Short-process oil quenching-oil removal integrated treatment method for powder high-speed steel

Abstract

The invention belongs to the technical field of powder metallurgy, and discloses a short-process powder high-speed steel oil quenching-oil removal integrated treatment method which is characterized in that the surface of high-speed steel is coated with a specific heat preservation and insulation coating, so that the high-speed steel can be subjected to continuous heat preservation, heat insulation, oxidation resistance and decarburization resistance in the heating and transferring process; effective hardening can be achieved in the oil quenching process, and the frame is made of a specific alloy with the surface coated with a heat preservation and insulation coating with a certain thickness, so that the heat radiation superposition heat preservation effect on the high-speed steel is achieved; in addition, martensite step quenching oil is selected, and effective hardening of the whole surface of the high-speed steel is achieved while deformation and cracking of the high-speed steel are prevented by means of the good fluidity of the martensite step quenching oil at the specific temperature. And finally, by limiting the oil quenching transfer time, matching with a transfer mode of forklift consignment and combining with a coating layer which is coated on the surface of the high-speed steel and can be quickly separated after being immersed in oil, the production time is effectively shortened, the production cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology and relates to a short-process integrated oil quenching and degreasing treatment method for high-speed powder steel. Background Technology

[0002] After high-speed steel is formed at high temperature, it needs to undergo heat treatment to meet the requirements of later use. This heat treatment process includes one oil quenching and multiple tempering processes. In the first oil quenching heat treatment, after the high-speed steel is heated, it needs to be immediately immersed in oil for quenching to obtain high hardness. However, in actual production, due to space limitations, high-speed steel cannot be immediately immersed in oil after being taken out of the heating furnace. A slightly longer transfer time leads to heat loss, thus failing to achieve the desired high-temperature hardening effect and resulting in a decrease in hardness.

[0003] To achieve high hardness, high-speed steel often needs to be heated to above 1160℃, or even above 1200℃. If the high-speed steel is transferred to oil after heating, and the transfer time in air exceeds 10 seconds or even 30 seconds, the surface temperature of the high-speed steel will drop by hundreds of degrees Celsius, rendering the hardening process ineffective. Currently, there are no publicly reported technologies for maintaining hardness through oil quenching under these conditions. Furthermore, oil residue remains on the surface of the high-speed steel after oil quenching. If not thoroughly removed, this can easily lead to high-temperature ignition and damage to equipment. Although separate oil draining and drying methods are used in industry, this prolongs the production process.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a short-process integrated oil quenching and degreasing method for powder high-speed steel, so as to solve the problems that the long transfer time of the oil quenching process of existing high-speed steel easily leads to a decrease in hardness and the extended production time caused by degreasing of the surface of high-speed steel after oil quenching.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a short-process integrated oil quenching and degreasing treatment method for powder high-speed steel. First, a first thermal insulation coating is applied to the surface of the high-speed steel to be heat-treated. Then, a rack coated with a second thermal insulation coating is used to perform radiative superposition insulation on the high-speed steel. The time, oil temperature, and immersion time of the high-speed steel during transfer from the furnace to the martensitic isothermal quenching oil are controlled. Finally, combined with a tempering process, a short-process oil quenching and degreasing treatment for high-speed steel is achieved. See also... Figure 1 The processing method specifically includes the following steps: Step 1: Apply the first heat insulation coating to the surface of the high-speed steel to be heat treated, and place the coated high-speed steel on the rack coated with the second heat insulation coating. Step 2: First, place the material rack and the coated high-speed steel into the heating furnace for heating. Then, transfer the heated high-speed steel to the martensitic isothermal graded quenching oil. Control the time for the high-speed steel to be transferred from the furnace to the martensitic isothermal graded quenching oil to be 5s~40s, the oil temperature to be 105℃~130℃, and the immersion time to be 60min~180min. Step 3: After removing the high-speed steel from the martensitic isothermal quenching oil and draining the oil, put it back into the heating furnace and heat it to 250℃~350℃ at a heating rate of 2℃ / min~10℃ / min. Hold it at this temperature for 30min~90min to remove the oil stains. Then heat it to the target temperature at a heating rate of 3℃ / min~31℃ / min.

[0007] Specifically, in step 1, the coating of the first thermal insulation coating on the surface of the high-speed steel is a multi-element ceramic nano aerogel, Al2O3 nano porous fiber coating or nano resin, and the material rack is a 316L stainless steel material rack, GH2848, GH4099 or GH5188 high temperature alloy material rack. The coating of the second thermal insulation coating on the surface of the material rack is a ZS-1 thermal insulation coating, mullite porous ceramic or calcium feldspar porous ceramic.

[0008] Furthermore, the first thermal insulation coating on the surface of the high-speed steel in step 1 is applied 2 to 4 times, and each coating needs to be dried at room temperature for 4 to 48 hours. There are no restrictions on the number of times, the method of application, and the drying time of the second thermal insulation coating on the surface of the material rack. In principle, as long as the second thermal insulation coating can reach a specific thickness and be applied evenly, it is acceptable. The specific application can be adjusted according to the temperature and humidity of the environment during operation.

[0009] Furthermore, in step 2, during the process of transferring the material rack and high-speed steel to the martensitic isothermal quenching oil, the high-speed steel is covered with asbestos or a glass cover for insulation.

[0010] Furthermore, the thickness of the first thermal insulation coating on the surface of the high-speed steel is 0.2mm~0.8mm, and the thickness of the second thermal insulation coating on the surface of the material rack is 0.1mm~0.5mm. The thermal conductivity of both the first and second thermal insulation coatings is 0.005W / (m·K)~0.05W / (m·K).

[0011] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1) By coating the surface of high-speed steel with a certain thickness of heat-insulating coating that can be automatically removed during the oil quenching process, the high-speed steel can not only be continuously kept warm, heat-insulated, anti-oxidized, and prevent decarburization during heating and transfer, but also be effectively hardened during the oil quenching process. 2) By using a specific alloy frame with a certain thickness of heat-insulating coating on the surface, the high-speed steel achieves a superimposed heat radiation insulation effect. 3) The good fluidity of martensitic graded quenching oil at a specific temperature can effectively promote the martensitic transformation of high-speed steel, prevent deformation and cracking of high-speed steel, and achieve effective hardening of the entire surface of high-speed steel. 4) By limiting the oil quenching transfer time, using forklift transportation, and combining the high-speed steel surface coating with a coating layer that can be quickly removed after oil immersion, production time is effectively shortened, production costs are reduced, and production efficiency is improved. Attached Figure Description

[0012] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A flowchart of a short-process integrated oil quenching and degreasing treatment method for high-speed powder steel provided by the present invention; Figure 2 This is a graph showing the hardness values ​​of the high-speed steel obtained in Example 1 of the present invention. Figure 3 The image shows the hardness values ​​of the high-speed steel obtained in Comparative Example 1. Figure 4 This is an electron microscope image of the high-speed steel obtained in Example 2 of the present invention; Figure 5 Optical images of the high-speed steel prepared in Comparative Example 2; Figure 6 This is a graph showing the hardness values ​​of the high-speed steel obtained in Example 3 of the present invention. Figure 7 The graph shows the hardness values ​​of the high-speed steel obtained in Comparative Example 3. Figure 8 This is a graph showing the hardness values ​​of the high-speed steel obtained in Example 4 of the present invention. Figure 9 The image shows the hardness values ​​of the high-speed steel prepared in Comparative Example 4. Detailed Implementation

[0015] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0016] This invention provides a short-process integrated oil quenching and degreasing treatment method for powder high-speed steel. First, a first heat-insulating coating is applied to the surface of the high-speed steel to be heat-treated. Then, a rack coated with a second heat-insulating coating is used to perform heat radiation-type superimposed heat insulation on the high-speed steel. The time, oil temperature, and immersion time of the high-speed steel from the furnace to the martensitic isothermal quenching oil are controlled. Finally, combined with the tempering process, a short-process oil quenching and degreasing treatment of high-speed steel is achieved.

[0017] It should be noted that the present invention does not limit the coating method and number of coatings for ZS-1 thermal insulation coating, mullite porous ceramic or anorthite porous ceramic. In principle, as long as a second thermal insulation coating of a specific thickness (0.1mm~0.5mm) and uniformity can be achieved, it is acceptable. In actual operation, it can be adapted to the temperature and humidity of the coating environment.

[0018] Specifically, the first thermal insulation coating formed by the multi-element ceramic nano-aerogel, Al2O3 nanoporous fiber coating, or nano-resin in this invention can automatically detach during oil quenching. It can provide thermal insulation, heat insulation, anti-oxidation, and anti-decarburization functions during heating and transfer, and can also effectively harden the surface of high-speed steel. The martensitic isothermal graded quenching oil used in the oil quenching process, due to its high temperature, can quickly remove the heat from the surface of high-speed steel, allowing a large number of phases with different coefficients of thermal expansion on the surface to achieve the effect of martensitic phase transformation. Moreover, the temperature difference between the oil temperature and the surface temperature of the heated high-speed steel is small, which can effectively avoid thermal stress deformation and cracking caused by phase transformation. The martensitic isothermal graded quenching oil has good fluidity at high temperature, which can quickly remove the thermal insulation coating from the surface of the oil-immersed high-speed steel, and effectively harden the entire surface of the high-speed steel.

[0019] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] Example 1

[0021] This embodiment provides a short-process integrated oil quenching and degreasing treatment method for high-speed powder steel, including the following steps: Step 1: Coat the surface of the high-speed steel to be heat-treated with a multi-element ceramic nano-aerogel, such as Al2O3-SiO2, with a thickness of 0.2 mm. Then place it on a 316L stainless steel rack. The surface of the 316L stainless steel rack is coated with ZS-1 thermal insulation coating with a thickness of 0.1 mm. The thermal conductivity of both the multi-element ceramic nano-aerogel and the ZS-1 thermal insulation coating is 0.005 W / (m·K). The multi-element ceramic nano-aerogel is coated twice. After the first coating, it needs to be dried at room temperature for 4 hours before the second coating is applied and dried at room temperature for 48 hours. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is completed, use a forklift to transport the rack to the quenching oil. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 20 seconds, the oil temperature is 105℃, and the immersion time is 60 minutes. Step 3: Remove the material rack holding the high-speed steel from the oil and place it on the oil drain rack for 30 minutes; then put it into the heating furnace and heat it to 250°C at a heating rate of 2°C / min, hold it at that temperature for 30 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 3°C / min.

[0022] Comparative Example 1

[0023] This comparative example provides a method for oil quenching and degreasing high-speed steel, including the following steps: Step 1: Place the high-speed steel to be heat-treated on a 316L stainless steel rack. The surface of the 316L stainless steel rack is not treated. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is completed, use a forklift to transport the rack to the quenching oil. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 20 seconds. The oil temperature is room temperature, and the immersion time is 60 minutes. Step 3: Remove the rack holding the high-speed steel from the oil and place it on the oil drain rack for 30 minutes; then put it into the heating furnace and heat it to 250°C at a heating rate of 2°C / min. Hold it at this temperature for 30 minutes, then remove it to safely remove the oil stains. Let it air cool to room temperature, then put it back into the heating furnace and heat it to the target temperature at a heating rate of 3°C / min.

[0024] It should be noted that, Figure 2 The hardness values ​​of the high-speed steel prepared in Example 1 of this invention are HRC hardness values ​​of 66.4, 67.1, and 67.1, respectively. Figure 3 The values ​​are the hardness values ​​of the high-speed steel prepared in Comparative Example 1. The high-speed steel in Comparative Example 1 has a lower hardness, with HRC hardness values ​​of 59.9, 60.4, and 61.2, respectively. Obviously, the hardness of the high-speed steel in Example 1 of the present invention is higher than that in Comparative Example 1. However, Comparative Example 1 has a poor hardening effect because it was not coated with a heat insulation coating.

[0025] Example 2

[0026] This embodiment provides a short-process integrated oil quenching and degreasing treatment method for high-speed powder steel, including the following steps: Step 1: Coat the surface of the high-speed steel to be heat-treated with nano-resin to a thickness of 0.8 mm, and then place it on a GH2848 high-temperature alloy rack. The surface of the GH2848 high-temperature alloy rack is coated with ZS-1 thermal insulation coating to a thickness of 0.5 mm. The thermal conductivity of both the nano-resin and the ZS-1 thermal insulation coating is 0.05 W / (m·K). The nano-resin is coated 4 times. After the first coating, it needs to be dried at room temperature for 48 hours, then the second coating is applied and dried at room temperature for 4 hours, then the third coating is applied and dried at room temperature for 6 hours, and then the fourth coating is applied and dried at room temperature for 8 hours. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is completed, use a forklift to transport the rack to the quenching oil. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 5 seconds, the oil temperature is 130℃, and the immersion time is 180 minutes. Step 3: Remove the rack holding the high-speed steel from the oil and place it on the oil drain rack for 150 minutes; then put it into the heating furnace and heat it to 350°C at a heating rate of 10°C / min, hold it at that temperature for 90 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 31°C / min.

[0027] Comparative Example 2

[0028] This comparative example provides a method for oil quenching and degreasing high-speed steel, including the following steps: Step 1: Coat the surface of the high-speed steel to be heat-treated with a multi-element ceramic nano-aerogel, such as Al2O3-SiO2, with a thickness of 0.8 mm. Then place it on a GH2848 high-temperature alloy rack. The surface of the GH2848 high-temperature alloy rack is coated with ZS-1 thermal insulation coating with a thickness of 0.5 mm. The thermal conductivity of both the multi-element ceramic nano-aerogel and the ZS-1 thermal insulation coating is 0.05 W / (m·K). The multi-element ceramic nano-aerogel is coated twice. After the first coating, it needs to be dried at room temperature for 48 hours before the second coating is applied and dried at room temperature for 4 hours. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is complete, use a forklift to transport the rack to the quenching oil. The time from when the high-speed steel comes out of the furnace to when it is immersed in No. 20 machine oil is 3 seconds. The oil temperature is 180 minutes. Step 3: Remove the rack holding the high-speed steel from the oil and place it on the oil drain rack for 150 minutes; then put it into the heating furnace and heat it to 350°C at a heating rate of 10°C / min, hold it at that temperature for 90 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 31°C / min.

[0029] It should be noted that, Figure 4 The image shown is an electron microscope image of the high-speed steel prepared in Example 2 of this invention. Figure 5 The image shows an optical image of the high-speed steel prepared in Comparative Example 2. It is clear that the high-speed steel prepared in Comparative Example 2 cracked due to differences in the oil used for oil quenching, the corresponding time, the oil temperature, and the immersion time.

[0030] Example 3

[0031] This embodiment provides a short-process integrated oil quenching and degreasing treatment method for high-speed powder steel, including the following steps: Step 1: Coat the surface of the high-speed steel to be heat-treated with a multi-element ceramic nano-aerogel, such as Al2O3-SiO2, with a thickness of 0.5mm. Then place it on a GH4099 high-temperature alloy rack. The surface of the GH4099 high-temperature alloy rack is coated with ZS-1 thermal insulation coating with a thickness of 0.3mm. The thermal conductivity of both the multi-element ceramic nano-aerogel and the ZS-1 thermal insulation coating is 0.0275W / (m·K). The multi-element ceramic nano-aerogel is coated three times. After the first coating, it needs to be dried at room temperature for 26 hours. Then, the second coating is applied and dried at room temperature for 26 hours. Finally, the third coating is applied and dried at room temperature for 12 hours. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is completed, use a forklift to transport the rack to the quenching oil. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 40 seconds, the oil temperature is 117.5℃, and the immersion time is 120 minutes. Step 3: Remove the material rack holding the high-speed steel from the oil and place it on the oil drain rack for 90 minutes; then put it into the heating furnace and heat it to 300°C at a heating rate of 6°C / min, hold it at that temperature for 60 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 17°C / min.

[0032] Comparative Example 3

[0033] This comparative example provides a method for oil quenching and degreasing high-speed steel, including the following steps: Step 1: Coat the surface of the high-speed steel to be heat-treated with a multi-element ceramic nano-aerogel, such as Al2O3-SiO2, with a thickness of 0.5mm. Then place it on a GH4099 high-temperature alloy rack. The surface of the GH4099 high-temperature alloy rack is coated with ZS-1 thermal insulation coating with a thickness of 0.3mm. The thermal conductivity of both the multi-element ceramic nano-aerogel and the ZS-1 thermal insulation coating is 0.0275W / (m·K). The multi-element ceramic nano-aerogel is coated three times. After the first coating, it needs to be dried at room temperature for 26 hours. Then, the second coating is applied and dried at room temperature for 26 hours. Finally, the third coating is applied and dried at room temperature for 12 hours. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is completed, use a forklift to transport the rack to the quenching oil. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 60 seconds, the oil temperature is 117.5℃, and the immersion time is 120 minutes. Step 3: Remove the rack holding the high-speed steel from the oil and place it on the oil drain rack for 480 minutes; then put it into the heating furnace and heat it to 300°C at a heating rate of 6°C / min, hold it at that temperature for 60 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 17°C / min.

[0034] It should be noted that, Figure 6 The hardness values ​​of the high-speed steel prepared in Example 3 of this invention are HRC hardness values ​​of 66.9, 66.5, and 66.8, respectively. Figure 7 The hardness values ​​of the high-speed steel prepared in Comparative Example 3 are shown. Obviously, compared with the conventional process, the production time of Example 3 of the present invention is shortened by about 6.5 hours, which reduces the cost. The high-speed steel in Comparative Example 3 has low hardness, with HRC hardness values ​​of 55.8, 59.2 and 59.9, respectively. Due to the long oil quenching transfer time, the hardening effect is poor.

[0035] Example 4

[0036] This embodiment provides a short-process integrated oil quenching and degreasing treatment method for high-speed powder steel, including the following steps: Step 1: Apply an Al2O3 nanoporous fiber coating with a thickness of 0.4 mm to the surface of the high-speed steel to be heat-treated, and then place it on a GH5188 high-temperature alloy rack. The surface of the GH5188 high-temperature alloy rack is coated with a mullite porous ceramic coating with a thickness of 0.2 mm. The thermal conductivity of both the Al2O3 nanoporous fiber coating and the mullite porous ceramic coating is 0.015 W / (m·K). The Al2O3 nanoporous fiber coating is applied twice, and after the first coating, it needs to be dried at room temperature for 8 hours before the second coating is applied and dried at room temperature for 12 hours. It should be noted that in this step, the mullite porous ceramic coating can be replaced with anorthite porous ceramic coating. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is complete, use a forklift to transport the rack to the quenching oil. During the transport, cover the high-speed steel with asbestos (or a glass cover) to keep it warm. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 30 seconds, the oil temperature is 110℃, and the immersion time is 100 minutes. Step 3: Remove the material rack holding the high-speed steel from the oil and place it on the oil drain rack for 100 minutes; then put it into the heating furnace and heat it to 280°C at a heating rate of 3°C / min, hold it at that temperature for 50 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 10°C / min.

[0037] Comparative Example 4

[0038] This comparative example provides a method for oil quenching and degreasing high-speed steel, including the following steps: Step 1: Coat the surface of the high-speed steel to be heat-treated with Al2O3 nanoporous fiber coating with a thickness of 0.4 mm, and then place it on a GH5188 high-temperature alloy rack. The surface of the GH5188 high-temperature alloy rack is coated with mullite porous ceramic coating with a thickness of 0.2 mm. The thermal conductivity of both the Al2O3 nanoporous fiber coating and the mullite porous ceramic coating is 0.015 W / (m·K). The Al2O3 nanoporous fiber coating is applied twice, and after the first coating, it needs to be dried at room temperature for 8 hours before the second coating is applied and dried at room temperature for 12 hours. Step 2: Place the rack and high-speed steel into the heating furnace. After heating is complete, use a forklift to transport the rack to the quenching oil. During the transport, cover the high-speed steel with asbestos (or a glass cover) to keep it warm. The time from when the high-speed steel comes out of the furnace to when it is immersed in the martensitic isothermal quenching oil is 30 seconds, the oil temperature is 110℃, and the immersion time is 100 minutes. Step 3: Remove the rack holding the high-speed steel from the oil and place it on the oil drain rack for 100 minutes; then put it into the heating furnace and heat it to 400°C at a heating rate of 20°C / min, hold it for 120 minutes to safely remove the oil stains, and then heat it to the target temperature at a heating rate of 2°C / min.

[0039] It should be noted that, Figure 8 The hardness values ​​of the high-speed steel prepared in Example 4 of this invention are HRC hardness values ​​of 66.2, 66.4, and 65.8, respectively. Figure 9To compare the hardness values ​​of the high-speed steel prepared in Comparative Example 4, it is clear that compared with the conventional process, the production time of Example 4 of this invention is shortened by about 0.75 hours, reducing costs. Assuming the room temperature is 20°C and the target temperature is 540°C, the time used in step 3 of Example 4 is: (280-20) / 3+50+(540-280) / 10≈163 min; while the time used in step 3 of Comparative Example 4 is: (400-30) / 20+120+(540-400) / 2≈209 min, so the difference is close to 45 min, i.e. 0.75 hours. The high-speed steel in Comparative Example 4 has lower hardness, with HRC hardness values ​​of 58.9, 57.9, and 59.3, respectively. This is because the tempering process parameters exceed the required range, resulting in poor hardening effect.

[0040] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0041] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A short-process integrated oil quenching and degreasing treatment method for high-speed powder steel, characterized in that, First, a first heat-insulating coating is applied to the surface of the high-speed steel to be heat-treated. Then, a rack coated with a second heat-insulating coating is used to perform heat radiation-type superimposed heat insulation on the high-speed steel. The time, oil temperature, and immersion time of the high-speed steel from the furnace to the martensitic isothermal graded quenching oil are controlled. Finally, combined with the tempering process, a short-process high-speed steel oil quenching-degreasing treatment is achieved.

2. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 1, characterized in that, Specifically, the steps include the following: Step 1: Apply the first heat insulation coating to the surface of the high-speed steel to be heat treated, and place the coated high-speed steel on the rack coated with the second heat insulation coating. Step 2: First, place the material rack and the coated high-speed steel into the heating furnace for heating. Then, transfer the heated high-speed steel to the martensitic isothermal graded quenching oil. Control the time for the high-speed steel to be transferred from the furnace to the martensitic isothermal graded quenching oil to be 5s~40s, the oil temperature to be 105℃~130℃, and the immersion time to be 60min~180min. Step 3: After removing the high-speed steel from the martensitic isothermal quenching oil and draining the oil, put it back into the heating furnace and heat it to 250℃~350℃ at a heating rate of 2℃ / min~10℃ / min. Hold it at this temperature for 30min~90min to remove the oil stains. Then heat it to the target temperature at a heating rate of 3℃ / min~31℃ / min.

3. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 2, characterized in that, In step 1, the material rack is a 316L stainless steel material rack or a GH2848, GH4099, or GH5188 high-temperature alloy material rack.

4. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 2, characterized in that, In step 1, the first thermal insulation coating is applied 2 to 4 times, and each coating needs to be dried at room temperature for 4 to 48 hours.

5. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 2, characterized in that, In step 2, during the process of transferring the material rack and high-speed steel to the martensitic isothermal quenching oil, the high-speed steel is covered with asbestos or a glass cover for insulation.

6. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 1, characterized in that, The coating of the first thermal insulation coating is a multi-element ceramic nano-aerogel, Al2O3 nanoporous fiber coating or nano-resin.

7. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 6, characterized in that, The thickness of the first thermal insulation coating is 0.2mm to 0.8mm.

8. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 1, characterized in that, The coating material for the second thermal insulation coating is ZS-1 thermal insulation coating, mullite porous ceramic or calcium feldspar porous ceramic.

9. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 8, characterized in that, The thickness of the second thermal insulation coating is 0.1mm to 0.5mm.

10. The short-process powder high-speed steel oil quenching-degreasing integrated treatment method according to claim 1, characterized in that, The thermal conductivity of both the first and second thermal insulation coatings is 0.005 W / (m·K) to 0.05 W / (m·K).

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