CN113802085B - Micro-carburizing process for improving mechanical property of 8Cr4Mo4V steel for aeroengine bearing - Google Patents

Micro-carburizing process for improving mechanical property of 8Cr4Mo4V steel for aeroengine bearing Download PDF

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CN113802085B
CN113802085B CN202111089881.5A CN202111089881A CN113802085B CN 113802085 B CN113802085 B CN 113802085B CN 202111089881 A CN202111089881 A CN 202111089881A CN 113802085 B CN113802085 B CN 113802085B
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furnace
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steel
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CN113802085A (en
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于兴福
申向阳
魏英华
郑冬月
安敏
赵文增
吴玉胜
苏勇
闫国斌
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Shenyang University of Technology
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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
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    • 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
    • C21D1/32—Soft annealing, e.g. spheroidising
    • 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
    • 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
    • C21D1/773—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material under reduced pressure or vacuum
    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • 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
    • C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
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    • 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
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    • 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
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Abstract

The invention belongs to the technical field of heat treatment, and relates to a micro carburizing treatment method for 8Cr4Mo4V steel for an aeroengine bearing. A micro carburizing treatment method for 8Cr4Mo4V steel for an aeroengine bearing comprises the following steps of 1, carrying out spheroidizing annealing treatment on the 8Cr4Mo4V steel, and carrying out micro carburizing treatment on the steel. 2. And performing micro carburizing and quenching treatment on the 8Cr4Mo4V steel after spheroidizing annealing treatment. And 3, performing high-temperature tempering on the 8Cr4Mo4V steel subjected to the micro carburizing and quenching treatment for three times. The invention aims at the heat treatment of 8Cr4Mo4V steel bearing parts, adopts an atmosphere control furnace for heating and solution treatment, increases the carbon content of the surface layer by adjusting the carbon potential to achieve the effect of increasing the carbon concentration of the surface layer, and simultaneously generates residual compressive stress on the surface after tempering, thereby obviously improving the surface layer hardness, the wear resistance, the impact toughness and the rotary bending fatigue limit strength of the 8Cr4Mo4V steel. The method has low requirement on equipment, is simple to operate, has low cost and has high practical value.

Description

Micro-carburizing process for improving mechanical property of 8Cr4Mo4V steel for aeroengine bearing
Technical Field
The invention belongs to the technical field of heat treatment processes, and relates to a micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for an aeroengine bearing.
Background
The 8Cr4Mo4V steel is a 2 nd generation molybdenum series high alloy bearing steel with extremely high temperature bearing capacity, and is widely applied to DN value lower than 2.4 multiplied by 10 6 Main shaft bearing of aircraft engine. The existing heat treatment of 8Cr4Mo4V mainly aims at obtaining martensite, and after quenching and tempering treatment, higher hardness can be obtained, but the impact toughness and the wear resistance are lower. Carburizing means a process of infiltrating carbon atoms into a surface layer of steel to make a low-carbon steel workpiece have a surface layer of high-carbon steel, and then quenching and low-temperature tempering are carried out to make the surface layer of the workpiece have high hardness and wear resistance, while the central part of the workpiece still maintains the toughness and plasticity of the low-carbon steel. The carburizing technology is generally suitable for low-carbon steel or low-alloy steel, has good carburizing effect and has the defects of special requirements on equipment and high cost. The 8Cr4Mo4V steel is used as one of high-carbon steel, the carbon content in a matrix of the high-carbon steel is almost saturated, if the 8Cr4Mo4V steel is carburized, the regulation and control of the carbon potential are difficult points, and the poor carburization effect and even the reduction of the mechanical property can be caused by the excessively high or excessively low carbon potential.
The invention is different from the traditional carburization mode, the 8Cr4Mo4V steel is subjected to micro carburization treatment by regulating and controlling the atmosphere protective furnace carbon potential while being subjected to heat treatment, so that the surface can obtain high hardness and surface layer pressure stress, the fatigue property is improved, the core can keep good toughness, and the 8Cr4Mo4V steel can obtain excellent comprehensive mechanical property.
Disclosure of Invention
In view of the problems in the prior art, the invention aims to provide a micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for an aeroengine bearing, wherein the micro-carburizing treatment is realized on the surface layer of the 8Cr4Mo4V steel after heat treatment, so that the comprehensive mechanical property indexes such as the hardness, the impact toughness, the rotating bending fatigue limit strength and the like of the surface layer of the steel are obviously improved.
In order to achieve the purpose, the invention adopts the following technical scheme.
A micro carburization process for improving mechanical properties of 8Cr4Mo4V steel for an aeroengine bearing comprises the following steps:
step 1, carrying out spheroidizing annealing treatment on 8Cr4Mo4V steel.
Step 2, micro carburizing and quenching treatment: and (3) placing the spheroidizing annealed 8Cr4Mo4V steel in an atmosphere protection furnace, carrying out solid solution heating and heat preservation, adjusting the carbon potential of the atmosphere protection furnace by adopting methanol and propane, measuring the carbon potential by adopting an oxygen probe, automatically adjusting, and then cooling the sample.
And 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 8-10 ℃/min, preserving the temperature for 2.5 hours, taking out the sample, air-cooling to the room temperature, and performing high-temperature tempering for three times.
Further, in the step 1, the spheroidizing annealing operation is performed after the ring blank is forged and then is placed into an ash cooling state, and when the ash cooling temperature reaches 400-500 ℃. The time from forging to spheroidizing annealing is required to be 16 hours or less. Before annealing, the forging stock is boxed, the box is placed in an effective temperature zone in an annealing furnace, the preheating temperature is 700-750 ℃, the preheating time is 3 hours, then the box is heated to 830-860 ℃, the heat preservation time is 6-7 hours, then the box is cooled to 720-750 ℃ along with the furnace, the heat preservation time is 11-12 hours, then the box is cooled to 680 ℃ along with the furnace at the speed of 20 ℃/h, and then the box is taken out of the furnace and cooled to 500-550 ℃ along with the furnace.
Further, in the step 2, the temperature of the solid solution heating and heat preservation is raised from below 500 ℃ to 840-860 ℃ at the speed of 8-10 ℃/min, the temperature is preserved for 30-40min at 840-860 ℃, then is raised to 1000-1020 ℃ at the speed of 3~6 ℃/min, the temperature is preserved for 15-30min, then is raised to 1075-1110 ℃ at the speed of 6 ℃/min, and the temperature is preserved for 5-20min.
Further, in the step 2, oil with the temperature of more than 150 ℃ is adopted for cooling, the cooling is carried out in an air cooling mode, the cooling is directly quenched into isothermal salt bath with the temperature of 180-220 ℃, and after the temperature is kept for 2 hours, the sample is cooled to room temperature by air. The temperature is required to be cooled to below 220 ℃ from high temperature, and the time is less than 5min.
Further, the control range of the carbon potential in the step 2 is 0.35% -0.65%.
Further, after the quenching in the step 3 is cooled to room temperature, tempering treatment can be performed, and after the quenching is completed, the time interval for performing the first tempering is within 5 hours. There is no strict time requirement between the second and third tempering treatments and the first tempering treatment.
Compared with the prior art, the invention has the beneficial effects of.
The invention aims at the heat treatment of 8Cr4Mo4V steel bearing parts, adopts an atmosphere control furnace for heating and solution treatment, increases the carbon content of the surface layer by adjusting the carbon potential to achieve the effect of increasing the carbon concentration of the surface layer, and simultaneously generates residual compressive stress on the surface after tempering, thereby obviously improving the surface layer hardness, the wear resistance, the impact toughness and the rotary bending fatigue limit strength of the 8Cr4Mo4V steel. The method has low requirement on equipment, is simple to operate, has low cost and has high practical value.
Drawings
FIG. 1 is a photograph of the structure in a quenched state after the end of step 2 in example 1; FIG. 1 (a) shows a superficial layer structure; FIG. 1 (b) shows the core structure.
FIG. 2 is a photograph of the structure in the tempered state after the end of step 3 in example 1; FIG. 2 (a) shows a superficial layer structure; FIG. 2 (b) shows the core structure.
FIG. 3 is a cross-sectional microhardness distribution at the end of step 3 of example 1.
FIG. 4 is a photograph of the structure in a quenched state after the end of step 2 in example 2; FIG. 4 (a) shows a superficial layer structure; FIG. 4 (b) shows the core structure.
FIG. 5 is a photograph of the structure in the tempered state after the end of step 3 in example 2; FIG. 5 (a) shows a superficial layer structure; FIG. 5 (b) shows the core structure.
FIG. 6 is a cross-sectional microhardness distribution at the end of step 3 of example 2.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
A micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for an aeroengine bearing comprises the following steps:
step 1, carrying out spheroidizing annealing treatment on 8Cr4Mo4V steel.
Step 2, micro carburizing and quenching treatment: and (3) placing the spheroidizing annealed 8Cr4Mo4V steel in an atmosphere protection furnace, carrying out solid solution heating and heat preservation, adjusting the carbon potential of the atmosphere protection furnace by adopting methanol and propane, measuring the carbon potential by adopting an oxygen probe, automatically adjusting, and then cooling the sample.
And 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 8-10 ℃/min, preserving the temperature for 2.5 hours, taking out the sample, air-cooling to the room temperature, and performing high-temperature tempering for three times.
Further, in the step 1, the spheroidizing annealing operation is performed after the ring blank is forged and then is placed into an ash cooling state, and when the ash cooling temperature reaches 400-500 ℃. The time from forging to spheroidizing annealing is required to be 16 hours or less. Before annealing, boxing the forging stock, placing the box in an effective temperature zone in an annealing furnace, preheating at 700-750 ℃ for 3h, heating to 830-860 ℃ for 6-7h, cooling to 720-750 ℃ with the furnace, keeping the temperature for 11-12h, cooling to 680 ℃ with the speed of 20 ℃/h, cooling to 500-550 ℃ with the furnace, and taking out of the furnace for air cooling.
Further, in the step 2, the temperature of the solid solution heating and heat preservation is raised from below 500 ℃ to 840-860 ℃ at the speed of 8-10 ℃/min, the temperature is preserved for 30-40min at 840-860 ℃, then is raised to 1000-1020 ℃ at the speed of 3~6 ℃/min, the temperature is preserved for 15-30min, then is raised to 1075-1110 ℃ at the speed of 6 ℃/min, and the temperature is preserved for 5-20min.
Further, in the step 2, oil with the temperature of more than 150 ℃ is adopted for cooling, the cooling is carried out in an air cooling mode, the cooling is directly quenched into isothermal salt bath with the temperature of 180-220 ℃, and after the temperature is kept for 2 hours, the sample is cooled to room temperature by air. The temperature is required to be cooled to below 220 ℃ from high temperature, and the time is less than 5min.
Further, the control range of the carbon potential in the step 2 is 0.35% -0.65%.
Further, after the quenching in the step 3 is cooled to room temperature, tempering treatment can be performed, and after the quenching is completed, the time interval for performing the first tempering is within 5 hours. There is no strict time requirement between the second and third tempering treatments and the first tempering treatment.
Example 1.
And step 1, spheroidizing annealing operation is to perform spheroidizing annealing operation after the ring blank is placed into an ash cooling device after being forged and when the ash cooling temperature reaches 400 ℃. The time from forging to spheroidizing annealing is required to be 15 hours. Before annealing, boxing the forging stock, placing the box in an effective temperature zone in an annealing furnace, preheating at 700 ℃ for 3h, heating to 830 ℃ for 6h, cooling to 720 ℃ with the furnace, keeping the temperature for 11h, cooling to 680 ℃ with the speed of 20 ℃/h, cooling to 500 ℃ with the furnace, and taking out of the furnace for air cooling.
Step 2, micro carburizing and quenching treatment: placing the 8Cr4Mo4V steel subjected to spheroidizing annealing in an atmosphere protection furnace, wherein the temperature is raised to 840 ℃ from below 500 ℃ at the speed of 8 ℃/min, preserving the temperature for 30min at 840 ℃, then raising to 1000 ℃ at the speed of 3 ℃/min, preserving the temperature for 30min, then raising to 1075 ℃ at the speed of 6 ℃/min, preserving the temperature for 5min, the atmosphere protection furnace adopts methanol and propane to adjust the carbon potential, adopts an oxygen probe to measure the carbon potential and automatically adjust the carbon potential, controls the carbon potential to be 0.5%, then adopts direct quenching in an isothermal salt bath at 200 ℃, and cools a sample to room temperature after preserving the temperature for 2 h. The sample is required to be cooled from high temperature to below 220 ℃ for less than 5min.
And 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 10 ℃/min, preserving the heat for 2.5 hours, taking out the sample, air-cooling the sample to the room temperature, and then tempering the sample, wherein the time interval for tempering for the first time is within 5 hours. There is no strict time requirement between the second and third tempering treatments and the first tempering treatment. Three high temperature tempers are required.
And carrying out surface Rockwell hardness, impact property and rotary bending fatigue property tests on the finally heat-treated 8Cr4Mo4V steel.
Example 2.
Step 1, carrying out spheroidizing annealing treatment on 8Cr4Mo4V steel: and after the ring blank is forged, cooling the ring blank in ash, and performing spheroidizing annealing when the ash cooling temperature reaches 500 ℃. The time from forging to spheroidizing annealing is required to be 10 hours. Before annealing, boxing the forging stock, putting the box into an effective temperature zone in an annealing furnace, preheating at 750 ℃ for 3h, then heating to 860 ℃ and keeping the temperature for 7h, then cooling to 750 ℃ along with the furnace, keeping the temperature for 12h, then cooling to 680 ℃ along with the furnace at the speed of 20 ℃/h, then cooling to 550 ℃ along with the furnace, and taking out of the furnace for air cooling.
Step 2, micro carburizing and quenching treatment: placing the 8Cr4Mo4V steel subjected to spheroidizing annealing in an atmosphere protection furnace, wherein the temperature is raised to 860 ℃ from below 500 ℃ at the speed of 10 ℃/min, preserving heat for 40min at 860 ℃, then raised to 1010 ℃ at the speed of 5 ℃/min, preserving heat for 15min, then raised to 1095 ℃ at the speed of 6 ℃/min, preserving heat for 10min, the atmosphere protection furnace adopts methanol and propane to adjust the carbon potential, an oxygen probe is adopted to measure the carbon potential and automatically adjust the carbon potential, the carbon potential is controlled to be 0.65%, then the furnace is directly quenched in an isothermal salt bath at 200 ℃, and the sample is air-cooled to the room temperature after the temperature is preserved for 2 h. The sample is required to be cooled from high temperature to below 220 ℃ for less than 5min.
And 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 10 ℃/min, preserving the heat for 2.5 hours, taking out the sample, air-cooling the sample to the room temperature, and tempering, wherein the time interval for tempering for the first time is within 5 hours. There is no strict time requirement between the second and third tempering treatments and the first tempering treatment.
And carrying out surface Rockwell hardness, impact property and rotary bending fatigue property tests on the finally heat-treated 8Cr4Mo4V steel.
Comparative example 1.
Step 1, carrying out spheroidizing annealing treatment on 8Cr4Mo4V steel: and after the ring blank is forged, cooling the ring blank in ash, and performing spheroidizing annealing when the ash cooling temperature reaches 450 ℃. The time from forging to spheroidizing annealing is required to be 15 hours. Before annealing, boxing the forging stock, placing the box in an effective temperature zone in an annealing furnace, preheating at 720 ℃ for 3h, heating to 840 ℃ for 6h10min, furnace-cooling to 740 ℃ for 11h20min, furnace-cooling to 680 ℃ at a speed of 20 ℃/h, furnace-cooling to 530 ℃ and discharging for air cooling.
Step 2, micro carburizing and quenching treatment: placing 8Cr4Mo4V steel after spheroidizing annealing in an atmosphere protection furnace, wherein the temperature rise process is to raise the temperature from below 500 ℃ to 850 ℃ at the speed of 10 ℃/min, preserving the temperature for 35min at 850 ℃, then raising the temperature to 1020 ℃ at the speed of 6 ℃/min, preserving the temperature for 30min, then raising the temperature to 1110 ℃ at the speed of 6 ℃/min, preserving the temperature for 20min, adopting methanol and propane to carry out carbon potential adjustment in the atmosphere protection furnace, adopting an oxygen probe to measure the carbon potential and automatically adjusting the carbon potential, controlling the carbon potential to be 0.8%, then directly quenching the steel in an isothermal salt bath at 200 ℃, and carrying out air cooling on a sample to room temperature after preserving the temperature for 2 h. The sample is required to be cooled from high temperature to below 220 ℃ for less than 5min.
And 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 10 ℃/min, preserving the heat for 2.5 hours, taking out the sample, air-cooling the sample to the room temperature, tempering, wherein the time interval for tempering for the first time is within 5 hours, and no strict time requirement exists between the tempering for the second time and the third time and the tempering for the first time.
And carrying out surface Rockwell hardness, impact property and rotary bending fatigue property tests on the finally heat-treated 8Cr4Mo4V steel.
Comparative example 2.
Step 1, carrying out spheroidizing annealing treatment on 8Cr4Mo4V steel: and after the ring blank is forged, cooling the ring blank in ash, and performing spheroidizing annealing operation when the ash cooling temperature reaches 470 ℃. The time from forging to spheroidizing annealing is required to be 15 hours. Before annealing, boxing the forging stock, placing the box in an effective temperature zone in an annealing furnace, preheating at 710 ℃ for 3h, heating to 845 ℃, keeping the temperature for 6h and 30min, cooling to 740 ℃ along with the furnace, keeping the temperature for 11h and 15min, cooling to 680 ℃ along with the furnace at the speed of 20 ℃/h, cooling to 540 ℃ along with the furnace, and taking out of the furnace for air cooling.
And 2, placing the spheroidizing annealed 8Cr4Mo4V steel in an atmosphere protective furnace, wherein the temperature is raised to 840 ℃ from below 500 ℃ at the speed of 10 ℃/min, preserving the heat at 840 ℃ for 40min, then raising to 1010 ℃ at the speed of 6 ℃/min, preserving the heat for 25min, then raising to 1100 ℃ at the speed of 6 ℃/min, preserving the heat for 10min, then directly quenching into an isothermal salt bath at 200 ℃, preserving the heat for 2h, and then cooling the sample to room temperature in air. The sample is required to be cooled from high temperature to below 220 ℃ for less than 5min.
And 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 10 ℃/min, preserving the heat for 2.5 hours, taking out the sample, air-cooling the sample to the room temperature, and tempering, wherein the time interval for tempering for the first time is within 5 hours. There is no strict time requirement between the second and third tempering treatments and the first tempering treatment.
And carrying out surface Rockwell hardness, impact property and rotary bending fatigue property tests on the finally heat-treated 8Cr4Mo4V steel.
The above examples were compared with the 8Cr4Mo4V steel of comparative example, giving the following results.
Table 1 comparative test results of examples and comparative examples.
Figure 784603DEST_PATH_IMAGE001
By comparing the examples and the comparative examples, the invention can obviously improve the hardness, the impact toughness and the rotary bending fatigue limit of the material by comprehensively considering.
It can be seen from FIG. 1 (a) that the surface layer of example 1 has more retained austenite and less bainite and martensite; the core part of FIG. 1 (b) is mainly a martensite + bainite composite structure.
As can be seen from fig. 2 (a), in example 1, fine and uniformly distributed carbides are dispersed and precipitated on the tempered ferrite, and a small amount of martensite structure is contained; FIG. 2 (b) shows the core structure, mainly ferrite and fine and uniformly distributed carbides.
It can be seen from fig. 4 (a) that the surface layer of example 2 has more retained austenite and less bainite and martensite; in FIG. 4 (b), the core is mainly a martensite + bainite composite structure.
As can be seen from fig. 5 (a), in example 2, fine and uniformly distributed carbides are dispersed and precipitated on the tempered ferrite, and a small amount of martensite structure is contained; FIG. 5 (b) shows the core structure, mainly ferrite and fine and uniformly distributed carbides.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims (6)

1. A micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for an aeroengine bearing is characterized by comprising the following steps:
step 1, carrying out spheroidizing annealing treatment on 8Cr4Mo4V steel;
step 2, micro carburizing and quenching treatment: placing the 8Cr4Mo4V steel subjected to spheroidizing annealing in an atmosphere protection furnace, performing solid solution heating and heat preservation, adjusting the carbon potential of the atmosphere protection furnace by adopting methanol and propane, measuring the carbon potential by adopting an oxygen probe, automatically adjusting, and then cooling a sample, wherein the carbon potential control range is between 0.35% and 0.65%;
and 3, placing the quenched 8Cr4Mo4V steel in an atmosphere protection furnace or a vacuum furnace, raising the temperature to 550 ℃ from the room temperature at a speed of 8-10 ℃/min, preserving the temperature for 2.5 hours, taking out the sample, air-cooling to the room temperature, and performing high-temperature tempering for three times.
2. The micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for an aeroengine bearing according to claim 1, wherein in the step 1, the spheroidizing annealing operation is performed after the ring blank is forged and then is placed in an ash cooling state, and when the ash cooling temperature reaches 400-500 ℃; the time from forging to spheroidizing annealing is required to be less than or equal to 16h; before annealing, the forging stock is boxed, the box is placed in an effective temperature zone in an annealing furnace, the preheating temperature is 700-750 ℃, the preheating time is 3 hours, then the box is heated to 830-860 ℃, the heat preservation time is 6-7 hours, then the box is cooled to 720-750 ℃ along with the furnace, the heat preservation time is 11-12 hours, then the box is cooled to 680 ℃ along with the furnace at the speed of 20 ℃/h, and then the box is taken out of the furnace and cooled to 500-550 ℃ along with the furnace.
3. The micro-carburizing process for improving the mechanical property of the 8Cr4Mo4V steel for the bearing of the aircraft engine as claimed in claim 1, wherein in the step 2, the temperature rise in the solution heating and heat preservation process is from 500 ℃ below at a rate of 8-10 ℃/min to 840 ℃ to 860 ℃, the temperature is preserved at 840 ℃ to 860 ℃ for 30-40min, then the temperature is raised at a rate of 3~6 ℃/min to 1000 ℃ to 1020 ℃ for 15-30min, then the temperature is raised at a rate of 6 ℃/min to 1075 ℃ to 1110 ℃, and the temperature is preserved for 5-20min.
4. The micro carburizing process for improving the mechanical property of the 8Cr4Mo4V steel for the aeroengine bearing according to claim 1, wherein in the step 2, the cooling is carried out by adopting oil with the temperature of more than 150 ℃, the cooling is carried out in an air cooling mode, the cooling is directly quenched into isothermal salt bath with the temperature of 180-220 ℃, and after the temperature is kept for 2 hours, the sample is cooled in air to room temperature.
5. The micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for aeroengine bearings according to claim 4, wherein the cooling is required to be below 220 ℃ for less than 5min.
6. The micro-carburizing process for improving the mechanical property of 8Cr4Mo4V steel for an aeroengine bearing according to claim 1, wherein the tempering treatment is performed after the quenching in step 3 is cooled to room temperature, and the time interval for performing the first tempering is within 5h after the quenching is completed; there is no strict time requirement between the second and third tempering treatments and the first tempering treatment.
CN202111089881.5A 2021-09-17 2021-09-17 Micro-carburizing process for improving mechanical property of 8Cr4Mo4V steel for aeroengine bearing Active CN113802085B (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA624487A (en) * 1961-07-25 F. Jatczak Chester Case carburized high temperature bearing members
CN107254566A (en) * 2017-06-29 2017-10-17 中国航发哈尔滨轴承有限公司 A kind of 8Cr4Mo4V bearing parts dimensional stability handling process
CN111411203A (en) * 2020-04-15 2020-07-14 沈阳工业大学 Method for obtaining 8Cr4Mo4V steel and optimizing quenching process

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA624487A (en) * 1961-07-25 F. Jatczak Chester Case carburized high temperature bearing members
CN107254566A (en) * 2017-06-29 2017-10-17 中国航发哈尔滨轴承有限公司 A kind of 8Cr4Mo4V bearing parts dimensional stability handling process
CN111411203A (en) * 2020-04-15 2020-07-14 沈阳工业大学 Method for obtaining 8Cr4Mo4V steel and optimizing quenching process

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
李昭昆等."国内外轴承钢的现状与发展趋势".2016,第28卷(第3期),全文. *
魏英华."8Cr4Mo4V钢热处理组织与尺寸稳定性研究".2021,第2021年卷(第01期),全文. *

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