Surface-reinforced wear-resistant composite plate and preparation device and method thereof

Abstract

The present application belongs to the technical field of wear-resistant materials, and particularly relates to a surface-strengthened wear-resistant composite plate and a preparation device and method thereof. In order to solve the problem that the hardness and wear resistance of a conventional surfacing wear-resistant composite plate have reached the upper limit under current process conditions, and to enable the performance of the composite plate to still meet the requirements under some extreme working conditions, the present application introduces the concept of surface strengthening into the manufacture of the wear-resistant composite plate, selects millimeter-level ceramic particles, and adds the ceramic particles when the surfacing layer surface is in a semi-solid state, thereby improving the interfacial bonding strength between the non-metallic filler and the semi-solid metal, and enabling the interfacial metallurgical bonding to have a high quality. In addition, after the millimeter-level ceramic particles are added, a water mist spraying cooling method is used to avoid the generation of penetrating cracks caused by direct quenching, and to also compensate for the problem of insufficient hardness caused by slow cooling. The present application organically combines the wear resistance of the ceramic particles and the mechanical properties of the metal, so that the entire composite plate has sufficient wear resistance under extreme working conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of wear-resistant materials, and in particular relates to a surface-reinforced wear-resistant composite plate and a preparation device and method thereof. Background Art

[0002] With the rapid development of industrial technology, the wear problem of mechanical equipment in various harsh environments has become increasingly prominent, seriously affecting the service life and production efficiency of the equipment. In the actual service process, mining machinery is not only in harsh working conditions such as high-temperature oxidation, corrosion, and high impact, but also subject to wear from hard abrasives, causing parts to fail quickly due to wear. Severe wear causes a large amount of metal loss. At the same time, the rapid failure of parts due to wear requires a lot of manpower and material resources for frequent replacement, resulting in production stoppages and increased costs, which has a great adverse impact on the production efficiency and economic benefits of the enterprise. For this reason, the development of a new type of wear-resistant material that has both excellent wear resistance and good processability and cost-effectiveness has become an urgent need in the current industrial field.

[0003] Hardfacing wear-resistant composite plates are a type of wear-resistant material widely used in modern industrial production. They are formed by welding one or more layers of wear-resistant alloy onto the surface of ordinary steel plates, creating a composite material with high hardness and wear resistance. This material not only retains the strength and toughness of ordinary steel plates but also significantly improves the surface wear resistance, enabling it to maintain excellent wear resistance for extended periods in harsh operating environments, thereby extending the service life of equipment. Its main application areas include mining, metallurgy, cement production, thermal power generation, and other applications with high wear resistance requirements. Hardfacing wear-resistant composite plates offer excellent wear resistance. Their surface wear-resistant layer is typically composed of a high-hardness alloy material, reaching hardnesses exceeding 60HRC and even as high as 70HRC. Furthermore, this material exhibits excellent machinability, such as weldability, cuttability, and formability, enabling companies to process and manufacture various complex shapes according to specific needs, greatly expanding its scope of application and flexibility.

[0004] Currently, hardfacing wear-resistant technology is used in the processing of many important metal materials and key components of mining machinery to extend equipment life, reduce the frequency of maintenance and replacement, thereby reducing costs and improving production efficiency. Currently, high-chromium cast iron hardfacing wear-resistant composite plates are the most representative. This material offers excellent wear and heat resistance, making it suitable for a wide range of industrial applications, particularly in conditions requiring high-temperature and wear resistance. However, the hardness and wear resistance of metal materials have reached their upper limits under current process conditions. In some extreme operating conditions, such as extremely high temperatures or severe corrosive environments, their performance is difficult to meet requirements. Summary of the Invention

[0005] In order to solve the problem that the hardness and wear resistance of the conventional surfacing wear-resistant composite plate has reached the upper limit under the current process conditions, and to make its performance still meet the requirements of key parts of mine machinery under some extreme working conditions, the application provides a surface strengthening type wear-resistant composite plate and a preparation device and method thereof.

[0006] The Al2O3 particles are ceramic particles with high hardness, and the Vickers hardness is much higher than that of metal materials. Therefore, the iron-based ceramic composite material prepared by adding Al2O3 particles into cast iron is expected to greatly improve the hardness of the wear-resistant composite plate, and points out an effective way to solve this problem. However, adding ceramic particles directly into the flux-cored wire used in the surfacing process will reduce the bonding quality of the substrate and the surfacing layer, which will adversely affect the wear resistance of the wear-resistant composite plate. In addition, excessive use of ceramic particles will also increase the cost of the wear-resistant composite plate.

[0007] Therefore, surface strengthening is a new idea to solve this problem. The flux-cored wire melts first and then solidifies on the substrate to form a surfacing layer during welding. When the surface layer of the surfacing layer is liquid, the added ceramic particles are easy to gather; when the surface layer of the surfacing layer is solid, the ceramic particles cannot be directly added. Therefore, adding ceramic particles when the surface layer of the surfacing layer is semi-solid becomes a new solution. In the service process of the wear-resistant composite plate, the surface strengthened wear-resistant composite plate can directly bear the load, and the existence of the intermediate metal transition layer can reduce the stress and provide good toughness support.

[0008] In order to achieve the above purpose, the application adopts the following technical scheme:

[0009] In the first aspect, the application provides a preparation device for a surface strengthening type wear-resistant composite plate, which comprises a workbench, a carbon steel substrate is arranged on the workbench, a ceramic particle spray head is arranged above the carbon steel substrate for spraying millimeter-sized ceramic particles, an infrared temperature measuring gun is arranged on one side of the ceramic particle spray head, a preheating flame spray head, a welding gun and a water mist spray head are also arranged above the carbon steel substrate, and the preheating flame spray head, the welding gun and the water mist spray head are fixed on a support, and the preheating flame spray head is connected with an acetylene input pipe and an oxygen input pipe.

[0010] In the second aspect, the application also provides a preparation method for a surface strengthening type wear-resistant composite plate, based on the above-mentioned preparation device for a surface strengthening type wear-resistant composite plate, comprising the following steps:

[0011] Step 1, clean the welding area of the carbon steel substrate, and use the preheating flame spray head to preheat the welding area of the carbon steel substrate. The welding area is cleaned to remove oil stains, rust, moisture, etc., so as to ensure the welding quality;

[0012] Step 2: Use a welding gun to weld the flux-cored wire into the welding area of ​​the carbon steel substrate. The welding process adopts the cladding alloy process. While welding, use an infrared temperature measuring gun to measure the temperature of the surface of the cladding layer in real time. When the temperature of the surface of the cladding layer reaches a semi-solid state, use a ceramic particle nozzle to evenly spray millimeter-sized ceramic particles onto the surface of the cladding layer.

[0013] Step 3: After spraying the millimeter-sized ceramic particles, use a water mist nozzle to spray water mist onto the cladding layer;

[0014] Step 4: After welding, the obtained composite plate is cut, polished and cleaned to obtain the surface-reinforced wear-resistant composite plate.

[0015] Furthermore, the preheating temperature in step 1 is 300-350° C., and the preheating time is 10-15 min.

[0016] Furthermore, the parameters of the surfacing alloy process in step 2 are: welding voltage 25~28V, welding current 170~220A, welding speed 120mm·min -1 .

[0017] Furthermore, the elemental composition of the flux-cored welding wire in step 2 is as follows:

[0018] Cr: 18.6~26.8wt.%, B: 0.1~0.6wt.%, C: 5.0~5.5wt.%, Si: 2.0~2.6wt.%; Mn: 0.1~0.6wt.%.

[0019] Furthermore, in step 2, the temperature at which the surface of the surfacing layer is semi-solid is between 1000° C. and 1200° C., which can ensure that the millimeter-sized ceramic particles are added when the surface of the surfacing layer is in a semi-solid state.

[0020] Furthermore, the distance between the water mist nozzle and the welding gun is 5 to 15 cm.

[0021] Furthermore, in step 2, the millimeter-sized ceramic particles are selected as Al2O3 particles with a particle size of 1 mm. The Al2O3 particles need to be cleaned and dried before spraying. The cleaning is carried out by ultrasonic vibration cleaning for 3 minutes to wash away impurities and oil stains on the surface of the Al2O3 particles, and the drying is natural drying.

[0022] In a third aspect, the present invention further provides a surface-reinforced wear-resistant composite plate prepared by the above-mentioned method for preparing a surface-reinforced wear-resistant composite plate.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. Based on the high hardness and high wear resistance of millimeter-sized ceramic particles, the millimeter-sized ceramic particle reinforced iron-based wear-resistant material has better hardness and wear resistance than high-chromium cast iron. The ceramic particles directly rub against the working part on the surface of the surfacing layer, which greatly increases the wear resistance of the wear-resistant composite plate.

[0025] 2. The millimeter-sized ceramic particles of the present invention are added when the surface of the surfacing layer is semi-solid. Semi-solid metal forming processing is the optimal method for adding ceramic particles. This method is easy to add non-metallic fillers, and as long as the appropriate addition temperature is selected, it is beneficial to improve the interface bonding strength between the non-metallic filler and the semi-solid metal, and has a high interface metallurgical bonding quality.

[0026] 3. This invention abandons the traditional preheating and slow cooling approach to control weld deformation and cracking, and instead proposes a preheating and rapid cooling approach. This approach offers the following key advantages: 1) The use of water mist cooling reduces the tendency to cold cracking, preventing the extensive cracking associated with direct quenching. This allows for more time for the weld overlay to form, while also compensating for the lack of hardness associated with air cooling. 2) Preheating controls weld deformation and cracking, while rapid cooling with water mist spraying adjusts the growth direction of hard carbides, significantly improving the wear resistance of the composite plate.

[0027] 4. The key technology for preparing the surface-reinforced wear-resistant composite plate proposed in the present invention is to evenly add millimeter-sized ceramic particles when the surface of the weld overlay layer is semi-solid, so that the millimeter-sized ceramic particles and the metal matrix are evenly distributed and metallurgically bonded with high quality. The wear resistance of the ceramic particles and the mechanical properties of the casting alloy can be organically combined, so that the entire composite plate has sufficient wear resistance during operation, thereby extending the service life of mechanical parts and ultimately improving the practical effects and economic benefits of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of a device for preparing a surface-reinforced wear-resistant composite plate according to the present invention.

[0029] Figure 2 This is a schematic cross-sectional view of the surfacing layer of the surface-reinforced wear-resistant composite plate prepared in Example 2.

[0030] Figure 3 This is a metallographic diagram of the cross section of the surfacing layer of the surface-reinforced wear-resistant composite plate prepared in Example 2.

[0031] Figure 4 This is a metallographic image of the surface of the surfacing layer of the surface-reinforced wear-resistant composite plate prepared in Example 2.

[0032] Figure 5 This is the internal organization diagram of the surface layer of the cladding layer of Example 2.

[0033] Figure 6 This is the internal organization diagram of the surface layer of the cladding layer of Example 3.

[0034] Figure 7 This is the internal organization diagram of the surface layer of the weld overlay layer of Example 4.

[0035] Figure 8 This is a bar chart showing the friction and wear results of the surface-reinforced wear-resistant composite plates prepared in Example 2, Example 3, Example 4 and Comparative Example 1.

[0036] Figure 9 This is a histogram of the cross-sectional hardness of the surfacing layer of the surface-reinforced wear-resistant composite plates prepared in Example 2, Example 3, Example 4 and Comparative Example 1.

[0037] Figure 10 This is a histogram of the surface hardness of the surfacing layer of the surface-reinforced wear-resistant composite plates prepared in Example 2, Example 3, Example 4 and Comparative Example 1.

[0038] Among them, 1-ceramic particle nozzle, 2-infrared temperature measuring gun, 3-carbon steel base plate, 4-workbench, 5-preheating flame nozzle, 6-welding gun, 7-water mist nozzle, 8-acetylene inlet pipe, 9-oxygen inlet pipe, 10-millimeter-grade ceramic particles, 11-surface layer of surfacing layer, 12-middle layer of surfacing layer, 13-joining surface of surfacing layer. DETAILED DESCRIPTION

[0039] In order to further illustrate the technical solution of the present invention, the present invention is further described below through examples. Example 1

[0040] like Figure 1 As shown, a preparation device for a surface-reinforced wear-resistant composite plate in this embodiment includes a workbench 4, a carbon steel substrate 3 is arranged on the workbench 4, a ceramic particle nozzle 1 is arranged above the carbon steel substrate 3, for spraying millimeter-level ceramic particles 10, an infrared temperature measuring gun 2 is arranged on one side of the ceramic particle nozzle 1, and a preheating flame nozzle 5, a welding gun 6 and a water mist nozzle 7 are also arranged above the carbon steel substrate 3, and the preheating flame nozzle 5, welding gun 6 and water mist nozzle 7 are fixed on a bracket, and an acetylene input pipe 8 and an oxygen input pipe 9 are connected to the preheating flame nozzle 5. Example 2

[0041] The method for preparing a surface-reinforced wear-resistant composite plate of this embodiment is based on the device for preparing a surface-reinforced wear-resistant composite plate described in the first embodiment, and includes the following steps:

[0042] Step 1: Clean the welding area of ​​the carbon steel substrate 3 and preheat the welding area of ​​the carbon steel substrate 3 using a preheating flame nozzle 5. The preheating temperature is 300° C. and the time is 12 minutes. The carbon steel substrate 3 is a Q235 substrate.

[0043] Step 2: Use a welding gun 6 to weld the flux-cored wire in the welding area of ​​the carbon steel substrate 3. The welding process adopts a surfacing alloy process. While welding, use an infrared temperature measuring gun 2 to measure the temperature of the surface layer 11 of the surfacing layer in real time. When the temperature of the surface layer 11 of the surfacing layer reaches a semi-solid state, use a ceramic particle nozzle 1 to evenly spray millimeter-sized ceramic particles 10 onto the surface layer 11 of the surfacing layer. The temperature of the surface layer 11 of the surfacing layer is 1000°C. The millimeter-sized ceramic particles 10 are Al2O3 particles with a particle size of 1 mm. The parameters of the surfacing alloy process are: welding voltage 25V, welding current 200A, and welding speed 120mm·min -1 , the element composition of the flux-cored welding wire is as follows: Cr: 18.6wt.%, B: 0.4wt.%, C: 5.0wt.%, Si: 2.0wt.%; Mn: 0.1wt.%;

[0044] Step 3: After spraying the millimeter-sized ceramic particles 10, use the water mist nozzle 7 to spray water mist onto the surfacing layer. The distance between the water mist nozzle 7 and the welding gun 6 is 5 cm.

[0045] Step 4: After welding, the obtained composite plate is cut, polished and cleaned to obtain the surface-enhanced wear-resistant composite plate. A wear-resistant specimen with a size of 75 mm × 25 mm × 10 mm and a cubic block with a size of 10 mm × 10 mm × 10 mm are cut from the surface-enhanced wear-resistant composite plate using a DK7763F electric spark CNC wire cutting machine; the surface of the specimen is wiped with anhydrous ethanol to ensure that the surface of the specimen is clean, free of oil stains and rust;

[0046] Step 5: First, use 400# sandpaper to coarsely grind the prepared cube with a size of 10mm×10mm×10mm to remove surface stains, oxide layer, etc., and then use 800#, 1200#, 1500#, and 2000# sandpaper to finely grind until the surface is smooth and scratch-free, mirror-like or nearly mirror-like. Then, use a high-efficiency diamond metallographic polishing agent with a particle size of 2.5μm to polish until the surface of the cube becomes a reflective and shiny mirror. Then, use a stainless steel corrosive agent to corrode for 70s, wipe with alcohol, and blow dry with a hair dryer, and then observe the metallographic structure through the HFX-IIA Nikon metallographic microscope;

[0047] Step 6, the prepared wear-resistant sample with the size of 75mmx25mmx10mm is detected by HR-150A Rockwell hardness tester for macro hardness, 10 test points are taken at different positions as needed, the test load is 1470N, the load lasts for 15s, the maximum and minimum values are removed, and the average value is calculated, the hardness of the surface layer 11 of the surfacing layer of this embodiment is 57.8HRC, the hardness of the middle layer 12 of the surfacing layer is 56.9HRC, and the hardness of the joint surface 13 of the surfacing layer is 56.3HRC Figure 9 The hardness of the surface of the surfacing layer is 60.1HRC Figure 10 .

[0048] Figure 2 The surfacing layer cross section diagram of the surface strengthening type wear-resistant composite plate prepared in this embodiment is shown, which includes millimeter level ceramic particles 10, and from top to bottom, the surfacing layer surface 11, the surfacing layer middle layer 12 and the surfacing layer joint surface 13, and the surfacing layer surface is not marked.

[0049] Step 7, the LGM-130 dry sand rubber wheel abrasion tester produced by Jinan Liangong Test Technology Co., Ltd. is used for detection, and the test parameters are as follows: the diameter of the rubber wheel is 229mm, the hardness is 60HA, the weight of the weight is 2.5kg, the rotating speed of the rubber wheel is 192rad·min -1 Before testing, the weight of the polished and cleaned wear-resistant sample is the initial weight M0, then the wear-resistant sample is ground for 1h, cleaned, wiped with alcohol and dried, the weight of the wear-resistant sample is M1, the absolute weight loss of the wear-resistant sample is calculated as ΔM=M0-M1, and the average value of three wear-resistant samples is taken, the wear loss of this embodiment is 198mg Figure 8 . Example Three

[0050] The preparation method of a surface strengthening type wear-resistant composite plate in this embodiment is based on the preparation device of a surface strengthening type wear-resistant composite plate described in embodiment one, and includes the following steps:

[0051] Step 1, the welding area of the carbon steel base plate 3 is cleaned, and the welding area of the carbon steel base plate 3 is preheated by using the preheating flame jet 5, the preheating temperature is 350℃, and the time is 15min, and the carbon steel base plate 3 uses Q235 base plate;

[0052] Step 2, using the welding torch 6 to weld the flux-cored wire in the welding area of the carbon steel base plate 3, the welding process adopts the surfacing alloy process, while welding, using the infrared temperature gun 2 to measure the temperature of the surfacing layer surface layer 11 in real time, when the surfacing layer surface layer 11 reaches the semi-solid temperature of 1100℃, the ceramic particle nozzle 1 is used to uniformly spray the millimeter-level ceramic particles 10 to the surfacing layer surface layer 11, the surfacing alloy process parameters are: welding voltage 28V, welding current 220A, welding speed 120mm·min -1 The element composition of the flux-cored wire is as follows: Cr: 26.5wt.%, B: 0.1wt.%, C: 5.2wt.%, Si: 2.1wt.%, Mn: 0.2wt.%;

[0053] Step 3, after the spraying of the millimeter-level ceramic particles 10 is completed, the water mist nozzle 7 is used to spray water mist onto the surfacing layer, the distance between the water mist nozzle 7 and the welding torch 6 is 10cm;

[0054] Step 4, after the welding is completed, the obtained composite plate is cut, polished and cleaned to obtain the surface strengthening type wear-resistant composite plate, a DK7763F electric spark numerical control wire cutting machine tool is used to cut a wear-resistant sample with a size of 75mm×25mm×10mm and a cubic block with a size of 10mm×10mm×10mm from the surface strengthening type wear-resistant composite plate; anhydrous ethanol is used to wipe the surface of the sample to ensure that the surface of the sample is clean, free of oil stains and free of rust;

[0055] Step 5, the prepared cubic block with a size of 10mm×10mm×10mm is first coarsely ground using 400# sandpaper to remove surface stains, oxide layers and the like, and then successively finely ground using 800#, 1200#, 1500# and 2000# sandpaper to polish the surface to be smooth and free of scratches to a mirror surface or an approximate mirror surface. Then, high-efficiency diamond metallographic polishing agent with a particle size of 2.5μm is used for polishing until the surface of the cubic block becomes a mirror surface that is reflective and bright. Then, the cubic block is corroded using stainless steel corrosion agent for 70s, wiped with alcohol and dried using a hair dryer, and then observed for metallographic structure through an HFX-IIA Nikon metallographic microscope;

[0056] Step 6, the prepared wear-resistant sample with a size of 75mm×25mm×10mm is detected for macrohardness using an HR-150A Rockwell hardness tester, 10 test points are taken at different positions as needed to test the hardness, the test load is 1470N, the load lasts for 15s, the maximum and minimum values are removed, and then the average value is calculated to obtain the hardness of the surfacing layer surface layer 11 of this embodiment as 62.0HRC, the hardness of the surfacing layer intermediate layer 12 as 60.4HRC, and the hardness of the surfacing layer joint surface 13 as 59.4HRC Figure 9); the hardness of the surfacing layer surface is 61.2HRC Figure 10 。

[0057] Step 7, using the LGM-130 dry sand rubber wheel abrasion tester produced by Jinan Liangong Test Technology Co., Ltd. to detect, the test parameters are: rubber wheel diameter 229mm, hardness 60HA, weight of weight 2.5kg, rubber wheel speed 192rad·min -1 . The weight of the polished and cleaned wear-resistant sample before testing is the initial weight M0, then the wear-resistant sample is ground for 1h, cleaned, wiped with alcohol and dried, the weight of the wear-resistant sample is M1, the absolute weight loss of the wear-resistant sample is calculated as ΔM=M0-M1, and the average value of three samples is taken to obtain the wear loss of this embodiment as 190mg Figure 8 )。 Example Four

[0058] The preparation method of the surface strengthening type wear-resistant composite board in this embodiment is based on the preparation device of the surface strengthening type wear-resistant composite board in Example One, and includes the following steps:

[0059] Step 1, the welding area of the carbon steel base plate 3 is cleaned, and a preheating flame spray head 5 is used to preheat the welding area of the carbon steel base plate 3, the preheating temperature is 330℃, and the time is 10min, and the carbon steel base plate 3 uses a Q235 base plate;

[0060] Step 2, the flux-cored wire is welded in the welding area of the carbon steel base plate 3 using a welding gun 6, and the surfacing alloy process is used, and at the same time of welding, the infrared temperature gun 2 is used to measure the temperature of the surfacing layer surface layer 11 in real time, when the surfacing layer surface layer 11 reaches the semi-solid state temperature of 1200℃, the millimeter level ceramic particles 10 are uniformly sprayed to the surfacing layer surface layer 11 using the ceramic particle spray head 1, the surfacing alloy process parameters are: welding voltage 26V, welding current 170A, and welding speed 120mm·min -1 , the element composition of the flux-cored wire is as follows: Cr: 26.8wt.%, B: 0.6wt.%, C: 5.5wt.%, Si: 2.6wt.%, and Mn: 0.6wt.%;

[0061] Step 3, after spraying the ceramic particles, the water mist is sprayed to the surfacing layer using the water mist spray head 7, and the water mist spray head 7 is separated from the welding gun 6 by 15cm;

[0062] Step 4: After welding, the obtained composite plate is cut, polished and cleaned to obtain the surface-enhanced wear-resistant composite plate. A wear-resistant specimen with a size of 75 mm × 25 mm × 10 mm and a cubic block with a size of 10 mm × 10 mm × 10 mm are cut from the surface-enhanced wear-resistant composite plate using a DK7763F electric spark CNC wire cutting machine; the surface of the specimen is wiped with anhydrous ethanol to ensure that the surface of the specimen is clean, free of oil stains and rust;

[0063] Step 5: First, use 400# sandpaper to coarsely grind the prepared cube with a size of 10mm×10mm×10mm to remove surface stains, oxide layer, etc., and then use 800#, 1200#, 1500#, and 2000# sandpaper to finely grind until the surface is smooth and scratch-free, mirror-like or nearly mirror-like. Then, use a high-efficiency diamond metallographic polishing agent with a particle size of 2.5μm to polish until the surface of the cube becomes a reflective and shiny mirror. Then, use a stainless steel corrosive agent to corrode for 70s, wipe with alcohol, and blow dry with a hair dryer, and then observe the metallographic structure through the HFX-IIA Nikon metallographic microscope;

[0064] Step 6: The prepared wear-resistant specimen with a size of 75 mm × 25 mm × 10 mm was tested for macrohardness using a HR-150A Rockwell hardness tester. The hardness was tested at 10 test points at different locations as needed. The test load was 1470 N and the load was sustained for 15 seconds. The maximum and minimum values ​​were removed and the average value was calculated. The hardness of the surface layer 11 of the cladding layer in this embodiment was 61.1 HRC, the hardness of the intermediate layer 12 of the cladding layer was 60.8 HRC, and the hardness of the joint surface 13 of the cladding layer was 60.2 HRC ( Figure 9 ); The hardness of the surfacing layer is 60.7HRC ( Figure 10 ).

[0065] Step 7: Use the LGM-130 dry sand rubber wheel wear tester produced by Jinan Liangong Testing Technology Co., Ltd. to test. The test parameters are: rubber wheel diameter 229mm, hardness 60HA, weight 2.5kg, rubber wheel speed 192rad·min -1 Before the test, the weight of the wear-resistant sample after grinding and cleaning is the initial weight M0. Then the wear-resistant sample is ground for 1 hour, wiped with alcohol and blown dry. The weight of the wear-resistant sample is M1. The absolute weight loss of the sample is calculated as △M=M0-M1. The average value of the three wear-resistant samples is taken to obtain the wear loss of this embodiment of 193mg ( Figure 8 ).

[0066] Comparative Example 1

[0067] The preparation method of a wear-resistant composite plate adopted in this comparative example comprises the following steps:

[0068] Step 1: Clean the welding area of ​​the carbon steel substrate 3 and preheat the welding area of ​​the carbon steel substrate 3 using a preheating flame nozzle 5. The preheating temperature is 300° C. and the time is 10 minutes. The carbon steel substrate 3 is a Q235 substrate.

[0069] Step 2: Use the welding gun 6 to weld the flux-cored wire into the welding area of ​​the carbon steel substrate 3. The welding process adopts the cladding alloy process. The parameters of the cladding alloy process are: welding voltage 25V, welding current 170A, welding speed 120mm·min -1 , the element composition of the flux-cored welding wire is as follows: Cr: 26.5wt.%, B: 0.1wt.%, C: 5.2wt.%, Si: 2.1wt.%; Mn: 0.2wt.%;

[0070] Step 3, after welding, the welded composite plate is cooled to room temperature in air, and the obtained composite plate is cut, polished and cleaned to obtain the wear-resistant composite plate, and a wear-resistant specimen with a size of 75 mm × 25 mm × 10 mm and a cubic block of 10 mm × 10 mm × 10 mm are cut from the wear-resistant composite plate using a DK7763F electric spark CNC wire cutting machine; the surface of the specimen is wiped with anhydrous ethanol to ensure that the surface of the specimen is clean, free of oil stains and rust;

[0071] Step 4: First, use 400# sandpaper to coarsely grind the prepared cube with a size of 10mm×10mm×10mm to remove surface stains, oxide layer, etc., and then use 800#, 1200#, 1500#, and 2000# sandpaper to finely grind until the surface is smooth and scratch-free, mirror-like or near-mirror-like. Then, use a high-efficiency diamond metallographic polishing agent with a particle size of 2.5μm to polish until the surface of the cube becomes a reflective and shiny mirror. Then, use a stainless steel corrosive agent to corrode for 70s, wipe with alcohol, and blow dry with a hair dryer, and then observe the metallographic structure through the HFX-IIA Nikon metallographic microscope;

[0072] Step 5: The prepared wear-resistant specimen with a size of 75 mm × 25 mm × 10 mm was tested for macrohardness using a HR-150A Rockwell hardness tester. The hardness was tested at 10 test points at different locations as needed. The test load was 1470 N and the load was sustained for 15 seconds. The maximum and minimum values ​​were removed and the average value was calculated. The hardness of the surface layer 11 of the cladding layer in this embodiment was 56.5 HRC, the hardness of the intermediate layer 12 of the cladding layer was 54.9 HRC, and the hardness of the joint surface 13 of the cladding layer was 52.1 HRC ( Figure 9 ); The hardness of the surfacing layer is 59.5HRC ( Figure 10 ).

[0073] Step 6: Use the LGM-130 dry sand rubber wheel wear tester produced by Jinan Liangong Testing Technology Co., Ltd. to test. The test parameters are: rubber wheel diameter 229mm, hardness 60HA, weight 2.5kg, rubber wheel speed 192rad·min -1 Before the test, the weight of the wear-resistant sample after grinding and cleaning is the initial weight M0. Then the wear-resistant sample is ground for 1 hour, wiped with alcohol and blown dry. The weight of the wear-resistant sample is M1. The absolute weight loss of the sample is calculated as △M=M0-M1. The average value of the three wear-resistant samples is taken to obtain the wear loss of this embodiment of 233mg ( Figure 8 ).

[0074] The impact of welding voltage and current on the wear-resistant composite plate is primarily reflected in the width of the resulting weld bead and the depth of the weld pool. Furthermore, during actual welding, the welding voltage and current fluctuate dynamically. The hardness and wear resistance of the wear-resistant composite plate prepared in the above embodiment are primarily determined by the addition of ceramic particles, the cooling rate and method, the content of hard carbides, and the growth direction of the hard carbides.

[0075] According to the test data and metallographic diagram of the above embodiment ( Figure 3 and Figure 4 ) and internal organization diagram of the surface of the cladding layer ( Figures 5 to 7), it was found that the idea of ​​rapid cooling by water mist spraying makes the growth direction of hard carbides perpendicular to the surface of the cladding layer, which improves the hardness of the surface layer 11 of the cladding layer of the composite plate compared to the slow cooling after welding, thereby improving the wear resistance of the composite plate. In Example 2, the water mist nozzle 7 and the welding gun 6 are 5 cm apart. Due to the more intense cooling, a large number of defects such as cracks and pores appeared on the surface layer 11 of the cladding layer, resulting in a decrease in the quality of the cladding layer; because the flux-cored welding wire used in Example 2 reduces the addition of Cr and C elements, the content of hard carbides in the cladding layer is reduced. However, after the spraying of ceramic particles, water mist forced cooling is performed, thereby regulating the growth direction of the hard carbides in the cladding layer. As a result, its hardness is even slightly higher than that of the comparative example 1. This shows that the regulation of the growth direction of hard carbides has a crucial influence on the hardness of the cladding layer. In Example 4, the water mist nozzle 7 is 15 cm away from the welding gun 6. Due to the long distance, the weld overlay layer is cooled in the air for a long time before forced water mist cooling is performed. The growth direction of the hard carbide is not effectively regulated. Although the Cr and C element contents are increased, the hardness of the weld overlay layer surface and the weld overlay layer surface layer 11 is also lower than that of Example 3, which leads to a decrease in the performance of the composite plate. In Example 3, the water mist nozzle 7 is 10 cm away from the welding gun 6. Since the cooling is more moderate than that of Example 2, only a small amount of cracks appear on the weld overlay layer surface layer 11. Moreover, Example 3 ensures a higher addition of Cr and C elements, thereby ensuring the content of hard carbides. In addition, since the distance between the water mist nozzle 7 and the welding gun 6 is moderate, it not only ensures the cooling effect, but also avoids the large-scale generation of cracks. In summary, the process parameters of Example 3 are considered to be relatively excellent process parameters. In addition, due to the addition of millimeter-sized ceramic particles 10, the wear amounts of the friction and wear tests in Examples 2, 3, and 4 are all wear losses of the millimeter-sized ceramic particles 10. Therefore, the wear amounts of these groups are relatively close, but compared with Comparative Example 1 in which no millimeter-sized ceramic particles 10 are added, the wear amounts are greatly reduced.

Claims

1. A method for preparing a surface-reinforced wear-resistant composite plate, characterized in that: A preparation device for a surface-reinforced wear-resistant composite plate includes the following steps: Step 1, cleaning the welding area of ​​the carbon steel substrate (3), and preheating the welding area of ​​the carbon steel substrate (3) using a preheating flame nozzle (5); Step 2, using a welding gun (6) to weld a flux-cored wire into a welding area of ​​a carbon steel substrate (3), the welding process adopts a surfacing alloy process, while welding, using an infrared temperature measuring gun (2) to measure the temperature of the surface of the surfacing layer in real time, when the temperature of the surface of the surfacing layer reaches a semi-solid state, using a ceramic particle nozzle (1) to evenly spray millimeter-sized ceramic particles (10) onto the surface of the surfacing layer, the temperature of the surface of the surfacing layer reaching a semi-solid state is between 1000°C and 1200°C; Step 3, after spraying the millimeter-sized ceramic particles (10), use a water mist nozzle (7) to spray water mist onto the surfacing layer, and the distance between the water mist nozzle (7) and the welding gun (6) is 5 to 15 cm; Step 4: After welding, cutting, grinding and cleaning the obtained composite plate to obtain the surface-reinforced wear-resistant composite plate; The device for preparing a surface-reinforced wear-resistant composite plate comprises a workbench (4), a carbon steel substrate (3) is arranged on the workbench (4), a ceramic particle nozzle (1) is arranged above the carbon steel substrate (3) for spraying millimeter-sized ceramic particles (10), an infrared temperature measuring gun (2) is arranged on one side of the ceramic particle nozzle (1), a preheating flame nozzle (5), a welding gun (6) and a water mist nozzle (7) are also arranged above the carbon steel substrate (3), and the preheating flame nozzle (5), the welding gun (6) and the water mist nozzle (7) are fixed on a bracket, and an acetylene input pipe (8) and an oxygen input pipe (9) are connected to the preheating flame nozzle (5); The elemental composition of the flux-cored welding wire in step 2 is as follows: Cr: 18.6-26.8 wt.%, B: 0.1-0.6 wt.%, C: 5.0-5.5 wt.%, Si: 2.0-2.6 wt.%, and Mn: 0.1-0.6 wt.%.

2. The method for preparing a surface-reinforced wear-resistant composite plate according to claim 1, wherein: The preheating temperature in step 1 is 300-350° C. and the preheating time is 10-15 min.

3. The method for preparing a surface-reinforced wear-resistant composite plate according to claim 1, wherein: The parameters of the surfacing alloy process in step 2 are: welding voltage 25-28V, welding current 170-220A, welding speed 120mm·min -1 .

4. The method for preparing a surface-reinforced wear-resistant composite plate according to claim 1, wherein: In step 2, the millimeter-sized ceramic particles (10) are Al2O3 particles with a particle size of 1 mm.

5. A surface-reinforced wear-resistant composite plate prepared according to the method for preparing a surface-reinforced wear-resistant composite plate according to any one of claims 1 to 4.

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