A steel wire wool welding method of an exhaust gas aftertreatment device

Abstract

The present application relates to the technical field of vehicle exhaust treatment, and particularly relates to a steel wool welding method of an exhaust aftertreatment device, which comprises the following steps: S1, steel wool and sleeve spare parts are prepared and cleaned, solder paste is diluted with water to prepare solder; S2, the steel wool is soaked in the solder, so that the solder is coated on the surface of the steel wool; S3, the steel wool is taken out from the solder, and the steel wool is placed for shade drying; S4, the steel wool is preheated, and the water in the solder on the surface of the steel wool is dried; S5, the steel wool is loaded into the sleeve, and the steel wool is placed in a vacuum furnace, and the solder on the surface of the steel wool is heated and melted; S6, the steel wool is cooled, so that the solder on the surface of the steel wool is solidified, and the steel wool is welded with the inner wall of the sleeve. The present application can make the steel wool have a certain rigidity through a welding process, so that the deformation of the steel wool during installation or work does not cause uneven gaps and affect the reaction of the exhaust gas and urea.

Description

Technical Field

[0001] This invention relates to the technical field of vehicle exhaust gas treatment, and in particular to a method for welding steel wool into an exhaust gas aftertreatment device. Background Technology

[0002] In the exhaust gas aftertreatment device, urea reacts with the exhaust gas to remove nitrogen oxides and reduce pollution from exhaust emissions.

[0003] In existing technologies, steel wool is installed in the mixing pipe of exhaust gas aftertreatment devices. This steel wool has a 3D porous or multi-void structure. During operation, exhaust gas and urea droplets pass through the steel wool, causing the urea droplets to settle on its surface and within the wool, resulting in thorough mixing and breaking down of the exhaust gas and urea. The small diameter and complex pore structure of the steel wool, along with its large heat transfer area, facilitates sufficient heat exchange between the urea droplets and the exhaust gas, thereby promoting evaporation and pyrolysis of the urea droplets and improving resistance to crystallization.

[0004] In existing technologies, because steel wool is generally flexible, it is easy for the steel wool to deform under external force or exhaust gas pressure during the installation and use of exhaust gas aftertreatment devices, resulting in uneven distribution of the steel wool's pores and affecting the reaction effect. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a steel wool welding method for exhaust gas aftertreatment devices. This method can make the steel wool have a certain rigidity through the welding process, so as to avoid uneven gaps caused by deformation of the steel wool during installation or operation, which would affect the reaction between exhaust gas and urea.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] This invention provides a method for welding steel wool into an exhaust gas aftertreatment device, the method comprising:

[0008] S1. Clean the steel wool and sleeve parts, and dilute the solder paste with water to prepare the solder.

[0009] S2. Immerse the steel wool in the solder so that the surface of the steel wool is coated with the solder;

[0010] S3. Remove the steel wool from the solder and let it air dry in the shade;

[0011] S4. Preheat the steel wool and dry the moisture in the solder on the surface of the steel wool;

[0012] S5. The steel wool is loaded into the sleeve, and the steel wool and the sleeve are placed in a vacuum furnace to heat and melt the solder on the surface of the steel wool;

[0013] S6. Cool the steel wool to solidify the solder on the surface of the steel wool, and weld the steel wool to the inner wall of the sleeve.

[0014] Further, in S1, the solder paste is a nickel-based solder paste, and the nickel-based solder paste is mixed with the purified water and stirred evenly; the composition of the solder is: by weight, the ratio of purified water to nickel-based solder paste is 2:4.

[0015] Furthermore, in S2, the steel wool is immersed in the solder for a first set time t1, where 3min≤t1≤8min.

[0016] Furthermore, S2 includes:

[0017] S21. The steel wool is placed in a leaky container, the leaky container having a hole for the solder to flow into and out of the leaky container;

[0018] S22, The leaky container and the steel wool are simultaneously immersed in the solder.

[0019] Furthermore, the bottom plate of the leaky container can be opened and closed, or the bottom plate of the leaky container can be detached.

[0020] Furthermore, S3 includes:

[0021] S31. Remove the steel wool from the solder;

[0022] S32. Place the steel wool on a support; wherein the support has at least three support points, the support points being supported on the bottom of the steel wool;

[0023] S33, the steel wool is placed on the support to air dry for a second set time t2.

[0024] Furthermore, the second set time t2 for the steel wool to be placed in the shade to dry satisfies: 15min≤t2≤60min.

[0025] Furthermore, in S4, the temperature for preheating the steel wool is a first set temperature T1, and the preheating time for the steel wool is a third set time t3, wherein 90℃≤T1≤180℃ and 20min≤t3≤60min.

[0026] Furthermore, after the vacuum furnace is heated to the second set temperature T2, the steel wool is heated for a fourth set time t4, where 1000℃≤T2≤1200℃ and 1h≤t4≤1.5h.

[0027] Furthermore, S6 includes:

[0028] S61. After the vacuum furnace stops heating, the steel wool is cooled to the cooling temperature tc inside the vacuum furnace;

[0029] S62. Remove the steel wool from the vacuum furnace and allow it to cool naturally to room temperature.

[0030] Furthermore, in S61, argon gas is introduced into the vacuum furnace while the steel wool is being cooled in the vacuum furnace.

[0031] Furthermore, the steel wool welding method further includes:

[0032] S7. The press applies a set pressure to the steel wool, measures the shrinkage stroke of the steel wool, and tests the steel wool's resistance to deformation.

[0033] In summary, the present invention has the following beneficial effects:

[0034] 1. In the steel wool welding method of the present invention, the solder is prepared by diluting solder paste with pure water to reduce the viscosity of the solder, making it easier for the solder to flow into the pores of the steel wool and coat the surface of the steel wool. During solder coating, the steel wool is immersed in the solder, allowing the solder to coat as much as possible on the surface of all the steel wires, improving the effect after solder curing. After the steel wool is coated with solder, it is removed from the solder and air-dried. Due to the surface tension of water, the solder that was blocked in the pores of the steel wool drips off under its own weight, thus preventing the solder in the pores from blocking the pores after welding curing and affecting the exhaust gas treatment capacity of the steel wool. After the steel wool is air-dried, the moisture in the solder on the surface of the steel wool is dried by preheating, preventing the evaporation of residual moisture during soldering from causing uneven welding surfaces. After preheating and drying, the steel wool is placed in a vacuum furnace. The vacuum furnace is heated to the melting temperature of the solder, so that the solder melts and coats the surface of the steel wool. After the steel wool cools, the solder solidifies on the surface of the steel wool. The solidified solder enhances the rigidity of the steel wool. During transportation, disassembly and operation, the steel wool is not easily deformed by external forces, so that the voids in the steel wool are kept evenly distributed, ensuring the reaction effect of the exhaust gas during exhaust gas treatment.

[0035] 2. When immersing steel wool in solder, a funnel-type container is used to hold the steel wool. This eliminates the need to clamp the steel wool during immersion or removal from the solder, reducing deformation and ensuring effective solder coating on the surface. Furthermore, one funnel-type container can hold multiple steel wool samples, allowing for solder coating on multiple surfaces in a single immersion. This reduces the number of required fixtures and improves the efficiency of solder coating on steel wool.

[0036] 3. When the steel wool is placed to air dry, it is stably supported on the support by at least three fulcrums. The bottom part of the steel wool, which is offset from the fulcrums, is suspended above the support. The dripping solder will not accumulate at the bottom of the steel wool, thus avoiding the bottom of the steel wool from being soaked in the solder that flows down by its own weight, which would cause the solder to block the gaps at the bottom of the steel wool.

[0037] 4. After the vacuum furnace stops heating, the steel wool is first cooled to a lower temperature tc inside the vacuum furnace to avoid oxidation of the steel wool when it is taken out at a high temperature. Then the steel wool is taken out of the vacuum furnace and cooled naturally.

[0038] 5. When the steel wool is cooled in the vacuum furnace, argon gas is introduced into the vacuum furnace. The argon gas protects the steel wool and reduces the probability of product oxidation due to heat. At the same time, during the cooling process, the argon gas filling the vacuum furnace acts as a heat transfer medium, which makes the temperature distribution in the vacuum furnace more uniform and the welding effect of the steel wool better. Attached Figure Description

[0039] Figure 1 This is a three-dimensional structural diagram of steel wool according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic flowchart of a steel wool welding method according to an embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the structure of steel wool and a leaky container according to an embodiment of the present invention.

[0042] Figure 4 This is a schematic diagram of the steel wool and support structure according to an embodiment of the present invention.

[0043] In the picture:

[0044] 100, steel wool; 200, solder; 300, leaky container; 310, leak hole; 400, support; 500, sleeve. Detailed Implementation

[0045] The invention will now be further described with reference to the accompanying drawings.

[0046] This embodiment provides a method for welding steel wool into an exhaust gas aftertreatment device, referring to... Figure 1 In this embodiment, the steel wool 100 is formed by winding steel wire and is cylindrical in shape. The steel wool 100 has multiple gaps for gas to flow through. When using the steel wool 100, it is fixedly installed in a cylindrical sleeve 500, and then the sleeve 500 and the steel wool 100 are placed in the mixing pipe of the exhaust gas aftertreatment device for exhaust gas treatment.

[0047] Reference Figures 2 to 4 The steel wool welding method in this embodiment includes:

[0048] S1. Spare parts: steel wool 100 and sleeve 500. After cleaning the steel wool 100 and sleeve 500, set them aside for later use. Dilute the solder paste with water to prepare solder 200.

[0049] In this embodiment, solder 200 is prepared by diluting solder paste with water to reduce the viscosity of solder 200, so that solder 200 can flow into the gaps of steel wool 100 and coat the surface of steel wool 100.

[0050] The solder paste is a nickel-based solder paste. The nickel-based solder paste is mixed with purified water and stirred thoroughly before use. Purified water is used for mixing to reduce impurities in the prepared solder and ensure welding performance. Alternatively, in other embodiments, other suitable solder pastes may be used.

[0051] In this embodiment, the composition of solder 200 is as follows: by weight, the ratio of pure water to nickel-based solder paste is 2:4. It has been verified that under this ratio, the solder 200 can be uniformly coated on the surface of steel wool 100, and the deformation resistance of steel wool 100 after soldering meets the requirements.

[0052] S2. Immerse the steel wool 100 in solder 200 so that the surface of the steel wool 100 is coated with solder 200.

[0053] S2 includes:

[0054] S21. Steel wool 100 is placed in a leak container 300, which has a leak hole 310 for solder 200 to flow in and out of the leak container 300.

[0055] S22, the leak container 300 and the steel wool 100 are simultaneously immersed in the solder 200. The solder 200 enters the leak container 300 and covers the steel wool 100, so that the surface of the steel wool 100 is coated with the solder 200.

[0056] Reference Figure 3 In this embodiment, the steel wool 100 is immersed in the solder 200, allowing the solder 200 to coat all the steel wire surfaces of the steel wool 100 as much as possible, thus improving the effect of the solder 200 after welding and curing. By using a funnel container 300 to hold the steel wool 100, there is no need to clamp the steel wool 100 during the process of immersing it in or removing it from the solder 200, reducing deformation during clamping and ensuring the effective coating of the steel wool 100 with the solder 200. Furthermore, one funnel container 300 can hold multiple steel wool 100s, allowing for solder 200 coating on multiple steel wool 100 surfaces in a single immersion, reducing the number of required clamps and improving the processing efficiency of coating the steel wool 100 with the solder 200.

[0057] In addition, in other embodiments, other clamps may be used to pick up and put down the steel wool 100 in the solder 200.

[0058] In this embodiment, the steel wool 100 is immersed in the solder 200 for a first set time t1, where 3 min ≤ t1 ≤ 8 min. The steel wool 100 is immersed in the solder 200, which has a pure water to nickel-based solder paste ratio of 2:4, for 3 min to 8 min to ensure that the solder 200 penetrates into every gap of the steel wool 100 and coats its surface. Preferably, in this embodiment, the first set time t1 for immersing the steel wool 100 in the solder 200 is 5 min.

[0059] Furthermore, in other embodiments, when the composition of solder 200 changes, the first set time t1 for immersing steel wool 100 in solder 200 can also be other suitable values. For example, when the ratio of pure water to nickel-based solder paste in solder 200 is less than 2:4, the viscosity of solder 200 increases, and the first set time t1 for immersing steel wool 100 in solder 200 can be appropriately increased to ensure the coating effect of solder 200.

[0060] S3. Remove the steel wool 100 from the solder 200 and place the steel wool 100 to air dry.

[0061] S3 includes:

[0062] S31. Remove steel wool 100 from solder 200.

[0063] In this embodiment, since the steel wool 100 is placed in the leak-type container 300, the steel wool 100 can be removed by clamping it in the solder 200 and taking out the leak-type container 300. This avoids the deformation of the steel wool 100 or the unevenness of the solder 200 on the surface of the steel wool 100 at the clamping point caused by directly clamping the steel wool 100.

[0064] The bottom plate of the leaky container 300 can be opened and closed, or the bottom plate of the leaky container 300 can be detached. Therefore, after the leaky container 300 is removed from the solder 200, the steel wool 100 can be removed from the leaky container 300 by opening or removing the bottom plate of the leaky container 300, which facilitates the further processing of the steel wool 100.

[0065] S32. Place the steel wool 100 on a support 400 and support the steel wool 100 through the support 400.

[0066] Reference Figure 4 In this embodiment, the support 400 is provided with at least three non-collinear fulcrums protruding upwards, and the fulcrums are supported on the bottom of the steel wool 100.

[0067] S33, steel wool 100 is placed on support 400 to air dry for a second set time t2.

[0068] After the steel wool 100 is coated with solder 200, it is removed from the solder 200 and air-dried. The solder 200 in the steel wool 100, which is sealed in the gaps due to the surface tension of water, drips off under its own weight, thereby preventing the solder 200 in the gaps from blocking the gaps after the welding solidifies and affecting the exhaust gas treatment capacity of the steel wool 100.

[0069] In this embodiment, since the steel wool 100 is stably supported on the support 400 by at least three fulcrums, the part of the bottom of the steel wool 100 that is offset from the fulcrums is suspended above the support 400, which reduces the contact area between the support 400 and the steel wool 100, and at the same time avoids the bottom of the steel wool 100 from being immersed in the solder 200 that flows down by its own weight, causing the solder 200 to block the gap at the bottom of the steel wool 100.

[0070] In this embodiment, the second set time for air-drying the steel wool 100 is t2, where t2 satisfies: 15min ≤ t2 ≤ 60min. Preferably, at room temperature (25℃), the second set time t2 for air-drying the steel wool 100 is 30min.

[0071] Preferably, when the steel wool 100 is placed to air dry, a fan can be used to create convection from top to bottom, which can accelerate the dripping speed of the solder 200 sealing the gaps in the steel wool 100.

[0072] S4. Preheat steel wool 100 and dry the moisture in the solder 200 on the surface of steel wool 100.

[0073] In this embodiment, after the steel wool 100 is air-dried, the moisture in the solder 200 on the surface of the steel wool 100 is dried by preheating, which prevents the evaporation of residual moisture during soldering and avoids uneven welding surfaces. Since drying does not require excessively high temperatures, an electric oven can be used to preheat the steel wool 100 in this embodiment. In other embodiments, other heating devices can also be used to preheat the steel wool 100.

[0074] In this embodiment, the temperature for preheating the steel wool 100 is a first set temperature T1, and the preheating time is a third set time t3, wherein 90℃≤T1≤180℃, and 20min≤t3≤60min. Preferably, the first set temperature T1 is 120℃, and the third set time t3 is 30min, to ensure that the moisture content in the solder 200 on the surface of the steel wool 100 is reduced to a level that does not easily affect the welding effect of the solder 200.

[0075] S5. Insert the steel wool 100 into the sleeve 500, and place the steel wool 100 and the sleeve 500 into a vacuum furnace to heat and melt the solder 200 on the surface of the steel wool 100.

[0076] S5 includes:

[0077] S51. Insert steel wool 100 into sleeve 500. Steel wool 100 and sleeve 500 are coaxially arranged, and the outer periphery of steel wool 100 is in contact with the inner wall of sleeve 500. Vacuum furnace is evacuated for the first time to achieve the first vacuum degree P1. Steel wool 100 and sleeve 500 are then placed into vacuum furnace at the same time.

[0078] S52. While the vacuum furnace heats the steel wool 100, it is simultaneously evacuated to a second vacuum level P2. The vacuum furnace is heated to the melting temperature of the solder 200, causing the solder 200 to melt and coat the surface of the steel wool 100.

[0079] Among them, the second vacuum degree P2 is higher than the first vacuum degree P1, that is, the absolute gas pressure inside the vacuum furnace after the second vacuuming is less than the absolute gas pressure inside the vacuum furnace after the first vacuuming.

[0080] In this embodiment, the vacuum furnace is evacuated using a secondary vacuuming method. Before the steel wool 100 is placed into the vacuum furnace, the vacuum furnace is evacuated to a first vacuum level P1 and maintained at pressure. This allows the vacuum furnace to be evacuated when it is idle, reducing the waiting time for the vacuum furnace to be evacuated and improving the processing efficiency of the steel wool 100.

[0081] After the steel wool 100 is placed in the vacuum furnace, the vacuum degree of the furnace reaches the first vacuum degree P1, which has a certain antioxidant effect on the steel wool. At this point, heating of the steel wool 100 can begin, while the vacuum furnace undergoes a second vacuuming. When the vacuum furnace first starts heating, the vacuum degree inside the furnace is close to the first vacuum degree P1, which is relatively low, but the temperature inside the vacuum furnace is also low, reducing the risk of thermal oxidation of the steel wool 100. As the vacuum furnace heats up, the vacuum degree inside gradually increases until it reaches the second vacuum degree, making the steel wool 100 less susceptible to thermal oxidation. Therefore, in this embodiment, by performing a second vacuuming during the heating process of the vacuum furnace, the time spent waiting for the second vacuuming is eliminated, further improving the processing efficiency of the steel wool 100.

[0082] In addition, in other embodiments, the vacuum furnace may be evacuated to a second vacuum level P2 before being heated.

[0083] In this embodiment, the first vacuum level P1 ≥ 0.08 MPa and the second vacuum level P2 ≥ 0.1 MPa. Furthermore, in other embodiments, the first vacuum level P1 and the second vacuum level P2 can be set according to actual processing requirements.

[0084] In this embodiment, when the vacuum furnace heats the steel wool 100, the temperature inside the furnace rises to the second set temperature T2 within 8-10 hours. During this process, the vacuum degree inside the vacuum furnace increases from P1 to P2. Subsequently, the vacuum furnace maintains the steel wool 100 at the second set temperature T2 for a fourth set time t4. Where 1000℃≤T2≤1200℃, 1h≤t4≤1.5h, the solder 200 coated on the surface of the steel wool 100 is completely melted.

[0085] S6. Cool the steel wool 100 to solidify the solder 200 on the surface of the steel wool 100.

[0086] S6 includes:

[0087] S61. After the vacuum furnace stops heating, the steel wool 100 is cooled to the cooling temperature tc inside the vacuum furnace.

[0088] After the vacuum furnace stops heating, argon gas is introduced into the vacuum furnace. As the steel wool 100 cools down with the vacuum furnace, the argon gas protects the steel wool 100, reducing the probability of product oxidation due to heat. At the same time, during the cooling process, the argon gas filling the vacuum furnace acts as a heat transfer medium, making the temperature distribution in the vacuum furnace uniform and the steel wool 100 cools down evenly, resulting in better welding effect of the surface solder 200 on the steel wool 100.

[0089] In this embodiment, the argon gas is 99.99% pure argon gas. Furthermore, in other embodiments, other suitable protective gases may be used instead of the 99.99% pure argon gas used in this embodiment.

[0090] In this embodiment, tc is specifically ≤500℃. The steel wool 100 is first cooled to a lower temperature tc in the vacuum furnace to avoid oxidation of the steel wool 100 when it is directly removed at a high temperature, and also to make the removal of the steel wool 100 safer. After the steel wool 100 is cooled to tc, the argon gas filling into the vacuum furnace is stopped.

[0091] S62. Remove steel wool 100 from the vacuum furnace and allow it to cool naturally to room temperature.

[0092] After the steel wool 100 cools, the solder 200 solidifies on its surface. The solidified solder 200 enhances the rigidity of the steel wool 100, preventing it from deforming under external forces during transportation, disassembly, and operation. This ensures a uniform distribution of voids within the steel wool 100, guaranteeing the effective reaction of the exhaust gas during treatment. Simultaneously, the solder 200 welds the steel wool 100 and the sleeve 500 together, achieving a secure connection between them.

[0093] S7. The press applies pressure to the steel wool 100, measures the shrinkage stroke of the steel wool 100, and tests the deformation resistance of the steel wool 100.

[0094] S7 includes:

[0095] S71. The press applies pressure to the steel wool 100, and the steel wool 100 contracts its stroke under the pressure of the press.

[0096] S72. Measure the shrinkage stroke of steel wool 100, and determine whether steel wool 100 is qualified based on the shrinkage stroke of steel wool 100 and the pressure of the press.

[0097] Specifically, in this embodiment, when the press provides a pressure of 300N, the maximum shrinkage stroke of the steel wool 100 does not exceed 1mm; and when the shrinkage stroke of the steel wool 100 reaches 12mm, the pressure provided by the press is not less than 1500N, which means that the deformation resistance of the steel wool 100 is considered to be qualified.

[0098] In this embodiment, the press is specifically a pneumatic press. However, in other embodiments, the press may also be a hydraulic press or other suitable press.

[0099] In some embodiments, the steel wool welding method further includes:

[0100] S8. Inspect the voids in the steel wool 100.

[0101] S8 includes:

[0102] S81. Place steel wool 100 coaxially inside a test tube, with the periphery of steel wool 100 abutting against the inner wall of the test tube.

[0103] S82. Pressurized gas is introduced from the first end of the detection tube. After passing through the gaps of the steel wool 100, the pressurized gas flows out from the second end of the detection tube.

[0104] S83. Measure the air pressure N1 at the first end of the detection tube and the air pressure N2 at the second end of the detection tube. When N1-N2≤δN, the porosity of the steel wool 100 is considered to meet the usage requirements. Here, δN is the set pressure difference value, which can be set according to the requirements of the finished steel wool 100 product.

[0105] The above are merely preferred embodiments of the present invention. Therefore, all equivalent changes or modifications made in accordance with the structure, features and principles of the present invention patent application are included within the scope of the present invention patent application.

Claims

1. A method for welding steel wire wool into an exhaust gas aftertreatment device, characterized in that, The steel wool welding method includes: S1, steel wool (100) and sleeve (500) spare parts are cleaned, and solder paste is diluted with water to prepare solder (200); S2. Immerse the steel wool (100) in the solder (200) so that the surface of the steel wool (100) is coated with the solder (200); S3. Remove the steel wool (100) from the solder (200) and place the steel wool (100) to air dry; S4. Preheat the steel wool (100) and dry the moisture in the solder (200) on the surface of the steel wool (100); S5. The steel wool (100) is inserted into the sleeve (500), and the steel wool (100) and the sleeve (500) are placed in a vacuum furnace to heat and melt the solder (200) on the surface of the steel wool (100). S6. Cool the steel wool (100) so that the solder (200) on the surface of the steel wool (100) solidifies and the steel wool (100) is welded to the inner wall of the sleeve (500).

2. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, In S1, the solder paste is a nickel-based solder paste, which is mixed with pure water and stirred evenly; the composition of the solder (200) is as follows: by weight, the ratio of pure water to nickel-based solder paste is 2:

4.

3. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, In S2, the steel wool (100) is immersed in the solder (200) for a first set time t1, where 3min≤t1≤8min.

4. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1 or 3, characterized in that, S2 include: S21. The steel wool (100) is placed in a leaky container (300), the leaky container (300) having a leak hole (310) for the solder (200) to flow into and out of the leaky container (300); S22, the leaky container (300) and the steel wool (100) are simultaneously immersed in the solder (200).

5. The steel wool welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, S3 include: S31. Remove the steel wool (100) from the solder (200); S32. The steel wool (100) is placed on a support (400); wherein the support (400) has at least three support points, which are supported on the bottom of the steel wool (100); S33, the steel wool (100) is placed on the support (400) and air-dried for a second set time t2.

6. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1 or 5, characterized in that, The second set time t2 for the steel wool (100) to be placed in the shade to dry satisfies: 15min≤t2≤60min.

7. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, In S4, the temperature for preheating the steel wool (100) is the first set temperature T1, and the time for preheating the steel wool (100) is the third set time t3, wherein 90℃≤T1≤180℃ and 20min≤t3≤60min.

8. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, After the vacuum furnace is heated to the second set temperature T2, the steel wool (100) is heated for a fourth set time t4, where 1000℃≤T2≤1200℃ and 1h≤t4≤1.5h.

9. The steel wool welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, S6 include: S61. After the vacuum furnace stops heating, the steel wool (100) is cooled to the cooling temperature tc inside the vacuum furnace; S62. Remove the steel wool (100) from the vacuum furnace and allow it to cool naturally to room temperature.

10. The steel wire welding method for an exhaust gas aftertreatment device as described in claim 1, characterized in that, The steel wool welding method further includes: S7. The press applies pressure to the steel wool (100), measures the shrinkage stroke of the steel wool (100), and tests the deformation resistance of the steel wool (100).

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