected to be obtained. However, the shaft body surface hardness of the existing gear product is low, the hardening layer is shallow, and the anti-stripping and anti-accident capabilities are weak, so that the use requirements cannot be met. The user urgently requires to improve the depth and the wear resistance of the gear hardening layer, and the gear hardening layer has good anti-fatigue capability so as to prolong the service life and reduce the shaft consumption and the production cost.
The present invention has been advantageously explored and attempted for this purpose, and a solution to the above-mentioned problems has been found, which is the result of the solution described below.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a gear heat treatment process aiming at the defects and shortcomings of the prior art.
The technical problem solved by the invention can be realized by adopting the following technical scheme:
a gear heat treatment process is characterized by comprising the following steps:
step 1, preheating treatment, namely forging a gear blank, normalizing, quenching and tempering, wherein the normalizing temperature is 900-940 ℃, the furnace temperature is less than or equal to 500 ℃, charging is carried out, the temperature is initially increased at 500 ℃, the temperature is increased at the speed of less than or equal to 90 ℃/h, the temperature is kept at 680 ℃, the temperature is kept for 40min at the temperature-keeping time of every 50mm, and then air cooling is carried out; the quenching temperature is 860-880 ℃, the furnace temperature is less than or equal to 500 ℃, the furnace is charged, the temperature is raised initially at 500 ℃, the temperature is raised at the speed of less than or equal to 90 ℃/h, the temperature is kept at 680 ℃, the temperature is kept for 40min per 50mm, and then the oil cooling is carried out; the tempering temperature is 600-;
step 2, stress is eliminated, the preheated gear blank stress eliminating treatment temperature is 630-;
step 3, carburizing, namely, adopting a stepped heating-up and heat-preservation heating mode in a protective atmosphere environment, carrying out temperature equalization at 720 +/-5 ℃ for 25 +/-1 min, and controlling the carbon potential to be 0.50 +/-0.025%; the temperature is kept at 800 plus or minus 5 ℃ for 25 plus or minus 1min, and the carbon potential is controlled at 0.65 plus or minus 0.025%; performing strong infiltration at 950 +/-5 ℃ for 220 +/-1 min, and controlling the carbon potential to be 1.0 +/-0.025%; diffusing at 900 + -5 deg.C for 70 + -1 min, and controlling carbon potential at 0.90 + -0.025%; quenching at 850 + -5 deg.C for 25 + -1 min, and controlling carbon potential at 0.65 + -0.025%;
step 4, tempering treatment, namely firstly tempering and heating at the high temperature of 650 plus 680 ℃, preserving heat for a period of time, and then cooling in air; then quenching and heating at the temperature of 810-; the low-temperature tempering heating temperature is 150-.
In a preferred embodiment of the present invention, in step 1, the gear blank has a composition and weight percentage of 0.28% to 0.36% of C, 0.23% to 0.33% of Si, 2.80% to 3.40% of Cr, 1.80% to 2.10% of Mn, 0.18% to 0.21% of Mo, 0.18% to 0.21% of V, 0.04% to 0.06% of Y, and the balance of iron and inevitable impurities.
In a preferred embodiment of the invention, after the preheating treatment in the step 1, rough turning is carried out on the gear blank to obtain a rough turned gear product; after the stress is eliminated in the step 2, carrying out semi-finish turning on the gear rough turning product to obtain a gear semi-finish turning product; and 4, carrying out tempering treatment on the gear semi-finish turning in the step 4 to carry out finish turning processing to obtain a gear finished product, and sequentially carrying out inspection, shot blasting and boxing on the gear finished product.
In a preferred embodiment of the invention, the shot blasting adopts a vertical hanging shot blasting machine, the gear finished product is placed on a material rack, and QP-4 steel sand is used for performing strong shot blasting for 2 minutes in the forward direction and 2 minutes in the reverse direction.
In a preferred embodiment of the invention, in the step 4, the high-temperature tempering heat preservation time is 30min per 50 mm; the quenching heat preservation time is 40min per 50 mm; the low-temperature tempering and heat preservation time is 25min per 50 mm.
Due to the adoption of the technical scheme, the invention has the beneficial effects that:
1. the gear is processed by a pre-heat treatment process of normalizing, quenching and tempering, and process parameters in the carburizing and quenching process are optimized, so that the distortion of the gear can be greatly reduced, and the distortion of the gear can be reduced by about 30%.
2. The components of the gear are optimized by adding Mn, Cr, Mo, V and rare earth elements, so that the stability of the gear is obviously improved, the hardenability and hardenability of a gear shaft are improved, and the wear resistance and fatigue resistance of the product are improved.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below.
A gear heat treatment process comprises the following steps:
step 1, preheating treatment, namely forging a gear blank firstly, and then normalizing, quenching and tempering, wherein the gear blank comprises 0.28-0.36 wt% of C, 0.23-0.33 wt% of Si, 2.80-3.40 wt% of Cr, 1.80-2.10 wt% of Mn, 0.18-0.21 wt% of Mo, 0.18-0.21 wt% of V, 0.04-0.06 wt% of Y and the balance of iron and inevitable impurities. Normalizing at 900-940 deg.C, charging at a furnace temperature of less than or equal to 500 deg.C, initially heating at 500 deg.C, heating at a rate of less than or equal to 90 deg.C/hr, maintaining at 680 deg.C for 40min per 50mm, and air cooling; the quenching temperature is 860-880 ℃, the furnace temperature is less than or equal to 500 ℃, the furnace is charged, the temperature is raised initially at 500 ℃, the temperature is raised at the speed of less than or equal to 90 ℃/h, the temperature is kept at 680 ℃, the temperature is kept for 40min per 50mm, and then the oil cooling is carried out; the tempering temperature is 600-;
step 2, stress is eliminated, the preheated gear blank stress eliminating treatment temperature is 630-;
step 3, carburizing, namely, adopting a stepped heating-up and heat-preservation heating mode in a protective atmosphere environment, carrying out temperature equalization at 720 +/-5 ℃ for 25 +/-1 min, and controlling the carbon potential to be 0.50 +/-0.025%; the temperature is kept at 800 plus or minus 5 ℃ for 25 plus or minus 1min, and the carbon potential is controlled at 0.65 plus or minus 0.025%; performing strong infiltration at 950 +/-5 ℃ for 220 +/-1 min, and controlling the carbon potential to be 1.0 +/-0.025%; diffusing at 900 + -5 deg.C for 70 + -1 min, and controlling carbon potential at 0.90 + -0.025%; quenching at 850 + -5 deg.C for 25 + -1 min, and controlling carbon potential at 0.65 + -0.025%;
step 4, tempering treatment, namely firstly tempering at high temperature of 650 plus 680 ℃, keeping the temperature for 30min per 50mm, and cooling in air; then quenching and heating at the temperature of 810-; the low-temperature tempering heating temperature is 150-.
Wherein, after the preheating treatment in the step 1, the gear blank is roughly lathed to obtain a roughly lathed gear product; after the stress is eliminated in the step 2, carrying out semi-finish turning on the gear rough turning product to obtain a gear semi-finish turning product; and 4, carrying out tempering treatment on the gear semi-finish turning in the step 4 to carry out finish turning processing to obtain a gear finished product, and sequentially carrying out inspection, shot blasting and boxing on the gear finished product.
The shot blasting adopts a vertical hanging shot blasting machine, the gear finished product is placed on a material rack, and the QP-4 steel grit is used for performing strong shot blasting for 2 minutes in the forward direction and 2 minutes in the reverse direction.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. 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 (5)
1. A gear heat treatment process is characterized by comprising the following steps:
step 1, preheating treatment, namely forging a gear blank, normalizing, quenching and tempering, wherein the normalizing temperature is 900-940 ℃, the furnace temperature is less than or equal to 500 ℃, charging is carried out, the temperature is initially increased at 500 ℃, the temperature is increased at the speed of less than or equal to 90 ℃/h, the temperature is kept at 680 ℃, the temperature is kept for 40min at the temperature-keeping time of every 50mm, and then air cooling is carried out; the quenching temperature is 860-880 ℃, the furnace temperature is less than or equal to 500 ℃, the furnace is charged, the temperature is raised initially at 500 ℃, the temperature is raised at the speed of less than or equal to 90 ℃/h, the temperature is kept at 680 ℃, the temperature is kept for 40min per 50mm, and then the oil cooling is carried out; the tempering temperature is 600-;
step 2, stress is eliminated, the preheated gear blank is subjected to stress elimination treatment at the temperature of 630-;
step 3, carburizing, namely, adopting a stepped heating-up and heat-preservation heating mode in a protective atmosphere environment, carrying out temperature equalization at 720 +/-5 ℃ for 25 +/-1 min, and controlling the carbon potential to be 0.50 +/-0.025%; the temperature is kept at 800 plus or minus 5 ℃ for 25 plus or minus 1min, and the carbon potential is controlled at 0.65 plus or minus 0.025%; performing strong infiltration at 950 +/-5 ℃ for 220 +/-1 min, and controlling the carbon potential to be 1.0 +/-0.025%; diffusing at 900 + -5 deg.C for 70 + -1 min, and controlling carbon potential at 0.90 + -0.025%; quenching at 850 + -5 deg.C for 25 + -1 min, and controlling carbon potential at 0.65 + -0.025%;
step 4, tempering treatment, namely firstly tempering and heating at the high temperature of 650 plus 680 ℃, preserving heat for a period of time, and then cooling in air; then quenching and heating at the temperature of 810-; the low-temperature tempering heating temperature is 150-.
2. The gear heat treatment process according to claim 1, wherein in step 1, the gear blank comprises, by weight, 0.28% to 0.36% of C, 0.23% to 0.33% of Si, 2.80% to 3.40% of Cr, 1.80% to 2.10% of Mn, 0.18% to 0.21% of Mo, 0.18% to 0.21% of V, 0.04% to 0.06% of Y, and the balance of Fe and unavoidable impurities.
3. The gear heat treatment process according to claim 1, wherein the gear blank is subjected to rough turning after the preheating treatment in the step 1 to obtain a rough turned gear product; after the stress is eliminated in the step 2, carrying out semi-finish turning on the gear rough turning product to obtain a gear semi-finish turning product; and 4, carrying out tempering treatment on the gear semi-finish turning in the step 4 to carry out finish turning processing to obtain a gear finished product, and sequentially carrying out inspection, shot blasting and boxing on the gear finished product.
4. The gear heat treatment process according to claim 3, wherein the shot blasting adopts a vertical hanging shot blasting machine, the gear finished product is placed on a material rack, and QP-4 steel sand is used for performing powerful shot blasting for 2 minutes in the forward direction and 2 minutes in the reverse direction.
5. The gear heat treatment process according to claim 1, wherein in the step 4, the high-temperature tempering and heat preservation time is 30min per 50 mm; the quenching heat preservation time is 40min per 50 mm; the low-temperature tempering and heat preservation time is 25min per 50 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811356286.1A CN111187899A (en) | 2018-11-14 | 2018-11-14 | Gear heat treatment process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811356286.1A CN111187899A (en) | 2018-11-14 | 2018-11-14 | Gear heat treatment process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111187899A true CN111187899A (en) | 2020-05-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811356286.1A Pending CN111187899A (en) | 2018-11-14 | 2018-11-14 | Gear heat treatment process |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111850412A (en) * | 2020-08-03 | 2020-10-30 | 苏州亚太金属有限公司 | Steel material for carburized gear and preparation method thereof |
| CN112210713A (en) * | 2020-08-15 | 2021-01-12 | 山东汽车齿轮总厂锻造二分厂 | Gear steel and heat treatment process thereof |
| CN112264772A (en) * | 2020-09-25 | 2021-01-26 | 重庆市巨力冶金制品有限公司 | Preparation and processing method of oil pump driving gear |
| CN112831723A (en) * | 2020-12-31 | 2021-05-25 | 钢铁研究总院 | High-temperature carburization resistant gear steel with large crystal grains and control method |
| CN113862445A (en) * | 2021-09-02 | 2021-12-31 | 江麓机电集团有限公司 | Hot working method of high-performance small-distortion carburized outer ring |
| CN114836709A (en) * | 2022-05-19 | 2022-08-02 | 洛阳汇工轴承科技有限公司 | Carburizing heat treatment process for bearing part of rolling mill |
-
2018
- 2018-11-14 CN CN201811356286.1A patent/CN111187899A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111850412A (en) * | 2020-08-03 | 2020-10-30 | 苏州亚太金属有限公司 | Steel material for carburized gear and preparation method thereof |
| CN112210713A (en) * | 2020-08-15 | 2021-01-12 | 山东汽车齿轮总厂锻造二分厂 | Gear steel and heat treatment process thereof |
| CN112264772A (en) * | 2020-09-25 | 2021-01-26 | 重庆市巨力冶金制品有限公司 | Preparation and processing method of oil pump driving gear |
| CN112831723A (en) * | 2020-12-31 | 2021-05-25 | 钢铁研究总院 | High-temperature carburization resistant gear steel with large crystal grains and control method |
| CN113862445A (en) * | 2021-09-02 | 2021-12-31 | 江麓机电集团有限公司 | Hot working method of high-performance small-distortion carburized outer ring |
| CN114836709A (en) * | 2022-05-19 | 2022-08-02 | 洛阳汇工轴承科技有限公司 | Carburizing heat treatment process for bearing part of rolling mill |
| CN114836709B (en) * | 2022-05-19 | 2024-01-09 | 洛阳汇工轴承科技有限公司 | Carburizing heat treatment process for rolling mill bearing parts |
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Application publication date: 20200522 |