Modeling and manufacturing method for reversible plough point with characteristics of low resistance and being strong inside and hard outside

Abstract

Provided in the present invention are a modeling and manufacturing method for a reversible plough point with the characteristics of a low resistance and being strong inside and hard outside. By means of performing parameter optimization, three-dimensional modeling and numerical simulation analysis on a curved surface of a plough point, parameters, i.e. a ploughshare edge angle λ0, a ploughshare surface angle ε, an included angle η between a soil trace and a ploughshare edge, and a soil lifting angle θ, at which the lowest working resistance is achieved, are determined, and composition optimization design and die forging-machining-carburization-quenching-tempering treatment are performed on a base material of the plough point, such that a new reversible plough point with the characteristics of a low operation resistance, high strength toughness of a core portion, and high wear resistance of a surface layer is obtained. The present invention can effectively solve the problems of wear, failure and resistance increase which easily occur due to a plough point being subjected to high-speed impact and wear from soil, sand, stones and root blocks for a long period of time during a service process, and the present invention is expected to be widely applied to the field of manufacturing of soil contact components of agricultural machinery.

Description

Modeling and manufacturing method of a reversible plow tip with low resistance and strong inner and outer hardness Technical Field

[0001] The invention relates to a modeling and manufacturing method of a reversible plow tip with low resistance and internal strength and external hardness. Background Art

[0002] Cultivating land is the most basic operation link in agricultural planting. The main plow body, as the core component of the high-speed reversible plow, is mainly composed of a plow tip, a plow shovel, a breast plate and bars. Among them, the plow tip component mainly plays the role of breaking the soil. During its service, it is prone to wear and fracture failure due to long-term high-speed impact and wear from soil, gravel and roots. In addition, since the surface parameters of the existing reversible plow's soil-entering components cannot form a good match with the running speed, the running resistance of the plow body increases, which further leads to the acceleration of the plow tip wear process and the increase of tractor energy consumption. Therefore, the design and development of a reversible plow tip with low running resistance, high strength and toughness and high wear resistance has become one of the problems that need to be solved urgently to accelerate the high-quality development of the reversible plow industry.

[0003] To address the aforementioned issues, existing reversible plows primarily employ traditional plow surface parameter optimization methods to reduce the plow's operating resistance and employ hard alloy overlay welding on localized areas of the plow tip to protect the plow tip material. Optimizing plow surface parameters generally employs empirical design methods, semi-empirical design methods (geometric line diagramming and analytical methods), and plow surface design methods based on the plowing process. While these methods can effectively conduct qualitative and quantitative analysis of the local motion of the plow surface, they ignore soil parameters and the interaction parameters between the soil and the plow body, significantly negatively impacting the analysis of the plow's operating resistance. Advanced simulation calculations are essential to ensure realistic calculation results and more effective design methods. To address the issue of insufficient plow tip material wear resistance, reversible plow production generally employs techniques such as plasma cladding, plasma welding, and argon arc cladding, overlaying high-hardness composite coatings such as Fe-based, Ni-based, and Fe-Ni-based on the plow tip. However, due to the structural design of the flip plow tip, if only the method of welding a hard alloy layer is used to enhance the wear resistance of the plow tip, it is only applicable to a small area at the tip of the plow tip. This will cause the part of the plow tip that is not welded with a hard alloy layer to still be prone to rapid wear in a high-speed service environment, making it difficult to meet the overall high wear resistance and long service life requirements of the plow tip.

[0004] On the other hand, in recent years, with the continuous acceleration of the plow body's operating speed and the rapid development of new energy tractors, it has become an inevitable trend to reduce the plow body's resistance and reduce energy consumption while maintaining the tillage quality of the high-speed reversible plow. The main plow body, as the core component of the high-speed reversible plow, includes the plow tip, plow blade, breast plate and bars. Among them, the bar component plays the role of turning the soil, and often breaks and fails due to the high-speed impact of soil and stones. Therefore, the reversible plow bars in high-speed service environments not only require good surface parameter design to obtain lower operating resistance, but also must meet high strength and toughness matching performance to resist the impact of soil and stones.

[0005] To date, the most widely used method for designing plow body surfaces is the horizontal straight line method. The principle of the horizontal straight line method for forming plow body surfaces is to use a three-dimensional coordinate system, with straight lines moving along directrixes (trajectory lines or guide lines) that remain parallel to the XOY coordinate plane, while continuously varying the angle (line angle) between the straight lines and the ZOX coordinate plane to form the surface. However, using the horizontal straight line method alone to optimize plow body surface parameters cannot effectively describe the actual soil turning process. The lack of interaction parameters between the soil and the plow body prevents quantitative analysis of the optimized plow body's working resistance. Furthermore, for boron steel widely used in high-speed reversing plow bars, reversing plow manufacturers generally use a quenching and tempering process to strengthen it, resulting in reversing plow bar components composed of a lath martensite structure of at least 98%. Therefore, simply optimizing heat treatment process parameters (such as temperature and time) cannot change the phase composition of the boron steel used in the bars, and has very limited potential for improving the bars' tensile strength, toughness, and wear resistance. Therefore, the traditional horizontal straight line design method and heat treatment process parameter improvement method are obviously difficult to meet the requirements of low running resistance and high service performance (specifically high tensile strength, high toughness and high wear resistance) of the existing reversible plow under high-speed service environment.

[0006] Summary of the Invention

[0007] To address these issues, the present invention provides a method for modeling and manufacturing a reversible plow tip that combines low resistance with internal strength and external rigidity. This method changes the traditional approach to enhancing plow tip performance by integrating methods for optimizing plow tip surface parameters, improving plow tip material composition, and refining the manufacturing process.

[0008] First, the present invention combines mathematical modeling, 3D software modeling, and discrete element simulation analysis to determine the plow blade angle λ0, plow face angle ε, soil trace-plow blade angle η, and soil lift angle θ that minimize working resistance. Compared to traditional plow surface optimization methods, the introduction of 3D modeling and discrete element simulation analysis fully considers more factors affecting plow operation, significantly improving the feasibility of the optimization results.

[0009] Second, by introducing appropriate amounts of Nb, V, and Ni into the composition of existing 34MnCrB5 steel for reversible plow points, this invention produces a new type of 34MnCrB5-M steel with fine grains and uniform microstructure. The combined addition of Nb and V refines the grain size, improves the steel's strength and toughness, reduces overheating sensitivity, and enhances thermal stability. Ni effectively lowers the ductile-brittle transition temperature of 34MnCrB5-M steel, improving the service stability of plow point components under low-temperature conditions.

[0010] On this basis, the present invention improves the manufacturing process of the new 34MnCrB5-M plow tip, and obtains a new 34MnCrB5-M plow tip with significantly improved surface hardness and wear resistance by introducing a new carburizing process (die forging-annealing-machining-carburizing-quenching-tempering-shot peening-spraying), while the core still maintains good strength and toughness matching. It is well known that increasing the C content in steel is a cost-effective method to improve its hardness. However, increasing the C content in steel will also lead to a significant decrease in its toughness after heat treatment, which will cause the plow tip to be easily impacted by sand and gravel during operation and break and fail. The present invention effectively avoids this problem by using a carburizing process, including obtaining a high-hardness and high-wear-resistant carburized layer with a thickness of about 2.5 mm on the surface of the new 34MnCrB5-M plow tip through the carburizing process, while the core material still maintains the base material composition unchanged, to ensure that the plow tip base material has good strength and toughness matching properties to resist the impact of sand and gravel.

[0011] In summary, the method of the present invention effectively ensures that the new 34MnCrB5-M plow tip can withstand high-speed impact from soil and rocks without failure, while also reducing energy consumption by lowering the plow's operating resistance. The technical method employed in this invention is also highly feasible, easily scalable, and low-cost, and is expected to be widely used in fields such as agricultural and mining machinery manufacturing.

[0012] According to another aspect of the present invention, a method for modeling and manufacturing high-speed flip plow fence bars that can improve mechanical properties and reduce resistance is provided.

[0013] First, the present invention determines the optimal surface parameters of the low-resistance bars through the horizontal straight line design method, UG modeling and ANSYS simulation analysis. Significantly different from the traditional bar surface optimization method, this method comprehensively considers factors such as soil parameters, bar material parameters and the contact relationship between the plow body and the soil through UG modeling and ANSYS simulation analysis, greatly improving the working efficiency of the plow body surface optimization process and the feasibility of the optimization scheme. On this basis, the present invention adds appropriate amounts of Al, Nb and Cu elements to the composition design of the existing 28MnB5 steel for flip plow bars, and uses a vacuum induction melting furnace to obtain a new type of 28MnB5-M steel with fine grains and uniform distribution. Among them, the Al element can generate highly fine ultra-micro oxide particles dispersed in the steel to prevent grain growth. The Nb element can generate highly dispersed and strong carbide NbC, which can further prevent grain growth. The Cu element can not only improve the hardenability of steel by enhancing the stability of austenite, but also improve the corrosion resistance of steel. The above alloying idea effectively improves the defects of coarse grains and uneven distribution of the original 28MnB5 steel, and provides a high-quality raw material supply for the subsequent manufacture of high-strength flip plow bars. In addition, the present invention adds hot forming and normalizing processes (machining-hot forming-normalizing-quenching-tempering-shot peening-spraying) to the bar components prepared based on the low-resistance bar modeling scheme and high-quality 28MnB5-M steel. Among them, hot forming is a process of simultaneously using a stamping die to form the bar blank heated to the austenitized state. This not only effectively avoids the generation of microcrack defects in the large deformation parts of the bar blank during cold working, but also greatly reduces the working load of the press during the bar blank forming process, which is more conducive to energy saving. In addition, the normalizing process can make the chemical elements in the 28MnB5-M steel evenly distributed, reduce component segregation, thereby further refining the structure of the 28MnB5-M steel and reducing the content of banded structure in the steel, so as to achieve good strength and toughness matching and high wear resistance of the flip plow bar components. The above-described technical method effectively achieves the production of a new type of high-speed reversible plow fence with low operating resistance, high yield strength, high tensile strength, high toughness, and high wear resistance, and is also more conducive to reducing tractor energy consumption. The technical method used in this invention is highly feasible, easy to promote, and low-cost, and is expected to be widely used in the field of agricultural machinery manufacturing.

[0014] To this end, according to one aspect of the present invention, a method for manufacturing high-speed flip plow fence bars that can improve mechanical properties and reduce resistance is provided, which is characterized by comprising:

[0015] Step XE): preparing a novel 28MnB5-M steel, comprising:

[0016] Step XE1): 0.05% to 0.11% by mass of Nb and 0.04% to 0.10% by mass of Al were added to form the composition of 28MnB5-M steel as shown in Table 1. The alloy was melted in a vacuum induction furnace, cast into a 200 kg ingot, and then forged into a hot-rolled billet of 500 mm × 1000 mm × 50 mm. The units in Table 5 are mass percentages, %.

[0017] Table 5: 28MnB5-M steel composition

[0018] Step XE2): heating the hot-rolled billet to 1100° C. to 1200° C., holding the temperature for 1.8 to 2.0 hours, and then rolling the billet three times after exiting the furnace. The final rolling temperature is 880 to 920° C., and the thickness of the rolled billet is 12 mm.

[0019] Step XE3): Cooling the hot-rolled plate after final rolling to a set coiling temperature of 500° C. to 600° C., then placing it in a heating furnace for 28 to 30 minutes and then cooling it in the furnace;

[0020] Step XF): Machining the grid bar blank, including:

[0021] Step XF1): Cutting the 28MnB5-M hot-rolled plate from step XE3 into bar blanks using an oxyacetylene cutting method;

[0022] Step XF2): Use a milling machine to fine-process the shape of the grid blank.

[0023] Step XF3): using a drilling machine to process a countersunk square hole in the grid bar blank. Step XG): performing a hot forming-normalizing-quenching-tempering treatment on the grid bar, including:

[0024] Step XG1): heating the grid bar blank to 940° C. to 960° C. and keeping the temperature for 1.0 h to 1.2 h;

[0025] Step XG2): After the heat preservation is completed, the grid bar blank is transferred into a stamping die to be formed into a three-dimensional solid grid bar, and after the forming is completed, it is placed in air to cool to room temperature;

[0026] Step XG3): heating the grid bar blank to 900° C. to 920° C. again, keeping the temperature for 0.5 to 0.7 hours, and then immersing the blank in water to quench it to room temperature;

[0027] Step XG4): the quenched grid bar blank is further transferred into a tempering furnace at a temperature of 180° C. to 200° C. and kept at this temperature for 2.0 h to 2.4 h. After the end of the holding period, the grid bar blank is taken out of the furnace and air-cooled.

[0028] The parameters of the three-dimensional solid grid bars are determined by the following steps:

[0029] Step XA): Optimize the bar surface using the horizontal straight line design method, including obtaining the key parameters of the flip plow bar surface according to the following equations (13)-(15): l = C1b (cosΔε-sinε) (13),

[0030] in:

[0031] The plow body width b is 640mm~700mm,

[0032] The value range of the plow blade installation angle ε is 20°~30°.

[0033] Guide curve buckle angle Δ ε The value is between 5° and 11°.

[0034] C1 is a constant, ranging from 1.0 to 1.8.

[0035] The range of the guide curve opening l determined by formula (1)-(3) is 308mm~458mm, the range of the guide curve height h is 550mm~870mm, and the range of the endpoint tangent angle ω is 105°~109°;

[0036] Step XB): Use UG software to create a three-dimensional model of the plow body, including:

[0037] XB1) Select a reference plane and draw the plow edge line and guide curve sketches respectively;

[0038] XB2) combining the bar surface parameters in step XA and using the element line number and the corresponding element line angle calculation formula in formula (16) to draw a horizontal straight element line;

[0039] XB3) Draw a front view of the plow body curve, and project the front view of the plow body curve to obtain a closed space curve;

[0040] XB4) Use the Crop command to cut out the plow body surface, then use the Stretch command to convert the plow body surface into a 3D solid shape and export the .stl model file;

[0041] Where:

[0042] n is the line number; θ is the line angle; θ m and θ n are the element angles when the element number is m and n respectively; θ0 is the initial element angle, which is generally 36°~45°; θ max and θ min The maximum and minimum element line angles respectively; Δ z is the distance between the element lines.

[0043] According to a further aspect of the present invention, the method for manufacturing the high-speed flip plow fence bar further comprises:

[0044] Step XC): Perform preliminary preparation for ANSYS simulation, including:

[0045] Set soil material property parameters: soil density is 1.76~1.78×103kg / m 3 , elastic modulus is 4.3~4.5×107Pa, Poisson's ratio is 0.33~0.35, yield stress is 8.3~8.5×105Pa, tangent modulus is 1.0~1.2×106Pa, failure strain is 0.6~0.8, and strain rate is 4%~6%;

[0046] Set the material characteristic parameters of the flip plow fence: density is 7.79~7.81×10-6kg / mm 3 , elastic modulus is 2.2~2.4×105N / mm 2 , Poisson's ratio is 0.2 to 0.4;

[0047] Set the contact mode between the plow body surface and the soil to automatic contact by surface erosion. Step XD): Perform simulation, including:

[0048] Import the .stl model file in step XB into the ANSYS simulation environment built in step XC, and set the plow body component running speed to 0.36-0.38 m / s and the forward direction to the positive direction of the X axis;

[0049] Enter the simulation settings and set the time step and simulation time to 10s;

[0050] Start the simulation, and after the simulation is completed, obtain the average resistance value of the plow body components.

[0051] According to a further aspect of the present invention, the method for manufacturing high-speed flip plow fence bars further comprises, after step XE3, performing:

[0052] Step XE4): Pickling to remove iron oxide scale on the surface of the hot-rolled plate.

[0053] According to a further aspect of the present invention, the method for manufacturing high-speed flip plow fence bars further comprises, after step XG4, performing:

[0054] Step XG5): Shot peening and plastic spraying are performed to obtain high-speed flip plow bar components with low running resistance, high strength, high toughness and high wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1 shows a flow chart of a preparation method according to one embodiment of the present invention;

[0056] FIG2 shows a curve showing a change in carbon content of a carburized layer of a plow tip component prepared according to Example 1 along the thickness direction;

[0057] FIG3 shows a microstructure photograph of the plow tip component prepared according to Example 1;

[0058] FIG4 shows a comparison of mechanical properties between the plow tip component prepared according to Example 1 and the existing plow tip component;

[0059] FIG5 shows a curve showing a change in carbon content of a carburized layer of a plow tip component prepared according to Example 2 along the thickness direction;

[0060] FIG6 shows a microstructure photograph of the plow tip component prepared according to Example 2;

[0061] FIG7 shows a comparison of mechanical properties between the plow tip component prepared according to Example 2 and the existing plow tip component;

[0062] FIG8 shows a curve showing the carbon content variation along the thickness direction of the carburized layer of the plow tip component prepared according to Example 3;

[0063] FIG9 shows a microstructure photograph of a plow tip component prepared according to Example 3;

[0064] FIG10 shows a comparison of the mechanical properties of the plow tip component prepared according to Example 3 and the existing plow tip component.

[0065] FIG11 shows an assembly diagram of a bar component according to an embodiment of the present invention;

[0066] FIG12 shows a microstructure photograph of a high-speed flip plow bar component prepared according to Example 4 of the present invention;

[0067] FIG13 shows a comparison of the mechanical properties of a high-speed flip plow bar component prepared according to Example 4 of the present invention and existing bars;

[0068] FIG14 shows a microstructure photograph of a high-speed flip plow bar component prepared according to Example 5 of the present invention;

[0069] FIG15 shows a comparison of the mechanical properties of a high-speed flip plow bar component prepared according to Example 5 of the present invention and existing bars;

[0070] FIG16 shows a microstructure photograph of a high-speed flip plow bar component prepared according to Example 6 of the present invention;

[0071] FIG17 shows a comparison of the mechanical properties of the high-speed flip plow bar component prepared according to Example 6 of the present invention and the existing bars. DETAILED DESCRIPTION

[0072] This invention provides a method for modeling and manufacturing a reversible plow tip that combines low resistance with internal strength and external rigidity. First, by combining mathematical modeling, three-dimensional software modeling, and discrete element simulation analysis, the present invention determines the parameters for the plow blade angle λ0, plow face angle ε, the angle between the soil trace and the plow blade η, and the soil lift angle θ that provide the lowest operating resistance. Compared with traditional plow surface optimization methods, the introduction of three-dimensional modeling and discrete element simulation analysis fully considers more factors that affect the plow's operation, significantly improving optimization results.

[0073] Second, by introducing appropriate amounts of Nb, V, and Ni into the composition of existing 34MnCrB5 steel for reversible plow points, this invention produces a new type of 34MnCrB5-M steel with fine grains and uniform microstructure. The combined addition of Nb and V refines the grain size, improves the steel's strength and toughness, reduces overheating sensitivity, and enhances thermal stability. Ni effectively lowers the ductile-brittle transition temperature of 34MnCrB5-M steel, improving the service stability of plow point components under low-temperature conditions.

[0074] On this basis, the present invention improves the manufacturing process of the new 34MnCrB5-M plow tip. By introducing a new carburizing process (die forging-annealing-machining-carburizing-quenching-tempering-shot peening-ploughing), the surface hardness and wear resistance are significantly improved, while the core still maintains a new 34MnCrB5-M plow tip with good strength and toughness matching, thereby effectively ensuring that the new 34MnCrB5-M plow tip can withstand high-speed impacts of soil and stones without failure, and at the same time can achieve the purpose of reducing energy consumption by reducing the operating resistance of the plow body.

[0075] A method for manufacturing a reversible plow tip according to one embodiment of the present invention includes:

[0076] Step 1: Determine the basic parameters. As shown in Equation 1, the parameter selection method is used to establish the plow blade angle λ0 and the soil internal friction angle φ. t The relationship between the soil internal friction angle φ t Usually less than 4°. Therefore, the value range of the plow blade angle λ0 is 40°-45°.

[0077] The relationship between the angle η between the soil trace line and the plow blade, the plow face angle ε, and the soil lifting angle θ is further established, as shown in Equation 2.

[0078] Generally, for the optimization of plow body surface parameters, in order to ensure the overall reliability of the plow body surface, the angle η between the soil trace line and the plow blade is generally set to 16°-24°, and the plow face angle ε is generally set to 30°-40°. Therefore, the value range of the soil lifting angle θ is 18°-30°. tanη=tanθcosε (2)

[0079] Step 2: Create a 3D model. Based on the plow blade angle λ0, plow face angle ε, soil trace line-plow blade angle η, and soil lift angle θ parameters determined in Step 1, use the curve construction command in UG software to generate the main surfaces. Then, perform surface trimming, connection, smoothing, and editing to complete the overall construction and export the .stl model file.

[0080] Step 3: EDEM discrete element simulation preparation. Set the plow material properties: the plow material density is 7800kg / m 3 , the shear modulus is 7.0×10 10 Pa, Poisson's ratio is 0.3; set soil properties: soil density is 2600kg / m 3 , the shear modulus is 2.5×10 7 Pa, Poisson's ratio is 0.5, and the radius of soil particles is 2 mm; set the interaction parameters between soil particles and the plow body's entrapment parts: the static friction factor between soil particles is 0.40, the dynamic friction factor between soil particles is 0.32, the collision recovery coefficient between soil particles is 0.11, the static friction factor between soil particles and the plow body is 0.30, the dynamic friction factor between soil particles and the plow body is 0.22, and the collision recovery coefficient between soil particles and the plow body is 0.18; create a particle factory to generate soil particles.

[0081] Step 4: Simulation. Import the .stl model file from Step 2 into the EDEM software and set the plow component's speed to 3.6-3.8 m / s and its forward direction to the X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds, and the Cell Size to 2.5 R / min. Start the simulation and obtain the average resistance value of the plow component.

[0082] Step 5: Prepare new 34MnCrB5-M steel. Based on the composition design of existing 34MnCrB5 steel, add 0.1-0.3% Nb and 0.1-0.3% V by mass, and use medium frequency induction melting furnace to melt the alloy and cast it into the size of The ingot is heated to 920℃-960℃, kept warm for 1.0h-1.2h, and after being taken out of the furnace, it is subjected to primary rolling and secondary finishing rolling to form an ingot with a size of 34MnCrB5-M bars; cutting the bars into plow tip blanks with a length of 340mm-360mm.

[0083] Table 1 Comparison of chemical composition of new 34MnCrB5-M steel and existing 33MnCrB5 steel (mass fraction, %)

[0084] Step 6: Die Forging and Annealing of the Plow Tip Billet. The 34MnCrB5-M billet from Step 5 is heated in a furnace to 900-950°C. After holding at this temperature for 1-2 hours, it is removed from the furnace and transferred to a die forging machine. After die forging, it is cooled to room temperature in air. The die-forged billet is then transferred to an annealing furnace and heated to 600-650°C. After holding at this temperature for 1-2 hours, it is then cooled to room temperature in the furnace. A cemented carbide layer is then built up on the back of the plow tip.

[0085] Step 7: Plow tip machining. Based on the 3D model data of the plow tip component in step 2, the plow tip is fine-machined using a CNC machine tool according to the drawing requirements.

[0086] Step 8: Carburizing, quenching, and tempering the plow tip. Place the plow tip from Step 7 in a gas carburizing furnace at a temperature of 910°C-930°C for 9-10 hours, with a carbon potential of 1.0%-1.2%. After carburizing, quench the plow tip in quenching oil at 45°C-55°C. After quenching, place the plow tip in a tempering furnace at 180°C-200°C for 1.8-2.0 hours, then air-cool to room temperature. Finally, perform shot peening and plastic spraying.

[0087] Advantages of the present invention include:

[0088] The present invention provides a modeling and manufacturing method for a reversible plow tip that combines low resistance with internal strength and external rigidity. This method changes the traditional single performance enhancement method for plow tips and integrates plow tip surface parameter optimization, plow tip material composition improvement, and manufacturing process improvement methods. This method has the following advantages:

[0089] (1) Based on the plow surface optimization method combining traditional mathematical calculation and three-dimensional modeling, the present invention introduces EDEM discrete element simulation analysis to rationally optimize the design parameters of the tip components of the reversible plow, fully considering parameters such as the soil environment and the contact environment between the plow body and the soil, and effectively reducing the plow body running resistance, the wear of the plow tip components, and the fuel consumption of the tractor.

[0090] (2) The present invention improves the composition design of 34MnCrB5 steel, obtaining a new type of 34MnCrB5-M steel by compositely adding 0.1-0.3% Nb, 0.1-0.3% V, and 0.1-0.3% Ni by mass. As strong carbide-forming elements, Nb and V exist in the steel mostly as fine and dispersed carbides, which can effectively refine the grains of 34MnCrB5-M steel, thereby increasing both the strength and toughness of the steel. Ni can effectively lower the toughness-quenching transition temperature of 34MnCrB5-M steel, improving the service stability of plow tip components under low-temperature conditions. Furthermore, Nb, V, and Ni are environmentally friendly and inexpensive, making them a cost-effective means of improving steel performance.

[0091] (3) The carburizing-quenching-tempering heat treatment process adopted by the present invention is a mature industrial technology and has a lower cost than other surface strengthening technologies (such as plasma spraying and surface remelting). The plow tip after carburizing-quenching-tempering treatment has the performance characteristics of "hard outside and tough inside", which effectively ensures that the new plow tip can withstand the high-speed impact of soil and stones without failure. Therefore, the heat treatment process adopted by the present invention is not only cost-effective, but can also be extended to the field of manufacturing wear-resistant parts for mining machinery, and has broad application prospects.

[0092] To sum up, the modeling and manufacturing method of a reversible plow tip with low resistance and strong inside and hard outside provided by the present invention can not only effectively solve the problems of insufficient wear resistance and large resistance of the existing reversible plow tip during operation, but also has the characteristics of high cost performance and easy promotion. It has important and broad application prospects in the fields of agricultural machinery manufacturing and mining machinery manufacturing.

[0093] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below through examples, but the applicable scope of the present invention is not limited to the following examples.

[0094] Example 1:

[0095] The steps include:

[0096] (1) Design and manufacture of plow points, including:

[0097] Step 1: Establish a mathematical model. As shown in Equation 3, the parameter selection method is used to establish the plow blade angle λ0 and the soil internal friction angle φ t The relationship between the soil internal friction angle φ t Usually it is less than 4°. Therefore, the value range of the plow blade angle λ0 is 40°-45°. In this embodiment, the plow blade angle λ0 is set to 40°.

[0098] The relationship between the angle η between the soil trace and the plow blade, the plow face angle ε, and the soil lifting angle θ is further established, as shown in Equation 4. Generally, for the optimization of the plow body surface parameters, in order to ensure the reliability of the plow body surface as a whole, in this embodiment, the angle η between the soil trace and the plow blade is set to 16°, and the plow face angle ε is set to 30°. Therefore, the soil lifting angle θ is set to 18°. tanη=tanθcosε (4)

[0099] Step 2: Create a 3D model. Based on the plow blade angle λ0, plow face angle ε, soil trace line-plow blade angle η, and soil lift angle θ parameters from Step 1, use the curve construction command in UG software to generate the main surfaces. Then, perform trimming, connecting, smoothing, and editing of the surfaces to complete the overall construction and export the .stl model file.

[0100] Step 3: EDEM discrete element simulation preparation. Set the plow material properties: the plow material density is 7800kg / m 3 , the shear modulus is 7.0×10 10 Pa, Poisson's ratio is 0.3; set soil properties: soil density is 2600kg / m 3 , the shear modulus is 2.5×10 7 Pa, Poisson's ratio is 0.5, and the radius of soil particles is 2 mm; set the interaction parameters between soil particles and the plow body's entrapment parts: the static friction factor between soil particles is 0.40, the dynamic friction factor between soil particles is 0.32, the collision recovery coefficient between soil particles is 0.11, the static friction factor between soil particles and the plow body is 0.30, the dynamic friction factor between soil particles and the plow body is 0.22, and the collision recovery coefficient between soil particles and the plow body is 0.18; create a particle factory to generate soil particles.

[0101] Step 4: Simulation. Import the .stl model file from Step 2 into the EDEM software and set the plow component's speed to 3.6 m / s and its forward direction to the X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds, and set the Cell-Size to 2.5 R / min. Start the simulation. After the simulation is complete, the average resistance value of the plow component is 5.63 kN.

[0102] Step 5: Prepare the new 34MnCrB5-M steel. Based on the existing 34MnCrB5 steel composition design, add 0.1% Nb, 0.1% V and 0.1% Ni by mass, and use a medium frequency induction melting furnace to melt the alloy and cast it into an ingot with a size of φ100mm×500mm. Heat the ingot to 920℃ and keep it warm for 1.0h. After it is taken out of the furnace, it undergoes primary rolling and secondary finishing rolling to form a 34MnCrB5-M steel. 34MnCrB5-M bars; the bars are cut into plow tip blanks with a length of 340 mm.

[0103] Table 2 Comparison of chemical composition of new 34MnCrB5-M steel and existing 33MnCrB5 steel (mass fraction, %)

[0104] Step 6: Die Forging and Annealing of the Plow Tip Billet. The 34MnCrB5-M billet from Step 5 is heated to 900°C in a heating furnace and held at this temperature for 1.0 hour. It is then removed from the furnace and transferred to a die forging machine. After die forging, it is cooled to room temperature in air. The die-forged billet is then transferred to an annealing furnace and heated to 600°C, held at this temperature for 1.0 hour, and then cooled to room temperature in the furnace. A cemented carbide layer is then built up on the back of the plow tip.

[0105] Step 7: Plow tip machining. Based on the 3D model data of the plow tip component in step 2, the plow tip is fine-machined using a CNC machine tool according to the drawing requirements.

[0106] Step 8: Carburizing, quenching, and tempering the plow tip. Place the plow tip from Step 7 in a gas carburizing furnace at 910°C for 9.0 hours and a carbon potential of 1.0%. After carburizing, quench the plow tip in quenching oil at 45°C. After quenching, place the plow tip in a tempering furnace at 180°C for 1.8 hours, then air cool to room temperature. Finally, perform shot peening and plastic spraying.

[0107] (2) Alloy testing

[0108] The carbon content of the carburized layer at the plow tip of the new 33MnCrB5-M alloy along its thickness was measured using a SPECTRO direct-reading spectrometer. The test results are shown in Figure 2. It can be seen that the carbon content of the carburized layer at the plow tip of the new 33MnCrB5-M alloy in this example first decreases with increasing distance from the surface and then approaches a constant. The maximum carbon content near the surface is 0.70 wt.%, while the carbon content in the core is 0.34 wt.%.

[0109] The microstructure of the surface layer of the new 33MnCrB5-M plow tip was observed using a FEI Nova Nano450 field emission scanning electron microscope and a Leica optical microscope, as shown in Figure 3. It can be seen that the surface layer of the 33MnCrB5-M plow tip is composed of acicular martensite + retained austenite + carbides. The acicular martensite is small and evenly distributed, with an average length of approximately 5.4 μm.

[0110] A comparison of the mechanical properties of the new 33MnCrB5-M plow point in this embodiment and existing plow points is shown in Figure 4. As can be seen, the new 33MnCrB5-M plow point has a yield strength of 1347 MPa and a tensile strength of 1814 MPa. The surface hardness of the new 33MnCrB5-M plow point material is 59.7 HRC. Thanks to the high surface hardness of the plow point material, the surface wear of the new 33MnCrB5-M plow point is only 0.8 mg. The impact energy absorbed by the core material of the new 33MnCrB5-M plow point is 57.3 J, indicating that the core of the new 33MnCrB5-M plow point achieves high toughness. Furthermore, compared with existing plow points, the new 33MnCrB5-M plow point in this embodiment not only significantly improves yield strength, tensile strength, hardness, wear resistance, and toughness, but also reduces operating resistance during operation.

[0111] The above testing and characterization demonstrate that the new 33MnCrB5-M plow point of this embodiment maintains a good balance of strength and toughness at the core while also exhibiting high surface hardness and wear resistance. Furthermore, after optimizing the curved surface design parameters, the new 33MnCrB5-M plow point exhibits low resistance, potentially finding significant applications in agricultural machinery and advanced industries.

[0112] Example 2:

[0113] The steps include:

[0114] (1) Design and manufacture of plow points, including:

[0115] Step 1: Establish a mathematical model. As shown in Equation 5, the parameter selection method is used to establish the plow blade angle λ0 and the soil internal friction angle φ t The relationship between the soil internal friction angle φ t Usually it is less than 4°. Therefore, the value range of the plow blade angle λ0 is 40°-45°. In this embodiment, the value of the plow blade angle λ0 is 42.5°.

[0116] The relationship between the angle η between the soil trace and the plow blade, the plow face angle ε, and the soil lifting angle θ is further established, as shown in (6). For the optimization of the plow body surface parameters, in order to ensure the reliability of the plow body surface as a whole, in this embodiment, the angle η between the soil trace and the plow blade is set to 20°, and the plow face angle ε is set to 35°. Therefore, the soil lifting angle θ is set to 24°. tanη=tanθcosε (6)

[0117] Step 2: Create a 3D model. Based on the plow blade angle λ0, plow face angle ε, soil trace line-plow blade angle η, and soil lift angle θ parameters from Step 1, use the curve construction command in UG software to generate the main surfaces. Then, perform trimming, connecting, smoothing, and editing of the surfaces to complete the overall construction and export the .stl model file.

[0118] Step 3: EDEM discrete element simulation preparation. Set the plow material properties: the plow material density is 7800kg / m 3 , the shear modulus is 7.0×10 10 Pa, Poisson's ratio is 0.3; set soil properties: soil density is 2600kg / m 3 , the shear modulus is 2.5×10 7 Pa, Poisson's ratio is 0.5, and the radius of soil particles is 2 mm; set the interaction parameters between soil particles and the plow body's entrapment parts: the static friction factor between soil particles is 0.40, the dynamic friction factor between soil particles is 0.32, the collision recovery coefficient between soil particles is 0.11, the static friction factor between soil particles and the plow body is 0.30, the dynamic friction factor between soil particles and the plow body is 0.22, and the collision recovery coefficient between soil particles and the plow body is 0.18; create a particle factory to generate soil particles.

[0119] Step 4: Simulate. Import the .stl model file from Step 2 into the EDEM software and set the plow component's speed to 3.7 m / s and its forward direction to the X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds, and the Cell Size to 2.5 R / min. Start the simulation. After completion, the average resistance value of the plow component is 5.03 kN.

[0120] Step 5: Prepare new 34MnCrB5-M steel. Based on the composition design of the existing 34MnCrB5 steel, add 0.2% Nb, 0.2% V and 0.2% Ni by mass, and use a medium frequency induction melting furnace to melt the alloy and cast it into a size of The ingot is heated to 940℃ and kept warm for 1.1h. After being taken out of the furnace, it is subjected to primary rolling and secondary finishing rolling to form an ingot with a size of 34MnCrB5-M bars; the bars are cut into plow tip blanks with a length of 350 mm.

[0121] Table 3 Comparison of chemical composition of new 34MnCrB5-M steel and existing 33MnCrB5 steel (mass fraction, %)

[0122] Step 6: Die Forging and Annealing of the Plow Tip Billet. The 34MnCrB5-M billet from Step 5 is heated to 925°C in a heating furnace, held at this temperature for 1.5 hours, then removed from the furnace and transferred to a die forging machine. After die forging, the billet is cooled to room temperature in air. The die-forged billet is then transferred to an annealing furnace, heated to 625°C, held at this temperature for 1.5 hours, and then cooled to room temperature in the furnace. A cemented carbide layer is then built up on the back of the plow tip.

[0123] Step 7: Plow tip machining. Based on the 3D model data of the plow tip component in step 2, the plow tip is fine-machined using a CNC machine tool according to the drawing requirements.

[0124] Step 8: Carburizing, quenching, and tempering the plow tip. The plow tip blank from Step 7 is placed in a gas carburizing furnace at 920°C for 9.5 hours, with a carbon potential of 1.1%. After carburizing, the plow tip is quenched in quenching oil at 50°C. After quenching, the plow tip is placed in a tempering furnace at 190°C for 1.9 hours, then air-cooled to room temperature. Finally, shot peening and plastic spraying are performed.

[0125] (2) Alloy testing

[0126] The carbon content of the carburized layer at the plow tip of the new 33MnCrB5-M alloy along the thickness direction was measured using a SPECTRO direct-reading spectrometer. The test results are shown in Figure 5. It can be seen that the carbon content of the carburized layer at the plow tip of the new 33MnCrB5-M alloy in this example first decreases with increasing distance from the surface and then approaches a constant. The maximum carbon content near the surface is 0.73 wt.%, while the carbon content in the core is 0.34 wt.%.

[0127] The microstructure of the surface of the new 33MnCrB5-M plow tip was observed using a FEI Nova Nano450 field emission scanning electron microscope and a Leica optical microscope, as shown in Figure 6. It can be seen that the surface of the 33MnCrB5-M plow tip is composed of acicular martensite + retained austenite + carbides. The acicular martensite is small and evenly distributed, with an average length of approximately 5.0 μm.

[0128] A comparison of the mechanical properties of the new 33MnCrB5-M plow point in this embodiment and existing plow points is shown in Figure 7. As can be seen, the new 33MnCrB5-M plow point has a yield strength of 1393 MPa and a tensile strength of 1871 MPa. The surface hardness of the new 33MnCrB5-M plow point material is 60.2 HRC. Thanks to the high surface hardness of the plow point material, the surface wear of the new 33MnCrB5-M plow point is only 0.7 mg. The impact energy absorbed by the core material of the new 33MnCrB5-M plow point is 58.2 J, indicating that the core of the new 33MnCrB5-M plow point achieves high toughness. Furthermore, compared with existing plow points, the new 33MnCrB5-M plow point in this embodiment not only significantly improves yield strength, tensile strength, hardness, wear resistance, and toughness, but also reduces operating resistance during operation.

[0129] The above testing and characterization demonstrate that the new 33MnCrB5-M plow point of this embodiment maintains a good balance of strength and toughness at the core while also exhibiting high surface hardness and wear resistance. Furthermore, after optimizing the curved surface design parameters, the new 33MnCrB5-M plow point exhibits low resistance, potentially finding significant applications in agricultural machinery and advanced industries.

[0130] Example 3:

[0131] The steps include:

[0132] (1) Design and manufacture of plow points, including:

[0133] Step 1: Establish a mathematical model. As shown in Equation 7, the parameter selection method is used to establish the plow blade angle λ0 and the soil internal friction angle φ t The relationship between the soil internal friction angle φ t Usually it is less than 4°. Therefore, the value range of the plow blade angle λ0 is 40°-45°. In this embodiment, the value of the plow blade angle λ0 is 45°.

[0134] The relationship between the angle η between the soil trace and the plow blade, the plow face angle ε, and the soil lifting angle θ is further established, as shown in Equation 8. Generally, for the optimization of the plow body surface parameters, in order to ensure the reliability of the plow body surface as a whole, in this embodiment, the angle η between the soil trace and the plow blade is set to 24°, and the plow face angle ε is set to 40°. Therefore, the soil lifting angle θ is set to 30°. tanη=tanθcosε (8)

[0135] Step 2: Create a 3D model. Based on the plow blade angle λ0, plow face angle ε, soil trace line-plow blade angle η, and soil lift angle θ parameters from Step 1, use the curve construction command in UG software to generate the main surfaces. Then, perform trimming, connecting, smoothing, and editing of the surfaces to complete the overall construction and export the .stl model file.

[0136] Step 3: EDEM discrete element simulation preparation. Set the plow material properties: the plow material density is 7800kg / m 3 , the shear modulus is 7.0×10 10 Pa, Poisson's ratio is 0.3; set soil properties: soil density is 2600kg / m 3 , the shear modulus is 2.5×10 7 Pa, Poisson's ratio is 0.5, and the radius of soil particles is 2 mm; set the interaction parameters between soil particles and the plow body's entrapment parts: the static friction factor between soil particles is 0.40, the dynamic friction factor between soil particles is 0.32, the collision recovery coefficient between soil particles is 0.11, the static friction factor between soil particles and the plow body is 0.30, the dynamic friction factor between soil particles and the plow body is 0.22, and the collision recovery coefficient between soil particles and the plow body is 0.18; create a particle factory to generate soil particles.

[0137] Step 4: Simulate. Import the .stl model file from Step 2 into the EDEM software and set the plow component's speed to 3.8 m / s and its forward direction to the X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds, and the Cell Size to 2.5 R / min. Start the simulation. After completion, the average resistance value of the plow component is 5.53 kN.

[0138] Step 5: Prepare new 34MnCrB5-M steel. Based on the composition design of the existing 34MnCrB5 steel, add 0.3% Nb, 0.3% V and 0.3% Ni by mass fraction, and use a medium frequency induction melting furnace to melt the alloy and cast it into a size of The ingot is heated to 960℃ and kept warm for 1.2h. After being taken out of the furnace, it is subjected to primary rolling and secondary finishing rolling to form an ingot with a size of 34MnCrB5-M bars; the bars are cut into plow tip blanks with a length of 360 mm.

[0139] Table 4 Comparison of chemical composition of new 34MnCrB5-M steel and existing 33MnCrB5 steel (mass fraction, %)

[0140] Step 6: Die Forging and Annealing of the Plow Tip Billet. The 34MnCrB5-M billet from Step 5 is heated to 950°C in a heating furnace, held at this temperature for 2.0 hours, then removed from the furnace and transferred to a die forging machine. After die forging, the billet is air-cooled to room temperature. The die-forged billet is then transferred to an annealing furnace, heated to 650°C, held at this temperature for 2.0 hours, and then cooled to room temperature in the furnace. A cemented carbide layer is then built up on the back of the plow tip.

[0141] Step 7: Plow tip machining. Based on the 3D model data of the plow tip component in step 2, the plow tip is fine-machined using a CNC machine tool according to the drawing requirements.

[0142] Step 8: Carburizing, quenching, and tempering the plow tip. Place the plow tip from Step 7 in a gas carburizing furnace at 930°C for 10 hours, with a carbon potential of 1.2%. After carburizing, quench the plow tip in quenching oil at 55°C. After quenching, place the plow tip in a tempering furnace at 200°C for 2 hours, then air cool to room temperature. Finally, perform shot peening and plastic spraying.

[0143] (2) Alloy testing

[0144] The carbon content of the carburized layer at the plow tip of the new 33MnCrB5-M alloy along the thickness direction was measured using a SPECTRO direct-reading spectrometer. The test results are shown in Figure 8. It can be seen that the carbon content of the carburized layer at the plow tip of the new 33MnCrB5-M alloy in this example first decreases with increasing distance from the surface and then approaches a constant. The maximum carbon content near the surface is 0.72 wt.%, while the carbon content in the core is 0.34 wt.%.

[0145] The microstructure of the surface layer of the new 33MnCrB5-M plow tip was observed using a FEI Nova Nano450 field emission scanning electron microscope and a Leica optical microscope, as shown in Figure 9. It can be seen that the surface layer of the 33MnCrB5-M plow tip is composed of acicular martensite + retained austenite + carbides. The acicular martensite is small and evenly distributed, with an average length of approximately 5.3 μm.

[0146] A comparison of the mechanical properties of the new 33MnCrB5-M plow point in this embodiment and existing plow points is shown in Figure 10. As can be seen, the new 33MnCrB5-M plow point has a yield strength of 1344 MPa and a tensile strength of 1803 MPa. The surface hardness of the new 33MnCrB5-M plow point material is 59.1 HRC. Thanks to the high surface hardness of the plow point material, the surface wear of the new 33MnCrB5-M plow point is only 0.8 mg. The impact absorption energy of the core material of the new 33MnCrB5-M plow point is 58.0 J, indicating that the core of the new 33MnCrB5-M plow point achieves high toughness. Furthermore, compared with existing plow points, the new 33MnCrB5-M plow point in this embodiment not only significantly improves yield strength, tensile strength, hardness, wear resistance, and toughness, but also reduces operating resistance during operation.

[0147] The above testing and characterization demonstrate that the new 33MnCrB5-M plow point of this embodiment maintains a good balance of strength and toughness at the core while also exhibiting high surface hardness and wear resistance. Furthermore, after optimizing the curved surface design parameters, the new 33MnCrB5-M plow point exhibits low resistance, potentially finding significant applications in agricultural machinery and advanced industries.

[0148] According to another aspect of the present invention, in order to solve the problems of excessive resistance and insufficient service life of existing high-speed reversible plow fences during service, the present invention provides a modeling and manufacturing method for high-speed reversible plow fences that can improve mechanical properties and reduce resistance. First, the present invention determines the optimal surface parameters of low-resistance bars through horizontal straight line design method, UG modeling and ANSYS simulation analysis. Significantly different from traditional bar surface optimization methods, this method comprehensively considers factors such as soil parameters, bar material parameters and the contact relationship between the plow body and the soil through UG modeling and ANSYS simulation analysis, greatly improving the work efficiency of the plow body surface optimization process and the feasibility of the optimization scheme. On this basis, the present invention adds appropriate amounts of Al, Nb and Cu elements to the composition design of the existing 28MnB5 steel for reversible plow fences, and uses a vacuum induction melting furnace to obtain a new type of 28MnB5-M steel with fine and uniform grains. Among them, the Al element can generate highly fine ultra-micro oxide particles dispersed in the steel to prevent grain growth. The Nb element can generate highly dispersed and strong carbide NbC, which can further prevent grain growth. The Cu element can not only improve the hardenability of steel by enhancing the stability of austenite, but also improve the corrosion resistance of steel. The above alloying idea effectively improves the defects of coarse grains and uneven distribution of the original 28MnB5 steel, and provides a high-quality raw material supply for the subsequent manufacture of high-strength flip plow bars. In addition, the present invention adds a hot forming and normalizing process (machining-hot forming-normalizing-quenching-tempering-shot peening-spraying) to the bar components prepared based on the low-resistance bar modeling scheme and high-quality 28MnB5-M steel. Among them, hot forming is a process of using a stamping die to simultaneously form the bar blank heated to the austenitized state. This not only effectively avoids the generation of microcrack defects in the large deformation parts of the bar blank during cold working, but also greatly reduces the workload of the press during the bar blank forming process, which is more conducive to energy saving. Furthermore, the normalizing process evenly distributes the chemical elements in the 28MnB5-M steel, reducing component segregation. This further refines the 28MnB5-M steel's microstructure and reduces the amount of banded structure within the steel, achieving excellent strength-toughness matching and high wear resistance in the reversing plow bar components. This technical approach effectively enables the manufacture of new high-speed reversing plow bars with low operating resistance, excellent strength-toughness matching, and high wear resistance, further contributing to the goal of reducing tractor energy consumption. It is expected to provide a viable technical solution for ensuring the safe and long-life operation of agricultural machinery soil-contacting components.

[0149] According to one embodiment of the present invention, a modeling and manufacturing method for a high-speed flip plow fence capable of improving mechanical properties and reducing resistance includes:

[0150] Step XA): Optimize the bar surface using the horizontal straight line design method. In order to improve the plow's ability to turn over the soil, reduce the friction between the bar and the soil, and reduce the plow's loss, the present invention calculates the key parameters of the flip plow bar surface according to formulas 1-3. Among them, the plow width b is generally 640mm to 700mm; the plow blade installation angle ε ranges from 20° to 30°, and the guide curve buckle angle Δ ε It is usually between 5° and 11°. C1 is a constant, usually between 1.0 and 1.8. According to formula 1-3, the range of the guide curve opening l is 308mm to 458mm, the range of the guide curve height h is 550mm to 870mm, and the range of the endpoint tangent angle ω is 105° to 109°; l = C1b (cosΔε-sinε) (9)

[0151] Step XB): Use UG software to build a 3D model of the plow body, including

[0152] B1) Select a reference plane and sketch the plow edge and guide curve respectively;

[0153] B2) combining the bar surface parameters in step XA and using the element line number and the corresponding element line angle calculation formula in formula (12) to draw a horizontal straight element line;

[0154] B3) Draw a front view of the plow body curve, and project the front view of the plow body curve to obtain a closed space curve;

[0155] B4) Use the Crop command to cut out the plow body surface, then use the Stretch command to transform the plow body surface into a 3D solid shape (as shown in Figure 17), and export the .stl model file;

[0156] Where: n is the number of the element line; θ is the element line angle; θ m and θ n are the element angles when the element number is m and n respectively; θ0 is the initial element angle, which is generally 36°~45°; θ max and θ min The maximum and minimum element line angles respectively; Δ z is the distance between element lines;

[0157] Step XC): Perform preliminary preparation for ANSYS simulation, including:

[0158] Set soil material property parameters: soil density is 1.76~1.78×103kg / m 3, elastic modulus is 4.3~4.5×107Pa, Poisson's ratio is 0.33~0.35, yield stress is 8.3~8.5×105Pa, tangent modulus is 1.0~1.2×106Pa, failure strain is 0.6~0.8, and strain rate is 4%~6%;

[0159] Set the material characteristic parameters of the flip plow fence: density is 7.79~7.81×10-6kg / mm 3 , elastic modulus is 2.2~2.4×105N / mm 2 , Poisson's ratio is 0.2 to 0.4;

[0160] Set the contact mode between the plow body surface and the soil to automatic contact by surface erosion. Step XD): Perform simulation, including:

[0161] Import the .stl model file in step XB into the ANSYS simulation environment built in step XC, and set the plow body component running speed to 0.36-0.38 m / s and the forward direction to the positive direction of the X axis;

[0162] Enter the simulation settings and set the time step and simulation time to 10s;

[0163] The simulation is started, and after the simulation is completed, the average resistance value of the plow body components is obtained. Step XE): preparing the new 28MnB5-M steel, including:

[0164] Based on the existing 28MnB5 steel composition design, 0.05% to 0.11% Nb and 0.04% to 0.10% Al were added (see Table 1 for details). The alloy was melted in a vacuum induction furnace, cast into 200kg ingots, and then forged into 500mm×1000mm×50mm hot-rolled billets.

[0165] The hot rolled billet is heated to 1100℃~1200℃, kept at this temperature for 1.8h~2.0h, and then rolled for 3 passes after being taken out of the furnace. The final rolling temperature is 880℃~920℃, and the thickness of the rolled sheet is 12mm.

[0166] The plate after final rolling is water-cooled to the set coiling temperature of 500℃~600℃, then placed in the heating furnace for 28min~30min and then cooled with the furnace;

[0167] Finally, pickling is done to remove the iron oxide scale on the surface of the hot rolled plate.

[0168] Table 5 Comparison of chemical composition of new 28MnB5-M steel and existing 28MnB5 steel (mass fraction, %)

[0169] Step XF): Machining the grid bar blank, specifically comprising:

[0170] Cutting the 28MnB5-M hot-rolled plate in step XE into bar blanks using an oxyacetylene cutting method;

[0171] Use milling machine to finish the shape of the grid blank,

[0172] Use a drilling machine to process the countersunk square holes in the grid blank.

[0173] Step XG): performing a hot forming-normalizing-quenching-tempering treatment on the grid bars, specifically comprising:

[0174] Heat the bar blank in step XF to 940°C to 960°C and keep it at this temperature for 1.0h to 1.2h;

[0175] After the heat preservation is completed, the grid bar blank is transferred to a stamping die and formed into the three-dimensional solid shape required in step XB. After the forming is completed, it is placed in air to cool to room temperature;

[0176] Heat the bar blank to 900℃~920℃ again, keep it at this temperature for 0.5h~0.7h, then immerse it in water and quench it to room temperature;

[0177] The quenched grid bar blank is further transferred into a tempering furnace at a temperature of 180°C to 200°C for 2.0h to 2.4h, and then taken out of the furnace for air cooling after the end of the tempering.

[0178] Shot peening and plastic spraying are carried out to obtain high-speed flip plow bar components with low running resistance, high strength, high toughness and high wear resistance.

[0179] Advantages of the present invention include:

[0180] This invention provides a modeling and manufacturing method for high-speed reversible plow fences that improve mechanical properties and reduce drag. This method utilizes a combination of horizontal straight line design, UG modeling, and ANSYS simulation analysis to determine the optimal surface parameters for the low-drag fences. Targeted improvements are then made to the composition of the 28MnB5 steel used for the fences and the manufacturing process. The advantages of this invention include:

[0181] (1) Significantly different from the previous method of optimizing the bar surface only through mathematical model calculation, the present invention combines the horizontal straight line design method, UG modeling and ANSYS simulation analysis method to rationally optimize the design parameters of the high-speed flip plow bar components. At the same time, factors such as soil parameters, bar material parameters and the contact relationship between the plow body and the soil are introduced, which greatly improves the working efficiency of the plow body surface optimization process and the feasibility of the optimization scheme, effectively reduces the plow body running resistance, and further reduces the impact force of the soil on the bar components and the fuel consumption of the tractor.

[0182] (2) The present invention improves the composition design of 28MnB5 steel and obtains a new type of 28MnB5-M steel by compositely adding 0.05-0.11% Nb, 0.04-0.10% Al and 0.10-0.20% Cu elements by mass. The composite addition of Nb and Al generates highly fine oxides that can prevent grain growth when the steel is heated, further improving the strength and toughness matching of the new type of 28MnB5-M steel after heat treatment. The Cu element can not only improve the hardenability of the steel by enhancing the stability of austenite, but also improve the corrosion resistance of the steel. Compared with the method of adding expensive rare earth elements, the price of the Nb, Al and Cu elements used in the present invention is significantly reduced, and the performance also meets the needs of the industry. It is one of the most economical and effective means to improve the performance of steel.

[0183] (3) The industrialization technology of the hot forming-normalizing-quenching-tempering heat treatment process adopted by the present invention is mature and can be implemented on the basis of existing production equipment without adding other heat treatment equipment, which can greatly reduce costs. At the same time, the organizational size and uniformity of the bar components after the hot forming-normalizing-quenching-tempering treatment are significantly better than those of the previous bar components, which makes it have good strength and toughness matching performance, effectively ensuring that the bars can withstand the high-speed impact of soil and stones without failure. Therefore, the heat treatment process adopted by the present invention has a high cost performance and has broad application prospects in the field of plow body manufacturing.

[0184] To sum up, the modeling and manufacturing method of high-speed reversible plow bars provided by the present invention, which can improve mechanical properties and reduce resistance, can not only effectively solve the problems of insufficient strength and toughness matching and large resistance of existing high-speed reversible plow bars during operation, but also has high cost-effectiveness and has important and broad application prospects in the field of agricultural machinery manufacturing.

[0185] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below through examples, but the applicable scope of the present invention is not limited to the following examples.

[0186] Example 4:

[0187] The steps include:

[0188] (1) Design and manufacture of gratings, including:

[0189] Step X1: Optimize the bar surface using the horizontal straight line design method. To improve the plow's ability to turn over the soil, reduce friction between the bars and the soil, and reduce plow wear, this embodiment calculates the key parameters of the plow bar surface using equations 5-7. The plow width b is 640 mm; the plow blade installation angle ε is 20°; the guide curve buckle angle Δ is 1 / 2. εThe value is 5°, C1 is a constant, and the value is 1.0. According to formula 5-7, the value of the guide curve opening l is 308mm, the value of the guide curve height h is 550mm, and the value of the end point tangent angle ω is 105°. l=C1b(cosΔε-sinε) (13)

[0190] Step X2: Use UG software to create a 3D model of the plow body. First, select a reference plane and sketch the plow blade and guide curves. Then, combine the bar surface parameters from Step X1 with the line number and corresponding line angle calculation formula in Equation 16 to draw horizontal straight lines. Finally, draw the front view of the plow body curve and project it to obtain a closed spatial curve. Then, use the Crop command to crop the plow body surface. Then, use the Extrude command to convert the plow body surface into a 3D solid shape and export the .stl model file.

[0191] Where: n is the number of the element line; θ is the element line angle; θ m and θ n are the element angles when the element number is m and n respectively; θ0 is the initial element angle, which is generally 36°~45°; θ max and θ min The maximum and minimum element line angles respectively; Δ z is the distance between element lines;

[0192] Step X3: ANSYS simulation preparation. Set soil material property parameters: soil density is 1.76×103kg / m 3 , elastic modulus is 4.3×107Pa, Poisson's ratio is 0.33, yield stress is 8.3×105Pa, tangent modulus is 1.0×106Pa, failure strain is 0.6, strain rate is 4%; set the material characteristic parameters of the flip plow fence: density is 7.79×10-6kg / mm 3 , elastic modulus is 2.2×105N / mm 2 , Poisson's ratio is 0.2; the contact mode between the plow surface and the soil is set to automatic contact by surface erosion.

[0193] Step X4: Simulation. Import the .stl model file from Step X2 into the ANSYS simulation environment built in Step X3. Set the plow component speed to 0.36 m / s and the forward direction to the positive X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds. Start the simulation. After the simulation is complete, the average resistance value of the plow component is 4.98 kN.

[0194] Step X5: Preparation of the new 28MnB5-M steel. Based on the existing 28MnB5 steel composition, 0.05% Nb, 0.04% Al, and 0.10% Cu (see Table 2) were added. The alloy was melted in a vacuum induction furnace, cast into a 200 kg ingot, and then forged into a 500 mm × 1000 mm × 50 mm hot-rolled billet. The billet was heated to 1100°C and held at that temperature for 1.8 hours. After removal from the furnace, it was rolled in three passes, with a final rolling temperature of 880°C, resulting in a 12 mm thick plate. The finished plate was water-cooled to the set coiling temperature of 500°C, then placed in a heating furnace, held at that temperature for 28 minutes, and then cooled. Finally, the hot-rolled plate was pickled to remove surface scale.

[0195] Table 6 Comparison of chemical composition of new 28MnB5-M steel and existing 28MnB5 steel (mass fraction, %)

[0196] Step X6: Machining the Bar Blanks: Use oxyacetylene cutting to cut the 28MnB5-M hot-rolled plate from Step X5 into bar blanks. Use a milling machine to fine-machine the bar shape, and use a drilling machine to machine the countersunk square holes for the bars.

[0197] Step X7: Hot forming - normalizing - quenching - tempering treatment of bars. Heat the bar blank in step X6 to 940℃ and keep it warm for 1.0h; after the insulation is completed, transfer the bar blank into a stamping die to form it into the three-dimensional solid shape required in step X2, and after the molding is completed, place it in the air to cool to room temperature; heat the bar blank to 900℃ again, keep it warm for 0.5h, and then immerse it in water to quench it to room temperature; further transfer the quenched bar blank into a tempering furnace with a temperature of 180℃ and keep it warm for 2.0h, and after the insulation is completed, take it out of the furnace and air cool it. Then perform shot peening and plastic spraying to obtain a high-speed flip plow bar component with low running resistance, high strength, high toughness and high wear resistance.

[0198] (2) Alloy testing

[0199] The microstructure of the new 28MnB5-M bars was observed using a FEI Nova Nano 450 field emission scanning electron microscope and an optical microscope, as shown in Figure 12. It can be seen that the structure of the 28MnB5-M bars is mainly composed of fine and evenly distributed lath martensite with an average length of about 4.6 μm.

[0200] Under room temperature conditions, the wear loss of the new 28MnB5-M grating was 1.5 mg when tested using an MFT-R4000 high-speed reciprocating friction and wear tester.

[0201] A comparison of the mechanical performance parameters of the new 28MnB5-M bars of this embodiment and existing bars is shown in Figure 13. It can be seen that the yield strength of the new 28MnB5-M bars of this embodiment is 1308 MPa and the tensile strength is 1608 MPa. The impact energy absorbed by the new 28MnB5-M bars is 56.0 J. Combined with the tensile strength data analysis, it can be seen that the new 28MnB5-M bars achieve an excellent balance of strength and toughness. In addition, compared with existing bars, the new 28MnB5-M bars of this embodiment not only have significantly higher yield strength, tensile strength, and toughness, but also have reduced operating resistance during operation.

[0202] The above tests and characterizations demonstrate that the new 28MnB5-M bar components of this embodiment exhibit excellent strength-toughness matching. Furthermore, the new 28MnB5-M bars, after optimizing the curved design parameters, also exhibit low resistance, potentially finding significant applications in agricultural machinery and advanced industry.

[0203] Example 5:

[0204] The steps include:

[0205] (1) Design and manufacture of gratings, including:

[0206] Step X1: Optimize the bar surface using the horizontal straight line design method. To improve the plow's ability to turn over the soil, reduce friction between the bars and the soil, and reduce plow wear, this embodiment calculates the key parameters of the flip plow bar surface using equations 9-11. The plow width b is 670 mm; the plow blade installation angle ε is 25°; the guide curve buckle angle Δ is 1 / 2. ε The value is 8°, C1 is a constant, and the value is 1.4. According to formula 9-11, the value of the guide curve opening l is 383mm, the value of the guide curve height h is 710mm, and the value of the end point tangent angle ω is 107°. l=C1b(cosΔε-sinε) (17)

[0207] Step X2: Use UG software to create a 3D model of the plow body. First, select a reference plane and sketch the plow blade and guide curves. Then, combine the bar surface parameters from Step X1 with the line number and corresponding line angle calculation formula in Equation 20 to draw horizontal straight lines. Finally, draw the front view of the plow body curve and project it to obtain a closed spatial curve. Then, use the Crop command to crop the plow body surface. Then, use the Extrude command to convert the plow body surface into a 3D solid shape and export the .stl model file.

[0208] Where: n is the number of the element line; θ is the element line angle; θ m and θ n are the element angles when the element number is m and n respectively; θ0 is the initial element angle, which is generally 36°~45°; θ max and θ min The maximum and minimum element line angles respectively; Δ z is the distance between element lines;

[0209] Step X3: ANSYS simulation preparation. Set soil material property parameters: soil density is 1.77×103kg / m 3 , elastic modulus is 4.4×107Pa, Poisson's ratio is 0.34, yield stress is 8.4×105Pa, tangent modulus is 1.1×106Pa, failure strain is 0.7, strain rate is 5%; set the material characteristic parameters of the flip plow fence: density is 7.80×10-6kg / mm 3 , elastic modulus is 2.3×105N / mm 2 , Poisson's ratio is 0.3; the contact mode between the plow surface and the soil is set to automatic contact by surface erosion.

[0210] Step X4: Simulation. Import the .stl model file from Step X2 into the ANSYS simulation environment built in Step X3. Set the plow component speed to 0.37 m / s and the forward direction to the positive X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds. Start the simulation. After the simulation is complete, the average resistance value of the plow component is 4.81 kN.

[0211] Step X5: Preparation of a new 28MnB5-M steel. Based on the existing 28MnB5 steel composition, 0.08% Nb, 0.07% Al, and 0.15% Cu (see Table 3) were added. The alloy was melted in a vacuum induction furnace, cast into a 200 kg ingot, and then forged into a 500 mm × 1000 mm × 50 mm hot-rolled billet. The billet was heated to 1150°C and held at that temperature for 1.9 hours. After removal from the furnace, it was rolled in three passes, with a final rolling temperature of 900°C, resulting in a 12 mm thick plate. The finished plate was water-cooled to the set coiling temperature of 550°C, then placed in a heating furnace, held at that temperature for 29 minutes, and then cooled. Finally, the hot-rolled plate was pickled to remove surface scale.

[0212] Table 7 Comparison of chemical composition of new 28MnB5-M steel and existing 28MnB5 steel (mass fraction, %)

[0213] Step X6: Machining the Bar Blanks: Use oxyacetylene cutting to cut the 28MnB5-M hot-rolled plate from Step X5 into bar blanks. Use a milling machine to fine-machine the bar shape, and use a drilling machine to machine the countersunk square holes for the bars.

[0214] Step X7: Hot forming - normalizing - quenching - tempering treatment of bars. Heat the bar blank in step X6 to 950℃ and keep it warm for 1.1h; after the insulation is completed, transfer the bar blank into a stamping die to form it into the three-dimensional solid shape required in step X2, and after the molding is completed, place it in the air to cool to room temperature; heat the bar blank to 910℃ again, keep it warm for 0.6h, and then immerse it in water to quench it to room temperature; further transfer the quenched bar blank into a tempering furnace with a temperature of 190℃ and keep it warm for 2.2h, and after the insulation is completed, take it out of the furnace and air cool it. Then perform shot peening and plastic spraying to obtain a high-speed flip plow bar component with low running resistance, high strength, high toughness and high wear resistance.

[0215] (2) Alloy testing

[0216] The microstructure of the new 28MnB5-M bars was observed using a FEI Nova Nano 450 field emission scanning electron microscope and an optical microscope, as shown in Figure 14. It can be seen that the structure of the 28MnB5-M bars is mainly composed of fine and evenly distributed lath martensite with an average length of about 4.3 μm.

[0217] Under room temperature conditions, the wear loss of the new 28MnB5-M grating was 1.2 mg when tested using an MFT-R4000 high-speed reciprocating friction and wear tester.

[0218] A comparison of the mechanical performance parameters of the new 28MnB5-M bars of this embodiment and existing bars is shown in Figure 15. It can be seen that the yield strength of the new 28MnB5-M bars of this embodiment is 1407 MPa and the tensile strength is 1691 MPa. The impact energy absorbed by the new 28MnB5-M bars is 58.0 J. Combined with the tensile strength data analysis, it can be seen that the new 28MnB5-M bars achieve an excellent balance of strength and toughness. In addition, compared with existing bars, the new 28MnB5-M bars of this embodiment not only have significantly higher yield strength, tensile strength, and toughness, but also have reduced operating resistance during operation.

[0219] The above tests and characterizations demonstrate that the new 28MnB5-M bar components of this embodiment exhibit excellent strength-toughness matching. Furthermore, the new 28MnB5-M bars, after optimizing the curved design parameters, also exhibit low resistance, potentially finding significant applications in agricultural machinery and advanced industry.

[0220] Example 6:

[0221] The steps include:

[0222] (1) Design and manufacture of gratings, including:

[0223] Step X1: Optimize the bar surface using the horizontal straight line design method. To improve the plow's ability to turn over the soil, reduce friction between the bars and the soil, and reduce plow wear, this embodiment calculates the key parameters of the plow bar surface using equations 13-15. The plow width b is 700 mm; the plow blade installation angle ε is 30°; the guide curve buckle angle Δ is 1 / 2. ε The value is 11°, C1 is a constant, and the value is 1.8. According to formulas 13-15, the value of the guide curve opening l is 458mm, the value of the guide curve height h is 870mm, and the value of the end point tangent angle ω is 109°. l=C1b(cosΔε-sinε) (21)

[0224] Step X2: Use UG software to create a 3D model of the plow body. First, select a reference plane and sketch the plow blade and guide curves. Then, using the bar surface parameters from Step X1 and the line number and corresponding line angle calculation formula in Equation 24, draw horizontal straight lines. Finally, draw the front view of the plow body curve and project it to form a closed spatial curve. Then, use the Crop command to crop the plow body surface. Then, use the Extrude command to convert the plow body surface into a 3D solid shape and export the .stl model file.

[0225] Where: n is the number of the element line; θ is the element line angle; θ m and θ n are the element angles when the element number is m and n respectively; θ0 is the initial element angle, which is generally 36°~45°; θ max and θ min The maximum and minimum element line angles respectively; Δ z is the distance between element lines;

[0226] Step X3: ANSYS simulation preparation. Set soil material property parameters: soil density is 1.78×103kg / m 3 , elastic modulus is 4.5×107Pa, Poisson's ratio is 0.35, yield stress is 8.5×105Pa, tangent modulus is 1.2×106Pa, failure strain is 0.8, strain rate is 6%; set the material characteristic parameters of the flip plow fence: density is 7.81×10-6kg / mm 3 , elastic modulus is 2.4×105N / mm 2, Poisson's ratio is 0.4; the contact mode between the plow surface and the soil is set to automatic contact by surface erosion.

[0227] Step X4: Simulation. Import the .stl model file from Step X2 into the ANSYS simulation environment built in Step X3. Set the plow component speed to 0.38 m / s and the forward direction to the positive X-axis. Enter the simulation settings, set the time step and simulation time to 10 seconds. Start the simulation. After the simulation is complete, the average resistance value of the plow component is 4.90 kN.

[0228] Step X5: Preparation of a new 28MnB5-M steel. Based on the existing 28MnB5 steel composition, 0.11% Nb, 0.10% Al, and 0.2% Cu (see Table 4) were added by mass. The alloy was melted in a vacuum induction furnace, cast into a 200 kg ingot, and then forged into a 500 mm × 1000 mm × 50 mm hot-rolled billet. The billet was heated to 1200°C and held at that temperature for 2.0 hours. After removal from the furnace, it was rolled in three passes, with a final rolling temperature of 920°C, resulting in a 12 mm thick plate. The finished plate was water-cooled to the set coiling temperature of 600°C, then placed in a heating furnace, held at that temperature for 30 minutes, and then cooled. Finally, the hot-rolled plate was pickled to remove surface scale.

[0229] Table 8 Comparison of chemical composition of new 28MnB5-M steel and existing 28MnB5 steel (mass fraction, %)

[0230] Step X6: Machining the Bar Blanks: Use oxyacetylene cutting to cut the 28MnB5-M hot-rolled plate from Step X5 into bar blanks. Use a milling machine to fine-machine the bar shape, and use a drilling machine to machine the countersunk square holes for the bars.

[0231] Step X7: Hot forming - normalizing - quenching - tempering treatment of the bars. Heat the bar blank in step X6 to 960°C and keep it warm for 1.2 hours; after the insulation is completed, transfer the bar blank into a stamping die to form it into the three-dimensional solid shape required in step X2, and after the molding is completed, place it in the air to cool to room temperature; heat the bar blank to 920°C again, keep it warm for 0.7 hours, and then immerse it in water to quench it to room temperature; further transfer the quenched bar blank into a tempering furnace with a temperature of 200°C and keep it warm for 2.4 hours, and after the insulation is completed, take it out of the furnace and air cool it. Then perform shot peening and plastic spraying to obtain a high-speed flip plow bar component with low running resistance, high strength, high toughness and high wear resistance.

[0232] (2) Alloy testing

[0233] The microstructure of the new 28MnB5-M bars was observed using a FEI Nova Nano 450 field emission scanning electron microscope and an optical microscope, as shown in Figure 16. It can be seen that the structure of the 28MnB5-M bars is mainly composed of fine and evenly distributed lath martensite with an average length of about 4.5 μm.

[0234] Under room temperature conditions, the wear loss of the new 28MnB5-M grating was 1.6 mg when tested using an MFT-R4000 high-speed reciprocating friction and wear tester.

[0235] A comparison of the mechanical performance parameters of the new 28MnB5-M bars of this embodiment and existing bars is shown in Figure 17. It can be seen that the yield strength of the new 28MnB5-M bars of this embodiment is 1317 MPa and the tensile strength is 1632 MPa. The impact energy absorbed by the new 28MnB5-M bars is 57.0 J. Combined with the tensile strength data analysis, it can be seen that the new 28MnB5-M bars achieve an excellent balance of strength and toughness. In addition, compared with existing bars, the new 28MnB5-M bars of this embodiment not only have significantly higher yield strength, tensile strength, and toughness, but also have reduced operating resistance during operation.

[0236] The above tests and characterizations demonstrate that the new 28MnB5-M bar components of this embodiment exhibit excellent strength-toughness matching. Furthermore, the new 28MnB5-M bars, after optimizing the curved design parameters, also exhibit low resistance, potentially finding significant applications in agricultural machinery and advanced industry.

Claims

1. A method for manufacturing a tip of a reversible plow with low resistance and strong inner and outer properties, characterized in that include: Step S5: preparing a new 34MnCrB5-M steel, comprising: On the basis of the existing 34MnCrB5 steel composition, 0.1-0.3% Nb and 0.1-0.3% V elements are added to form a new 34MnCrB5-M steel with a new composition. The alloy is melted in a medium frequency induction melting furnace and cast into a size of ingots; The ingot is heated to 920℃-960℃ and kept warm for 1.0h-1.2h. After being taken out of the furnace, it is subjected to primary rolling and secondary finishing rolling to form a size of 34MnCrB5-M bars; Cut the bar into plow point blanks with a length of 340mm-360mm; Step S6: Die forging and annealing of the plow tip blank, including: The plow tip blank in step S5 is placed in a heating furnace and heated to 900° C.-950° C., kept at this temperature for 1 hour-2 hours, then taken out of the furnace and transferred to a die forging machine. After die forging is completed, the plow tip blank is cooled in air to room temperature to become a die-forged plow tip blank; The die-forged plow tip blank is transferred to an annealing furnace and heated to 600-650°C, kept at this temperature for 1-2 hours, and then cooled to room temperature. Build-up a carbide layer on the back of the tip of the plow point blank; Step S7: machining the plow tip, including: performing fine machining of the plow tip using a CNC machine tool according to the 3D model data of the plow tip component and the requirements of the drawing, wherein the 3D model data is determined by the following operations: Determine the basic parameters, including establishing the plow blade angle λ0 and the soil internal friction angle φ t The relationship is: The relationship between the angle η between the soil trace line and the plow blade, the plow face angle ε, and the soil lifting angle θ is further established as follows: tanη=tanθcosε (2) Establish a 3D model, including: based on the determined plow blade angle λ0, plow face angle ε, soil trace line and plow blade angle η and soil starting angle θ parameters, use the curve construction command in UG software to generate the main surface, and then perform surface trimming, connection, smoothing, editing, etc. to complete the overall construction, and export the .stl model file. Step S8: carburizing-quenching-tempering treatment of the plow tip, including: The plow tip in step S7 is placed in a gas carburizing furnace, and the carburizing temperature is set to 910℃-930℃, time is 9h-10h, carbon potential is 1.0%-1.2%; After carburizing is completed, the plow tip is transferred to quenching oil at a temperature of 45℃-55℃ for quenching; After quenching, transfer the plow tip to a tempering furnace at 180-200°C for 1.8-2.0 hours, then air cool to room temperature. Shot blasting and plastic spraying are performed.

2. The method for manufacturing a reversible plow tip with low resistance and strong inner and outer properties according to claim 1, characterized in that: The composition of existing 34MnCrB5 steel and the composition of new 34MnCrB5-M steel are: The unit is mass fraction %.

3. The method for manufacturing a reversible plow tip with low resistance and strong inner and outer properties according to claim 1 is characterized by: Soil internal friction angle φ t Less than 4°, the plow blade angle λ0 ranges from 40° to 45°.

4. The method for modeling and manufacturing a reversible plow tip with low resistance and strong inner and outer properties according to claim 1, characterized in that: The angle η between the soil trace line and the plow blade is set to 16°-24°, and the plow face angle ε is set to 30°-40°, so the value range of the soil starting angle θ is 18°-30°.

5. The method for manufacturing a reversible plow tip with low resistance and strong inner and outer properties according to claim 1, characterized in that Further including: The preliminary preparation for EDEM discrete element simulation includes setting the plow body material properties to: The density of the plow body material is 7800kg / m 3 , the shear modulus is 7.0×10 10 Pa, Poisson's ratio is 0.3; Set soil properties: soil density is 2600kg / m 3 , the shear modulus is 2.5×10 7 Pa, Poisson's ratio is 0.5, and the soil particle radius is 2 mm; Set the interaction parameters between soil particles and the plow body's ploughing parts: the static friction factor between soil particles is 0.40, the kinetic friction factor between soil particles is 0.32, the collision recovery coefficient between soil particles is 0.11, the static friction factor between soil particles and the plow body is 0.30, the kinetic friction factor between soil particles and the plow body is 0.22, and the collision recovery coefficient between soil particles and the plow body is 0.18; Perform simulations, including: Import the .stl model file in step S2 into the EDEM software and set the plow body parts to The travel speed is 3.6-3.8m / s, and the forward direction is the X-axis direction; Enter the simulation settings, set the time step and simulation time to 10s, and set the Cell-Size to 2.5Rmin; Start the simulation and obtain the average resistance value of the plow body components through simulation.

6. The method for manufacturing a reversible plow tip with low resistance and strong inner and outer properties according to claim 5, characterized in that: Set the soil internal friction angle φ t Less than 4°, the plow blade angle λ0 ranges from 40° to 45°.

7. The method for manufacturing a reversible plow tip with low resistance and strong inner and outer properties according to claim 1, characterized in that: The angle η between the soil trace line and the plow blade is generally set to 16°-24°, the plow face angle ε is generally set to 30°-40°, and the soil starting angle θ ranges from 18° to 30°.

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