A dense thin layer vanadiumizing agent for tap surface and a method and device for preparing a dense thin vanadiumizing layer on the tap surface

Abstract

The invention belongs to the wear-resistant strengthening technology of metal surface, and discloses a dense thin layer vanadiumizing agent for the surface of a tap, including sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, boron carbide B4C, a carburizer, sodium fluoride NaF and a catalytic agent. The invention also discloses a method and a device for preparing a dense thin vanadiumizing layer on the surface of a tap by using the above-mentioned vanadiumizing agent. The vanadiumizing agent of the invention contains a carburizer and a catalytic agent, and eliminates the problems of discontinuity of the vanadiumizing layer at 880-950°C, V2C phase in the surface layer and loose holes in the traditional TD method. By vanadizing a micro-tap made of HSS steel with the invention, a dense VC layer of 1-4 μm can be obtained, and the surface hardness is the highest, reaching Hv3000 or more. The vanadiumizing process of the invention makes the tapping of the tap smooth, and the service life is increased by about 2 times. The advantages include short vanadiumizing time, high productivity, low vanadiumizing temperature, long service life of the vanadiumizing crucible, etc. In addition, using HSS steel to replace HSSE as a tap also significantly reduces the material cost.

Description

Technical Field

[0001] The invention belongs to the technical field of metal wear-resistant strengthening, and in particular relates to a dense thin layer vanadiumizing agent on the surface of a tap and a method and a device for preparing the dense thin vanadiumizing layer on the surface of the tap. Background Art

[0002] Modern metal product processing is developing rapidly towards miniaturization, micro-miniaturization and precision. Many high-hardness metal products require micro-hole tapping. Tapping on high-hardness materials is the most difficult of all machining processes. The threads formed after tapping must not only meet the standard requirements, but also be tightly screwed with the matching bolts.

[0003] When tapping, micro taps not only have to remove the base metal and lead it out along the chip groove in a narrow space, but are also held tightly by the rebound force of the base, causing severe wear on the front and rear cutting edges and generating heat, which can cause a series of problems such as the tap being stuck, sticking, and vibrating.

[0004] The smaller the tap, the higher the base hardness, and the more serious these problems are. This places higher performance requirements on the cutting edge hardness of micro taps and the friction coefficient with the processed material.

[0005] In order to improve the performance of micro taps, expensive Co-containing (5.0~12wt%) high-speed steel HSSE is used instead of ordinary HSS high-speed steel to make micro taps. To a certain extent, the high-temperature hardness and toughness of the tap edge are improved, and the service life is improved, but the improvement is limited, and the cost investment is far higher than the benefits of performance improvement. TiN, TiCN, TiCrAlN and other high-hardness films are deposited on the surface of the tap. Due to the weak film / substrate bonding, tapping often causes problems such as film shedding, which cannot be widely used. Vanadiumizing the surface of the tap to form a high-hardness VC layer, and the friction coefficient with most steel is small, which is an effective method to strengthen micro taps. However, the traditional TD (Thermal Diffusion) method of vanadiumizing takes a long time, has a high temperature, and a large thickness. The thick VC layer formed on the surface of the tap is easy to break under the action of the torsional force of tapping. However, reducing the vanadiumizing time and lowering the temperature can only produce a discontinuous vanadiumizing layer, which has no practical value. In addition, the TD method is easy to form a V2C layer on the surface of HSS by vanadiumizing at low temperature for a short time, which significantly reduces the hardness and increases the friction coefficient with the processed metal, which also significantly affects the performance of the vanadiumizing layer. How to obtain a thinner and denser VC layer on the surface of micro taps is the key to improving the tapping life of micro taps. Summary of the invention

[0006] In order to solve the above-mentioned shortcomings, the present invention provides a dense thin layer vanadiumizing agent on the surface of a tap, a method and a device for preparing a dense thin vanadiumizing layer on the surface of a tap, so as to use the above-mentioned vanadiumizing agent to make HSS steel and improve the tapping life of micro taps.

[0007] The invention discloses a dense thin layer vanadium infiltration agent suitable for the surface of a tap, which comprises sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, boron carbide B4C, a carburizer, sodium fluoride NaF and a catalyzer.

[0008] Specifically, the content of sodium tetraborate Na2B4O7 is 63.0~75.0wt%, the content of vanadium pentoxide V2O5 is 11~15wt%, the content of boron carbide powder B4C is 3.0~5.0wt%, the content of sodium fluoride NaF is 9~12wt%, the content of recarburizer is 2~4wt% and the content of catalyst is 0.6~1 wt%.

[0009] Specifically, the sodium tetraborate Na2B4O7 is 99wt% borax and is calcined at 500°C for 20 minutes;

[0010] The catalyst is 99wt% nano powder; the recarburizer is 99% submicron powder; and the boron carbide B4C is 99% 100-150 mesh powder.

[0011] The present invention also provides a method for preparing a dense thin vanadium-infiltrated layer on the surface of a tap by using the dense thin layer vanadium-infiltrated agent on the surface of a tap described in any of the above schemes, comprising the following steps.

[0012] Step 1: Weigh the recarburizer and catalyst powders according to the required ratio into a mechanical mixer, mix mechanically for 10 minutes, and then pour into the bottom of the vanadium-infiltrated crucible.

[0013] Step 2: Weigh sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, sodium fluoride NaF and boron carbide powder B4C according to the ratio and put them into a mechanical mixer. After stirring for 20 minutes, pour one-third of the mixed powder into the vanadiumizing crucible to cover the carburizer and catalyst powder at the bottom, then place the tap on the mixed powder, and finally pour the remaining mixed powder into the vanadiumizing crucible to cover the miniature tap.

[0014] Step 3: Place the vanadizing crucible in a furnace body with a vibration table. The vibration of the vibration table is transmitted to the vanadizing crucible through the refractory bricks. After covering the furnace top cover, heat it to 880~950℃ vanadizing temperature at a heating rate of 5~7℃ / min, turn on mechanical vibration, and vanadize for 120~240min.

[0015] Step 4: After the vanadiumizing is completed, turn off the heating power of the furnace body and stop the vibration of the vibration table. When the temperature of the vanadiumizing crucible drops to 800℃, take out the tap and put it into 10% sodium hydroxide NaOH solution and boil it for 15 minutes to remove the salt on the surface of the tap.

[0016] Specifically, in step 1, the vanadiumizing crucible is capable of withstanding temperatures above 1000°C. The vanadiumizing crucible is made of a Fe55Ni30Cr15 high temperature alloy capable of withstanding vibration and impact, and can withstand a vanadiumizing life of more than 10 times at 950°C.

[0017] Specifically, in step 3, the vibration frequency of the vibration table is 50-100 Hz, and the vibration wave is transmitted to the vanadium-infiltrated crucible through the refractory bricks.

[0018] Specifically, in step 3, the 880-950°C is the temperature measured by the crucible thermocouple in the vanadiumized crucible, and the temperature of the furnace body, the vanadiumized crucible and the furnace body have a temperature difference of 10-80°C in different time periods.

[0019] Specifically, in step 3, the specific method for determining the temperature of 880-950° C. is as follows: for taps with larger diameters, the upper limit vanadiumizing temperature is selected, and for taps with smaller diameters, the lower limit vanadiumizing temperature is selected.

[0020] The present invention also provides a device for preparing a dense thin vanadium-infiltrated layer on the surface of a tap by using the above method, comprising a vibration table, wherein: a furnace body is provided at the top of the vibration table, a vanadium-infiltrated crucible is placed in the furnace body, a vanadium-infiltrated crucible is filled with a vanadium-infiltrated agent for soaking the tap, the vanadium-infiltrated agent is made of the dense thin layer vanadium-infiltrated agent suitable for the surface of the tap, a furnace heating wire is provided on the inner wall of the furnace body, and a crucible thermocouple is inserted in the vanadium-infiltrated crucible.

[0021] Specifically, a furnace cover is provided on the top of the furnace body, and the vanadium-infiltrated crucible and the vibration table are connected by refractory bricks.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] The vanadiumizing agent of the present invention contains a carburizer and a catalyzer, which eliminates the problems of discontinuous vanadium layer and V2C content in the surface layer at 880-950°C in the traditional TD method. The vanadiumizing method of the present invention can be used to vanadate a micro tap made of HSS steel to obtain a dense VC layer of 1-4 μm, and the surface hardness is the highest, reaching Hv3000 or more. The tapping of the vanadiumized tap of the present invention is smooth, and the service life is increased by about 2 times. The vanadiumizing time is short, the productivity is high, the vanadiumizing temperature is low, and the service life of the vanadiumizing crucible is long. In addition, using HSS steel instead of HSSE as a tap also significantly reduces the material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1Schematic diagram of the structure of the infiltration device used in the embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the SEM morphology of the vanadium-infiltrated layer obtained on the HSS substrate in Example 1 of the present invention.

[0026] The numbers in the attached drawing are: crucible thermocouple 1; furnace top cover 2; furnace body 3; furnace heating wire 4; vanadiumizing agent 5; vanadiumizing crucible 6; tap 7; refractory brick 8; vibration table 9. DETAILED DESCRIPTION

[0027] The present invention further describes this embodiment in detail in conjunction with the accompanying drawings.

[0028] The invention discloses a dense thin layer vanadium infiltration agent for the surface of a tap, which comprises sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, boron carbide B4C, a carburizer, sodium fluoride NaF and a catalytic agent.

[0029] The content of sodium tetraborate Na2B4O7 of the present invention is 63.0-75.0wt%, the content of vanadium pentoxide V2O5 is 11-15wt%, the content of boron carbide powder B4C is 3.0-5.0wt%, the content of sodium fluoride NaF is 9-12wt%, the content of recarburizer is 2-4wt% and the content of catalyst is 0.6-1wt%.

[0030] Furthermore, the sodium tetraborate Na2B4O7 is 99wt.% borax and is calcined at 500°C for 20 minutes;

[0031] The catalyst is 99wt% nano powder; the recarburizer is 99% submicron powder; and the boron carbide B4C is 99% 100-150 mesh powder.

[0032] At the same time, the present invention also provides a method for preparing a dense thin vanadium-infiltrated layer on the surface of a tap by using the dense thin layer vanadium-infiltrated agent on the surface of a tap described in any of the above schemes, comprising the following steps.

[0033] Step 1: First weigh the recarburizer and catalyst powders according to the required ratio into a mechanical mixer, mix mechanically for 10 minutes, and then pour into the bottom of the vanadiumizing crucible 6.

[0034] Step 2: Weigh sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, sodium fluoride NaF and boron carbide powder B4C according to the ratio and put them into a mechanical mixer. After stirring and mixing for 20 minutes, first pour one-third of the mixed powder into the vanadiumizing crucible 6 to cover the carburizer and catalyst powder at the bottom, then place the tap 7 on the mixed powder, and finally pour the remaining mixed powder into the vanadiumizing crucible 6 to cover the miniature tap 7.

[0035] Step 3: Place the vanadiumizing crucible 6 in a furnace body 3 with a vibration table 9. The vibration of the vibration table 9 is transmitted to the vanadiumizing crucible 6 through the refractory bricks 8. After covering the furnace top cover 2, heat the furnace to a vanadiumizing temperature of 880-950°C at a heating rate of 5-7°C / min, start mechanical vibration, and vanadate for 120-240 minutes.

[0036] Step 4: After the vanadiumizing is completed, the heating power of the furnace body 3 is turned off, and the vibration of the vibration table 9 is stopped. When the temperature of the vanadiumizing crucible 6 drops to 800° C., the tap 7 is taken out and placed in a 10% sodium hydroxide NaOH solution and boiled for 15 minutes to remove the salt on the surface of the tap 7.

[0037] In step 1, the vanadiumizing crucible 6 can withstand temperatures above 1000°C. The vanadiumizing crucible 6 is made of a Fe55Ni30Cr15 high temperature alloy that can withstand vibration and impact, and can withstand more than 10 vanadiumizing cycles at 950°C.

[0038] In step 3 , the vibration frequency of the vibration table 9 is 50-100 Hz, and the vibration wave is transmitted to the vanadium-infiltrated crucible 6 through the refractory bricks 8 .

[0039] In step 3, the temperature of 880-950°C is measured by the crucible thermocouple 1 in the vanadiumized crucible 6, and the temperature of the furnace body 3 has a temperature difference of 10-80°C between the temperature of the vanadiumized crucible 6 and the temperature of the furnace body 3 in different time periods.

[0040] In step 3, the specific method for determining the temperature of 880-950° C. is as follows: for a tap 7 with a larger diameter, an upper limit vanadiumizing temperature is selected, and for a tap 7 with a smaller diameter, a lower limit vanadiumizing temperature is selected.

[0041] The vanadiumizing agent of the present invention contains a carburizer and a catalyzer, which eliminates the problems of discontinuous vanadium layer and V2C content in the surface layer of the traditional TD method at 880-950°C. The vanadiumizing method of the present invention is used to vanadate a micro-sized tap 7 made of HSS steel, and a dense VC layer of 1-4 μm can be obtained. The surface hardness is the highest, reaching Hv3000 or more. The vanadiumizing process of the present invention makes the tap 7 smooth and the service life is increased by about 2 times. The vanadiumizing time is short, the productivity is high, the vanadiumizing temperature is low, and the service life of the vanadiumizing crucible 6 is long. In addition, using HSS steel instead of HSSE as a tap also significantly reduces the material cost.

[0042] like Figure 1 As shown, the present invention also discloses a device for preparing a dense thin vanadium-infiltrated layer on the surface of a tap by using the above method, comprising a vibration table 9, wherein: a furnace body 3 is provided at the top of the vibration table 9, a vanadium-infiltrated crucible 6 is placed in the furnace body 3, a vanadium-infiltrated crucible 6 is filled with a vanadium-infiltrated agent 5 for soaking a tap 7, a furnace heating wire 4 is provided on the inner wall of the furnace body 3, and a crucible thermocouple 1 is inserted in the vanadium-infiltrated crucible 6.

[0043] Specifically, a furnace top cover 2 is provided at the top of the furnace body 3 , and the vanadium-infiltrated crucible 6 and the vibration table 9 are connected by refractory bricks 8 .

[0044] Figure 2 The SEM morphology of the vanadium-infiltrated layer obtained on the HSS substrate in Example 1 of the present invention shows that the thickness of the vanadium-infiltrated layer at 900°C+120min is 1.8μm, the infiltrated layer is dense, and no obvious holes and loose layers are found on the surface. The hardness reaches HV3100.

[0045] The present invention is further illustrated by the following examples.

[0046] Example 1: Vanadium is applied to the surface of an M2 small tap made of HSS steel.

[0047] (1) A Φ100×120 mm vanadium-infiltrated crucible 6 is made of high-temperature alloy Ni30. The wall thickness of the vanadium-infiltrated crucible 6 is 10 mm. The volume of the vanadium-infiltrated crucible 6 is about 500 ml. The crucible is baked in a 120° C. drying furnace for 20 min to remove surface adsorbed moisture.

[0048] (2) Use a balance to weigh 15 g of recarburizer powder and 4 g of catalyzer powder into a mechanical mixer. After mechanical mixing for 10 minutes, pour them into the bottom of the crucible.

[0049] (3) Use a balance to weigh 20 g of boron carbide B4C, 50 g of sodium fluoride NaF, 65 g of vanadium pentoxide V2O5 and 346 g of sodium tetraborate Na2B4O7 into a mechanical mixer. After mechanical mixing for 20 min, pour one third of the mixture into a crucible to cover the powder in step (2).

[0050] (4) Place 10 to 20 M2 small taps flat on the surface of the mixed powder in the vanadium-infiltrated crucible 6, then pour in the remaining mixed powder and cover the taps 7. Then place the vanadium-infiltrated crucible 6 in a furnace body 3 containing a mechanical vibration table. The vibration of the vibration table 9 is transmitted to the vanadium-infiltrated crucible 6 through the refractory bricks 8.

[0051] (5) The upper furnace cover 2 is heated to a vanadiumizing temperature of 900°C at a heating rate of 5-7°C / min, and mechanical vibration is turned on for vanadiumizing for 120 minutes.

[0052] (6) After the vanadiumization is completed, turn off the heating power of the furnace body 3 and stop the vibration of the vanadiumization crucible 6. When the temperature of the vanadiumization crucible 6 drops to 800°C, take out the tap and put it into a 10% sodium hydroxide NaOH solution and boil it for 15 minutes to remove the salt on the surface of the tap.

[0053] The SEM morphology of the vanadium-infiltrated layer obtained on the M2 tap made of HSS steel in this example is as follows: Figure 2As shown, the thickness of the vanadium-diffused layer at 900℃+120min is 1.8μm, the vanadium-diffused layer is dense, no obvious holes and loose layers are found on the surface, and the hardness reaches HV3100.

[0054] Example 2: Vanadiumizing the surface of an M6 tap made of HSS steel.

[0055] (1) Use Ni30 high temperature alloy to make a Φ100×120mm crucible with a wall thickness of 10mm and a volume of approximately 500ml. Bake it in a 120℃ drying furnace for 20min to remove surface adsorbed moisture.

[0056] (2) Use a balance to weigh 20g of recarburizer powder and 5g of catalyzer powder into a mechanical mixer. After mechanical mixing for 10 minutes, pour them into the bottom of the crucible.

[0057] (3) Use a balance to weigh 25 g of boron carbide B4C, 60 g of sodium fluoride NaF, 75 g of vanadium pentoxide V2O5 and 315 g of sodium tetraborate Na2B4O7 into a mechanical mixer. After mechanical mixing for 20 min, pour one third of the mixture into the vanadium-infiltrated crucible 6 to cover the powder in step (2).

[0058] (4) Place 10 to 15 M6 taps flat on the surface of the mixed powder in the vanadium-infiltrated crucible 6, then pour in the remaining mixed powder and cover the taps. Then place the vanadium-infiltrated crucible 6 in a furnace body 3 containing a mechanical vibration table. The vibration of the vibration table 9 is transmitted to the vanadium-infiltrated crucible 6 through the refractory bricks 8.

[0059] (5) The upper furnace cover 2 is heated to a vanadiumizing temperature of 950°C at a heating rate of 5-7°C / min, and mechanical vibration is turned on for vanadiumizing for 240 minutes.

[0060] (6) After the vanadiumization is completed, turn off the heating power of the furnace body and stop the vibration of the vanadiumization crucible 6. When the temperature of the vanadiumization crucible 6 drops to 800°C, take out the tap and put it into a 10% sodium hydroxide NaOH solution and boil it for 15 minutes to remove the salt on the surface of the tap.

[0061] In this embodiment, the thickness of the vanadium-infiltrated layer obtained on the M6 ​​tap made of HSS steel is 3.8 μm, the infiltrated layer is dense, no obvious holes and loose layers are found on the surface, and the hardness reaches HV3100.

[0062] Example 3: Vanadiumizing the surface of M1 micro taps made of HSS steel:

[0063] Step 1: Use high temperature alloy Ni30 to make a Φ100×120mm vanadium-infiltrated crucible 6, the wall thickness of the vanadium-infiltrated crucible 6 is 10mm, the volume of the vanadium-infiltrated crucible 6 is about 500ml, and bake it in a 120°C drying furnace for 20 minutes to remove surface adsorbed moisture.

[0064] Step 2: Use a balance to weigh 10 g of recarburizer powder and 3 g of catalyzer powder into a mechanical mixer, mix mechanically for 10 minutes, and then pour into the vanadiumizing crucible 6.

[0065] Step 3: Use a balance to weigh 15 g of boron carbide B4C, 45 g of sodium fluoride NaF, 55 g of vanadium pentoxide V2O5 and 372 g of sodium tetraborate Na2B4O7 into a mechanical mixer. After mechanical mixing for 20 minutes, pour one third of them into a crucible and cover the powder in step 2.

[0066] Step 4: Place 10 to 20 M1 small taps flat on the surface of the mixed powder in the crucible, then pour in the remaining mixed powder and cover the taps, then place the crucible in the furnace body 3 containing a mechanical vibration table, and the vibration of the vibration table is transmitted to the crucible through the refractory bricks.

[0067] Step 5: The furnace top cover is closed, and the temperature is raised to 880°C vanadiumizing temperature at a heating rate of 5-7°C / min, and mechanical vibration is turned on, and vanadiumizing is carried out for 120 minutes.

[0068] Step 6: After the vanadiumization is completed, turn off the heating power of the furnace body 3 and stop the vibration of the vanadiumization crucible 6. When the temperature of the vanadiumization crucible 6 drops to 800°C, take out the tap and put it into a 10% sodium hydroxide NaOH solution and boil it for 15 minutes to remove the salt on the surface of the tap.

[0069] In this embodiment, the vanadium-diffused layer obtained on the M1 tap made of HSS steel is 1.1 μm, the vanadium-diffused layer is dense, no obvious holes and loose layers are found on the surface, and the hardness reaches HV3100.

[0070] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A dense thin layer vanadiumizing agent for the surface of a tap, characterized by: The invention comprises sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, boron carbide B4C, a recarburizer, sodium fluoride NaF and a catalyst, wherein the content of sodium tetraborate Na2B4O7 is 63.0-75.0wt%, the content of vanadium pentoxide V2O5 is 11-15wt%, the content of boron carbide powder B4C is 3.0-5.0wt%, the content of sodium fluoride NaF is 9-12wt%, the content of the recarburizer is 2-4wt% and the content of the catalyst is 0.6-1 wt%.

2. The dense thin layer vanadiumizing agent for the tap surface according to claim 1, characterized in that: The sodium tetraborate Na2B4O7 is prepared by calcining 99wt% borax at 500°C for 20 minutes; The catalyst is 99wt% nano powder; the recarburizer is 99% submicron powder; and the boron carbide B4C is 99% 100-150 mesh powder.

3. A method for preparing a dense thin vanadium-infiltrated layer on a tap surface by using the dense thin layer vanadium-infiltrated agent for tap surface according to any one of claims 1 to 2, comprising the following steps: Step 1: First, weigh the carburizer and catalyst powders according to the required ratio into a mechanical mixer, mix mechanically for 10 minutes, and then pour into the bottom of the vanadiumizing crucible (6); Step 2: Weigh sodium tetraborate Na2B4O7, vanadium pentoxide V2O5, sodium fluoride NaF and boron carbide powder B4C according to the ratio and put them into a mechanical mixer. After stirring and mixing for 20 minutes, pour one third of the mixed powder into the vanadiumizing crucible (6) to cover the carburizer and catalyst powder at the bottom, then place the tap (7) on the mixed powder, and finally pour the remaining mixed powder into the vanadiumizing crucible (6) to cover the micro tap (7); Step 3: placing the vanadizing crucible (6) in a furnace body (3) with a vibration table (9), transmitting the vibration of the vibration table (9) to the vanadizing crucible (6) through the refractory bricks (8), covering the furnace top cover (2), heating the furnace at a heating rate of 5-7°C / min to a vanadizing temperature of 880-950°C, turning on mechanical vibration, and vanadizing for 120-240min; Step 4: After the vanadiumization is completed, the heating power of the furnace body (3) is turned off, and the vibration of the vibration table (9) is stopped. When the temperature of the vanadiumizing crucible (6) drops to 800° C., the tap (7) is taken out and placed in a 10% sodium hydroxide NaOH solution and boiled for 15 minutes to remove salt from the surface of the tap (7).

4. The method for preparing a dense thin vanadium-infiltrated layer on the surface of a tap according to claim 3, characterized in that: In step 1, the vanadiumizing crucible (6) is capable of withstanding temperatures above 1000° C. The vanadiumizing crucible (6) is made of a Fe55Ni30Cr15 high temperature alloy capable of withstanding vibration and impact, and can withstand a vanadiumizing life of more than 10 times at 950° C.

5. The method for preparing a dense thin vanadium-infiltrated layer on the surface of a tap according to claim 3, characterized in that: In step 3, the vibration frequency of the vibration table (9) is 50-100 Hz, and the vibration wave is transmitted to the vanadium-infiltrated crucible (6) through the refractory bricks (8).

6. The method for preparing a dense thin vanadium-infiltrated layer on the surface of a tap according to claim 3, characterized in that: In step 3, the temperature of 880-950° C. is measured by the crucible thermocouple (1) in the vanadium-infiltrated crucible (6), while the temperature of the furnace body (3) has a temperature difference of 10-80° C. between the temperatures of the vanadium-infiltrated crucible (6) and the furnace body (3) in different time periods.

7. The method for preparing a dense thin vanadium-infiltrated layer on the surface of a tap according to claim 6, characterized in that: In step 3, the specific method for determining the temperature of 880-950° C. is as follows: for a tap (7) with a larger diameter, an upper limit vanadiumizing temperature is selected, and for a tap (7) with a smaller diameter, a lower limit vanadiumizing temperature is selected.

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