Novel preparation method of pressing wheel for large-scale automatic wood-working machine

Abstract

The invention relates to the technical field of wood-working mechanical equipment manufacturing, and discloses a novel preparation method of a pressing wheel for large-scale automatic wood-working machinery, a 45 steel round bar material is adopted, the material is subjected to primary machining after blanking to obtain a primary workpiece, and the obtained primary workpiece is put into an atmosphere protection heat treatment furnace to be subjected to pre-heat treatment; a primary workpiece subjected to heat treatment in advance is machined and finely machined through a high-precision machine tool, an inner hole needs to be enlarged in advance, allowance is reserved in the inner hole of the primary workpiece, a secondary workpiece is obtained after machining, then the secondary workpiece directly enters a gas co-permeation furnace, the pressing wheel is obtained after treatment, and the pressing wheel is discharged out of the furnace and cooled in air. And putting the pressing wheel into a sealed furnace, introducing nitrogen, ammonia gas and a beautifying agent, heating, and cooling in air after treatment. The production process is free of emission of three wastes, environmentally friendly, easy to operate and low in cost, and the surface hardness, wear resistance and corrosion resistance are far higher than those of technical index requirements.

Description

Technical Field

[0001] The invention relates to the technical field of woodworking machinery equipment manufacturing, and more particularly to a novel preparation method of a pressing wheel for large-scale automated woodworking machinery. Background Art

[0002] The pressing wheel in large woodworking machinery and equipment requires not only high surface hardness, but also anti-corrosion function, so surface treatment technology must be used. At present, all domestic manufacturers use electrochromium plating technology to meet the corresponding technical requirements. As we all know, pickling treatment is required before electrochromium plating, but the trivalent chromium in the plating solution is a carcinogen. If these waste liquids are discharged arbitrarily, it will inevitably seriously pollute the environment. Due to the current strict national environmental protection requirements, some small electroplating companies have been closed, and large electroplating companies must strictly post-treat the waste liquid before discharging it, so the production cost has increased significantly. At the same time, the anti-corrosion performance of electroplated chromium depends on the thickness of the electroplating layer. In order to reduce costs, many companies control the thickness of the electroplating layer at the lower limit, resulting in many cases. The anti-corrosion performance cannot meet the requirements of the salt spray test standard.

[0003] Therefore, how to provide a novel method for preparing a pressing wheel for large-scale automated woodworking machinery is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0004] In view of this, the present invention provides a novel preparation method for a pressing wheel for large-scale automated woodworking machinery. The production process does not emit three wastes, is green and environmentally friendly, easy to operate, and has low cost. The surface hardness, wear resistance, and corrosion resistance of the pressing wheel achieved in the preparation are far higher than the technical index requirements.

[0005] To achieve the above object, the present invention provides a novel method for preparing a pressing wheel for large-scale automated woodworking machinery, comprising the following steps: Step (1), rough processing of materials: using 45 steel round bar material, the material is subjected to preliminary machining after cutting to obtain a primary workpiece; Step (2), pre-heat treatment: the primary workpiece obtained in step (1) is placed in an atmosphere protection heat treatment furnace for pre-heat treatment, the primary workpiece is placed on a tooling rack, pushed into the heat treatment furnace for the first heating, and after being taken out of the furnace, it is placed in 20° C. clean water for cooling, and then the primary workpiece is put into the heat treatment furnace again for secondary heating, and after being taken out of the furnace, it is placed in the air for cooling; Step (3), finishing process: the primary workpiece that has been pre-heat treated is finished by a high-precision machine tool. The inner hole is enlarged in advance during the finishing process so that a margin is reserved for the inner hole of the primary workpiece wheel. After processing, a secondary workpiece is obtained, wherein the relationship between the thickness and the increase in diameter is as follows: ΔΦ=0.0912×H Where: ΔΦ-increment of the inner hole of the pressing wheel diameter Φ, micrometer; H-thickness of the compound layer after multi-component co-penetration, micrometer; Step (4), gas co-penetration treatment: the secondary workpiece after fine processing in step (3) is directly placed in a gas co-penetration furnace, and the pressure in the co-penetration furnace is always maintained at a positive pressure of 200 to 1200 Pa. After the treatment, a pressing wheel is obtained, and then the pressing wheel is directly taken out of the furnace and cooled in the air; Step (5), beautification treatment: the pressing wheel treated in step (4) is placed in a sealed furnace, and nitrogen, ammonia and a beautifying agent are introduced to heat the pressing wheel. After the treatment, the pressing wheel is placed in the air to cool.

[0006] Preferably, the first heating in step (2) is performed at a temperature of 840-860° C. for 1 hour.

[0007] Preferably, the secondary heating in step (2) is performed at a temperature of 580-620° C. for 1.5 hours.

[0008] Preferably, in step (4), the temperature of the gas co-penetration furnace is 580-680° C., and the co-penetration time is 1.0-2.5 hours.

[0009] Preferably, the atmosphere in the co-infiltration furnace in step (4) is a mixed gas of ammonia, natural gas, carbon dioxide, nitrogen and an additive, and the additive is a mixture of methanol, acetone, formamide and alcohol.

[0010] Preferably, the beautifying agent used in step (5) is a mixture of alcohol and acetone.

[0011] Preferably, in step (5), the heating temperature is 400-600° C. and the heating time is 1.5 hours.

[0012] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects: 1. The present invention abandons the polluting electroplating technology, and can directly carry out multi-element co-infiltration without any acid washing, alkali washing and other treatments in the early stage. There is no discharge of any three wastes in the whole production process, thus realizing green production; 2. The present invention can be used in specific production furnaces that have been developed (such as Figure 4 ) is produced, which is easy to operate and low in cost; 3. The finished pressing wheel prepared by the present invention passes the 120-hour neutral salt spray corrosion test, and the protection level is above level 8, which is much higher than the technical index of the 48-hour neutral salt spray test and protection level 8 required for the pressing wheel.

[0013] 4. The surface hardness of the finished pressing wheel prepared by the present invention is similar to that of chrome plating, and the thickness is higher than that of the chrome plating layer. The most important thing is that the surface friction coefficient is only 0.2-0.3 (the friction coefficient of steel is 0.6-0.7, and the friction coefficient of the chrome plating layer is about 0.5), so the wear resistance is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0015] Figure 1 The present invention is a flowchart of a novel method for preparing a pressing wheel for large-scale automated woodworking machinery.

[0016] Figure 2 The figure is a schematic diagram of the metallographic structure of a pressing wheel manufactured by the novel preparation method of a pressing wheel for large-scale automated woodworking machinery of the present invention.

[0017] Figure 3 The present invention is a schematic diagram of a pressing wheel manufactured by a novel preparation method of a pressing wheel for large-scale automated woodworking machinery.

[0018] Figure 4 It is a schematic diagram of the structure of a specific production furnace of the present invention.

[0019] Figure 5 It is a structural schematic diagram of the special tooling rack of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Please refer to the attached Figure 1-5 , which is a new preparation method for a pressing wheel for large-scale automated woodworking machinery disclosed in the present invention.

[0022] The novel preparation method of the pressing wheel for large-scale automated woodworking machinery provided by the present invention comprises the following steps: Step (1), rough processing of materials: using 45 steel round bar materials, the materials are preliminarily machined after cutting to obtain primary workpieces, which preliminarily meet the size requirements; Step (2), pre-heat treatment: the primary workpiece obtained in step (1) is placed in an atmosphere protection heat treatment furnace for pre-heat treatment, the primary workpiece is placed on a tooling rack, pushed into the heat treatment furnace for the first heating, and after being taken out of the furnace, it is placed in 20° C. clean water for cooling, and then the primary workpiece is put into the heat treatment furnace again for secondary heating, and after being taken out of the furnace, it is placed in the air for cooling; Step (3), finishing process: the primary workpiece that has been pre-heat treated is finished by a high-precision machine tool. The inner hole is enlarged in advance during the finishing process so that a margin is reserved for the inner hole of the primary workpiece. After the processing, a secondary workpiece is obtained. The relationship between the thickness and the increase in diameter is as follows: ΔΦ=0.0912×H Where: ΔΦ-increment of the inner hole of the pressing wheel diameter Φ, micrometer; H-thickness of the compound layer after multi-component co-penetration, micrometer; It should be noted that, in order to meet the requirements of surface hardness and corrosion resistance of the pressing wheel, a multi-element co-penetration treatment is required in the later stage, and the inner hole of the pressing wheel will be deformed. The inner hole of the finished product requires a relatively strict tolerance, so a margin must be reserved. After a large number of experiments, the present invention found that after the multi-element co-penetration treatment, the inner hole will shrink, so the inner hole must be enlarged in advance for fine processing, and the above-mentioned formula for the relationship between thickness and diameter increase is also obtained through a large number of experiments combined with theory.

[0023] Step (4), gas co-penetration treatment: the secondary workpiece after fine processing in step (3) is directly placed in a gas co-penetration furnace, and the pressure in the co-penetration furnace is always maintained at a positive pressure of 200 to 1200 Pa. After the treatment, a pressing wheel is obtained, and then the pressing wheel is directly taken out of the furnace and cooled in the air. The pressing wheel obtained in this step has a surface hardness, wear resistance and corrosion resistance that meet the requirements, but the surface color is not neat and beautiful enough.

[0024] Step (5), beautification treatment: the pressing wheel treated in step (4) is placed in a sealed furnace, and nitrogen, ammonia and a beautifying agent are introduced to heat the pressing wheel. After the treatment, the pressing wheel is placed in the air to cool.

[0025] In order to further optimize the above technical solution, the temperature of the first heating in step (2) is 840-860° C. and the time is 1 hour.

[0026] In order to further optimize the above technical solution, the heating temperature of the secondary heating in step (2) is 580-620° C. and the time is 1.5 hours.

[0027] In order to further optimize the above technical solution, the temperature of the gas co-penetration furnace in step (4) is 580-680° C., and the co-penetration time is 1.0-2.5 hours.

[0028] In order to further optimize the above technical solution, the atmosphere in the co-infiltration furnace in step (4) is a mixed gas of ammonia, natural gas, carbon dioxide, nitrogen and additives, and the additives are a mixture of methanol, acetone, formamide and alcohol.

[0029] In order to further optimize the above technical solution, the beautifying agent used in step (5) is a mixture of alcohol and acetone.

[0030] In order to further optimize the above technical solution, the heating temperature in step (5) is 400-600° C. and the heating time is 1.5 hours.

[0031] The pressing wheel produced by the above method has a 30-50 micron compound layer containing multiple elements on the surface, followed by a transition layer with a thickness of 0.2-0.4 mm. The hardness of the compound layer is HV500-650, and the hardness of the transition layer is HV450-350, which is much higher than that of the base material. At the same time, the compound layer is an intermetallic compound with good corrosion resistance, thus ensuring wear resistance and corrosion resistance. The outermost layer is a beautification layer with a thickness of 3-5 microns to ensure the surface cleanness and aesthetics of the pressing wheel.

[0032] Embodiment 1: The novel preparation method of the pressing wheel of this embodiment includes the following processing steps: (1) Materials and rough processing: 45 steel round bars are used. After cutting, the materials are preliminarily machined to obtain rough pressing wheels. The dimensions of each part are 0.5-1.0mm larger than the requirements of the drawings. The number of pieces processed is 50. (2) Pre-heat treatment: The 50 pressing wheels obtained in step (1) are placed in an atmosphere protection heat treatment furnace for pre-heat treatment. The pressing wheels are placed on a special tooling rack (such as Figure 5 ), push it into a heat treatment furnace for heating at 840°C for 1 hour, and cool it in 20°C water after it comes out of the furnace; then put the workpiece into the heat treatment furnace again for secondary heating at 580°C for 1.5 hours, and cool it in air after it comes out of the furnace; (3) Finishing process: The pressing wheel that has been pre-heat treated in step (2) is processed using a high-precision machine tool, and the inner hole diameter is processed to Φ17+0.029-Φ17+0.008, and the remaining parts are processed to the dimensions required by the drawing; (4) Gas co-penetration treatment: The pressing wheel after fine processing in step (3) is directly placed in a gas co-penetration furnace at 580°C, and various gases are introduced as shown in Table 1: Table 1 Example 1 Multi-component co-permeation gas amount

[0033] The co-penetration is performed for 2.5 hours, and the pressure in the co-penetration furnace is always maintained at a positive pressure of 500-600Pa. After the treatment, the pressing wheel is directly taken out of the furnace and cooled in the air; (5) Beautification treatment: The pressing wheel treated in step (4) is placed in a specific production furnace that has been developed (such as Figure 4 ), nitrogen, ammonia and beautifying agent were introduced, the heating temperature was 450°C, the time was 1.5 hours, and the various gases introduced were shown in Table 2: Table 2 Example 1 Beautification treatment gas volume

[0034] The compound layer thickness in the surface penetration layer of the pressing wheel prepared in this embodiment is 40 microns, the total penetration layer thickness is 0.15 mm, and the beautification layer thickness is 2-3 microns; after a 96-hour salt spray test, the protection level is 8.

[0035] The cost accounting of this embodiment 1 is: 2.5 yuan / piece, and the cost of traditional technology is: 4.0 yuan / piece.

[0036] Embodiment 2: The difference between Example 2 and Example 1 is that in Example 2, the number of pressing wheels for multi-component co-infiltration is greatly increased, which requires changes to the multi-component co-infiltration and beautification treatment process, as follows.

[0037] The novel preparation method of the pressing wheel in this embodiment includes the following processing steps: (1) Materials and rough processing: 45 steel round bars are used as materials. After cutting, the materials are preliminarily machined to obtain rough pressing wheels. The dimensions of each part are 0.5-1.0mm larger than the requirements of the drawings. The number of pieces processed is 200; special tooling racks are made. (2) Pre-heat treatment: The 200 pressing wheels obtained in step (1) are placed in an atmosphere protection heat treatment furnace for pre-heat treatment. The pressing wheels are placed on a special tooling rack (such as Figure 5 ), and then pushed into a heat treatment furnace for heating at a temperature of 850°C for 2.0 hours, and then cooled in 20°C water after being taken out of the furnace; then the workpiece is put into the heat treatment furnace again for secondary heating at a temperature of 600°C for 2.5 hours, and then cooled in the air after being taken out of the furnace; (3) Finishing process: The pressing wheel that has been pre-heat treated in step (2) is processed using a high-precision machine tool, and the inner hole diameter is processed to Φ17+0.028-Φ17+0.07. The remaining parts are processed to the dimensions required by the drawing.

[0038] (4) Gas co-penetration treatment: The pressing wheel after fine processing in step (3) is directly placed in a 600°C gas co-penetration furnace, and various gases are introduced as shown in Table 3: Table 3 Example 2 Multi-component co-permeation gas amount

[0039] The co-infiltration is carried out for 2.5 hours, and the pressure in the co-infiltration furnace is always maintained at a positive pressure of 800-600Pa. After the treatment, the pressing wheel is directly taken out of the furnace and cooled in the air.

[0040] (5) Beautification treatment: The pressing wheel treated in step (4) is placed in a specific production furnace that has been developed (such as Figure 4 ), nitrogen, ammonia and beautifying agent are introduced into the furnace, the heating temperature is 500°C, the time is 2.0 hours, and the various gases introduced are shown in Table 4: Table 4 Example 2 Beautification treatment gas volume

[0041] The thickness of the compound layer in the surface penetration layer of the pressing wheel prepared in this embodiment is 35 microns, the total penetration layer thickness is 0.12 mm, and the beautification layer is 2-3 microns; after a 96-hour salt spray test, the protection level is 8.

[0042] Compared with the traditional method, the method for preparing the pressing wheel of the present invention has the following advantages: 1) The multi-element co-penetration technology is adopted and the electroplating chromium technology is abandoned. No acid washing, alkali washing and other operations are required in the early stage, and the whole production process is green and environmentally friendly.

[0043] 2) Explore the relationship between the deformation of the pressing wheel and the finishing reserve in the multi-element co-infiltration process, which can be expressed by the following formula: ΔΦ=0.0912×H Wherein, ΔΦ is the increment of the inner hole diameter Φ of the pressing wheel, in microns; H is the thickness of the compound layer after multi-element co-penetration, in microns.

[0044] 3) Develop beautification processing technology to ensure the neatness and beauty of product appearance and improve the qualification rate.

[0045] 4) The cost is about 35% lower than the traditional process, and the performance is much higher than the traditional technology.

[0046] Therefore, compared with the traditional method, the present invention simplifies the processing process. Since the size of chromium electroplating cannot be accurately controlled, grinding must be performed after plating to ensure the size. The present invention explores the relationship between the deformation amount and the compound layer, and eliminates the subsequent grinding process through the pre-reservation method.

[0047] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A novel method for preparing a pressing wheel for large-scale automated woodworking machinery, characterized in that: The following steps are involved: Step (1), rough processing of materials: using 45 steel round bar material, after cutting, the material is subjected to preliminary mechanical processing to obtain a primary workpiece; Step (2), pre-heat treatment: the primary workpiece obtained in step (1) is placed in an atmosphere protection heat treatment furnace for pre-heat treatment, the primary workpiece is placed on a tooling rack, pushed into the heat treatment furnace for the first heating, and after being taken out of the furnace, it is placed in 20° C. clean water for cooling, and then the primary workpiece is put into the heat treatment furnace again for secondary heating, and after being taken out of the furnace, it is placed in the air for cooling; Step (3), finishing process: the primary workpiece that has been pre-heat treated is finished by a high-precision machine tool. The inner hole is enlarged in advance during the finishing process so that a margin is reserved for the inner hole of the primary workpiece wheel. After processing, a secondary workpiece is obtained, wherein the relationship between the thickness and the increase in diameter is as follows: ΔΦ=0.0912×H Where: ΔΦ-increment of the inner hole of the pressing wheel diameter Φ, micrometer; H-thickness of the compound layer after multi-component co-penetration, micrometer; Step (4), gas co-penetration treatment: the secondary workpiece after fine processing in step (3) is directly placed in a gas co-penetration furnace, and the gas co-penetration furnace is always maintained at a positive pressure of 200 to 1200 Pa. After the treatment, a pressing wheel is obtained, and then the pressing wheel is directly taken out of the furnace and cooled in the air; Step (5), beautification treatment: the pressing wheel treated in step (4) is placed in a sealed furnace, and nitrogen, ammonia and a beautification agent are introduced to heat the pressing wheel. After the beautification treatment, the pressing wheel is placed in the air to cool.

2. The novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to claim 1 is characterized in that: The temperature of the first heating in step (2) is 840-860° C. and the time is 1 hour.

3. The novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to claim 1 is characterized in that: The secondary heating in step (2) is performed at a temperature of 580-620° C. for 1.5 hours.

4. The novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to claim 1 is characterized in that: In the step (4), the temperature of the gas co-penetration furnace is 580-680° C., and the co-penetration time is 1.0-2.5 hours.

5. The novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to claim 1, characterized in that: The atmosphere in the gas co-penetration furnace in step (4) is a mixed gas of ammonia, natural gas, carbon dioxide, nitrogen and additives, and the additives are a mixture of methanol, acetone, formamide and alcohol.

6. The novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to claim 1, characterized in that: The beautifying agent used in step (5) is a mixture of alcohol and acetone.

7. The novel preparation method of the pressing wheel for large-scale automated woodworking machinery according to claim 1, characterized in that: In the step (5), the heating temperature is 400-600° C. and the heating time is 1.5 hours.

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