Wear-resistant steel and production method thereof

Abstract

The invention provides wear-resistant steel and a production method thereof, and the wear-resistant steel comprises the following chemical components in percentage by mass: 0.20%-0.55% of C, 0.7%-1.8% of Si, 0.8%-1.7% of Mn, 1.0%-1.2% of Cr, 0.4%-0.8% of Cu, 1.2%-1.5% of Ni, 0.010%-0.05% of Al, less than or equal to 0.01% of P, less than or equal to 0.01% of S, less than or equal to 0.005% of N, 0.01%-0.05% of Nb, 0.08%-0.25% of V and the balance of Fe and inevitable impurities. According to the wear-resistant steel, the content of all the elements is finely regulated and controlled, the wear resistance is improved, meanwhile, the hardenability of the steel is improved, and meanwhile, the mechanical property of the steel is optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of heat treatment technology, and specifically relates to wear-resistant steel and a production method thereof. Background Art

[0002] At present, the heat treatment process of wear-resistant steel is mainly divided into hot rolling online quenching + ultra-fast cooling mode (mostly used for thin plates 4-6mm) and offline heat treatment quenching + low-temperature tempering mode. Among them, the hot rolling online quenching + ultra-fast cooling mode has poor quenching temperature control accuracy, inconsistent ultra-fast cooling up and down, uncontrolled plate shape, and poor steel plate performance stability; while the steel plates produced by the offline heat treatment quenching + low-temperature tempering mode have good performance stability, but are limited by high production costs and lengthy production lines, which seriously delay the production rhythm of wear-resistant steel, and the offline heat treatment quenching + low-temperature tempering mode is difficult to achieve universal application.

[0003] Based on this, it is necessary to provide a wear-resistant steel and a production method thereof to alleviate or solve the above problems. Summary of the invention

[0004] The invention aims to solve the technical problem that the existing wear-resistant steel heat treatment process in the above-mentioned common technology is difficult to reduce costs and increase efficiency while taking into account the excellent performance stability of the steel plate. The present invention provides a wear-resistant steel, whose chemical composition, measured by mass fraction, includes: C 0.20%-0.55%, Si 0.7%-1.8%, Mn 0.8%-1.7%, Cr 1.0%-1.2%, Cu 0.4%-0.8%, Ni 1.2%-1.5%, Al 0.010%-0.05%, P≤0.01%, S≤0.01%, N≤0.005%, Nb0.01%-0.05%, V0.08%-0.25%, and the rest is Fe and unavoidable impurities.

[0005] The present invention provides a method for producing wear-resistant steel, comprising the steps of:

[0006] The slab is heated, and then subjected to a rolling process and a quenching process in sequence to obtain a wear-resistant steel; the chemical composition of the wear-resistant steel includes, by mass fraction, C 0.20% to 0.55%, Si 0.7% to 1.8%, Mn 0.8% to 1.7%, Cr 1.0% to 1.2%, Cu 0.4% to 0.8%, Ni 1.2% to 1.5%, Al 0.010% to 0.05%, P ≤ 0.01%, S ≤ 0.01%, N ≤ 0.005%, Nb 0.01% to 0.05%, V 0.08% to 0.25%, and the rest is Fe and unavoidable impurities;

[0007] The quenching process is controlled to meet the following conditions: the average surface cooling rate of the steel plate before 400°C is 50-53°C·s -1, the average cooling rate at one quarter of the thickness of the steel plate before 400℃ is 27-30℃·s -1 , the average cooling rate at the center of the steel plate before 400℃ is 25-28℃·s -1 .

[0008] Furthermore, the rolling process includes rough rolling and finish rolling, wherein the rough rolling has 5 to 7 passes and the finish rolling inlet temperature is 1150-1050°C.

[0009] Furthermore, the rolling process also includes coiling, and the coiling temperature is 550-600°C 。

[0010] Furthermore, after the quenching process is completed, the temperature of the surface of the wear-resistant steel is 280-310°C.

[0011] Further, the controlling the quenching process includes:

[0012] The quenching process includes heating up the quenching furnace and cooling down the quenching machine; the oxygen content in the quenching furnace is controlled to be less than 800ppm, the heat treatment quenching heating temperature is 850-920℃, the holding time is 15-20min, and the furnace pressure of the quenching furnace is 20-30Pa.

[0013] Furthermore, the quenching machine is used to perform self-tempering treatment on the wear-resistant steel after the quenching process.

[0014] Furthermore, the high pressure of the quenching machine is controlled to be 0.7-1.0 MPa, and the water volume in the high pressure mode is 800-2200m 3 / h; the low pressure of the quenching machine is 0.4-0.6MPa, and the water volume in low pressure mode is 2200-2600m 3 / h.

[0015] Furthermore, in the step of heating the slab and sequentially undergoing a rolling process and a quenching process to obtain wear-resistant steel, the steel plate after the rolling process and before the quenching process is shot blasted, the shot blasting speed is 3-6m / min, the shot blasting current is 38-42A, the shot blasting shot is 0.3-0.8mm particle size shot, and the quantity ratio of the shot with a particle size of 0.6-0.8mm, the shot with a particle size of 0.4-0.5mm, and the shot with a particle size of 0.3mm is 2:1:1.

[0016] Furthermore, the furnace temperature of the slab after heating is 1210-1250°C.

[0017] Compared with the prior art, the present invention has at least the following advantages:

[0018] The present invention controls the chemical composition of the wear-resistant steel as follows: calculated by mass fraction, the steel comprises C 0.20%-0.55%, Si 0.7%-1.8%, Mn 0.8%-1.7%, Cr 1.0%-1.2%, Cu 0.4%-0.8%, Ni 1.2%-1.5%, Al 0.010%-0.05%, P≤0.01%, S≤0.01%, N≤0.005%, Nb 0.01%-0.05%, V 0.08%-0.25%, and the remainder is Fe and unavoidable impurities.

[0019] The present invention controls the mass fraction of carbon element to 0.20% to 0.55%. In comparison, the carbon content of common wear-resistant steel is generally between 0.8% and 1.1%. By controlling the carbon content, the toughness and welding performance of the steel can be improved while ensuring a certain hardness and strength.

[0020] The present invention controls the silicon content within the range of 0.7% to 1.8%, which can further optimize the mechanical properties of the steel and improve the corrosion resistance of the steel.

[0021] The present invention controls the manganese content within the range of 0.8% to 1.7%. Through fine regulation of the manganese content, the strength and toughness of the steel can be improved, while the hardenability of the steel can be increased, thereby achieving significant improvement in the heat treatment performance of the steel.

[0022] The present invention controls the chromium content between 1.0% and 1.2%. In comparison, the chromium content in ordinary wear-resistant steel is often between 11% and 30%. The wear-resistant steel of the present invention can reduce the cost and improve the toughness of the steel while ensuring wear resistance by reducing the chromium content.

[0023] The present invention controls the contents of copper, nickel and aluminum to 0.4% to 0.8%, 1.2% to 1.5% and 0.010% to 0.05% respectively. The addition of appropriate amounts of the above elements can further enhance the corrosion resistance and strength of the steel.

[0024] The invention controls the contents of phosphorus, sulfur and nitrogen within the range of P≤0.01%, S≤0.01% and N≤0.005% respectively. The wear-resistant steel of the invention can significantly improve the toughness and welding performance of the steel by strictly controlling the contents of these elements.

[0025] The present invention controls the contents of niobium and vanadium to 0.01% to 0.05% and 0.08% to 0.25% respectively. Niobium and vanadium are microalloying elements in steel. The addition of appropriate amounts of niobium and vanadium can increase the strength and toughness of steel and improve the hardenability and self-tempering stability of steel.

[0026] In summary, the wear-resistant steel of the present invention improves the wear resistance and hardenability of the steel by finely controlling the content of each element, and optimizes the mechanical properties of the steel. These advantages make the wear-resistant steel of the present invention have a wider application prospect in the fields of mining machinery, engineering machinery, coal machinery, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 This is a curve diagram of the temperature change of different parts of the steel plate over time during the quenching process in Example 1 of the present invention.

[0029] Figure 2 Schematic diagram of the change in cooling rate over time at different parts of a steel plate during the quenching process in Example 1 of the present invention.

[0030] Figure 3 This is the metallographic structure diagram of the wear-resistant steel NM450 steel plate 1 prepared in Example 1 of the present invention.

[0031] Figure 4 This is the metallographic structure diagram of the wear-resistant steel NM450 steel plate 2 prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0035] In order to solve the technical problems faced by the above-mentioned conventional technologies, the present invention provides a wear-resistant steel, whose chemical composition, measured by mass fraction, includes: C 0.20%-0.55%, Si 0.7%-1.8%, Mn 0.8%-1.7%, Cr 1.0%-1.2%, Cu 0.4%-0.8%, Ni 1.2%-1.5%, Al 0.010%-0.05%, P≤0.01%, S≤0.01%, N≤0.005%, Nb 0.01%-0.05%, V 0.08%-0.25%, and the rest is Fe and unavoidable impurities.

[0036] The present invention controls the mass fraction of carbon element to 0.20% to 0.55%. In comparison, the carbon content of common wear-resistant steel is generally between 0.8% and 1.1%. By controlling the carbon content, the toughness and welding performance of the steel can be improved while ensuring a certain hardness and strength.

[0037] The present invention controls the silicon content within the range of 0.7% to 1.8%, which can further optimize the mechanical properties of the steel and improve the corrosion resistance of the steel.

[0038] The present invention controls the manganese content within the range of 0.8% to 1.7%. Through fine regulation of the manganese content, the strength and toughness of the steel can be improved, while the hardenability of the steel can be increased, thereby achieving significant improvement in the heat treatment performance of the steel.

[0039] The present invention controls the chromium content between 1.0% and 1.2%. In comparison, the chromium content in ordinary wear-resistant steel is often between 11% and 30%. The wear-resistant steel of the present invention can reduce the cost and improve the toughness of the steel while ensuring wear resistance by reducing the chromium content.

[0040] The present invention controls the contents of copper, nickel and aluminum to 0.4% to 0.8%, 1.2% to 1.5% and 0.010% to 0.05% respectively. The addition of appropriate amounts of the above elements can further enhance the corrosion resistance and strength of the steel.

[0041] The invention controls the contents of phosphorus, sulfur and nitrogen within the range of P≤0.01%, S≤0.01% and N≤0.005% respectively. The wear-resistant steel of the invention can significantly improve the toughness and welding performance of the steel by strictly controlling the contents of these elements.

[0042] The present invention controls the contents of niobium and vanadium to 0.01% to 0.05% and 0.08% to 0.25% respectively. Niobium and vanadium are microalloying elements in steel. The addition of appropriate amounts of niobium and vanadium can increase the strength and toughness of steel and improve the hardenability and tempering stability of steel.

[0043] In summary, the wear-resistant steel of the present invention improves the wear resistance and hardenability of the steel by finely controlling the content of each element, and optimizes the mechanical properties of the steel. These advantages make the wear-resistant steel of the present invention have a wider application prospect in the fields of mining machinery, engineering machinery, coal machinery, etc.

[0044] The present invention provides a method for producing wear-resistant steel, comprising the steps of:

[0045] The slab is heated and successively subjected to a rolling process and a quenching process to obtain wear-resistant steel.

[0046] The temperature of the slab after heating can be 1210-1250°C.

[0047] The rolling process may include rough rolling and finish rolling, wherein the rough rolling has 5 to 7 rolling passes and the finish rolling inlet temperature is 1150-1050°C.

[0048] In some embodiments, the inlet temperature of the rough rolling may be 1050° C. to 1100° C., and the number of passes of the finishing rolling may be 5 to 7 times.

[0049] In some specific embodiments, the rolling process may include the steps of: slab heating → high-pressure water roughing descaling → rough rolling → head and tail cutting → high-pressure water fine descaling → fine rolling → layer cooling → coiling → packaging.

[0050] For example, the coiling temperature may be 550-600°C. 。

[0051] The steel plate after the rolling process and before the quenching process is shot blasted, wherein the shot blasting speed is 3-6 m / min, the shot blasting current is 38-42 A, the shot blasting shot material is 0.3-0.8 mm particle size shot material, and the ratio of particle size 0.6-0.8 to particle size 0.4-0.5 to particle size 0.3 is 2:1:1.

[0052] The heat treatment process in the present invention is a quenching process + self-tempering.

[0053] Among them, the temperature-controlled self-tempering process mainly includes the steps of heating up the quenching furnace and cooling down the quenching machine.

[0054] During the heating process of the quenching furnace, the temperature inside the quenching furnace can be set to 850-920°C, and the insulation time can be set to 15-20 minutes.

[0055] In the quenching process, the average cooling rate of the steel plate surface before 400℃ can be controlled to be 50-53℃·s during the temperature drop of the quenching machine. -1 , the average cooling rate at one quarter of the thickness of the steel plate before 400℃ is 27-30℃·s -1 , the average cooling rate at the center of the steel plate before 400℃ is 25-28℃·s -1 .

[0056] For example, the average cooling rate of the steel plate surface before 400°C can be controlled to be 50-52°C·s -1 , the average cooling rate at one quarter of the thickness of the steel plate before 400℃ is 28~30℃·s -1 The average cooling rate at the center of the steel plate before 400°C is 27-28°C·s -1 .

[0057] In some embodiments, during the quenching process, the temperature variation curves of the center of the steel plate, the quarter thickness of the steel plate, and the surface of the steel plate can be as follows: Figure 1 shown.

[0058] The quenching process mainly uses quenching furnaces and quenching machines. Quenching furnaces are equipment for heating workpieces before quenching, mainly including continuous atmosphere protection quenching furnaces, mesh belt quenching furnaces, vertical quenching furnaces, horizontal air quenching furnaces, vacuum quenching furnaces, etc.

[0059] The quenching machine is a device that uses high-frequency current to locally heat and cool the workpiece, and is mainly used to obtain a surface hardened layer.

[0060] In the quenching process, the quenching furnace and the quenching machine are used together. First, the workpiece is heated to a temperature above the critical point in the quenching furnace and maintained for a period of time to ensure that the internal structure of the workpiece reaches the conditions required for quenching. Then, the workpiece is quickly taken out of the quenching furnace and placed in the quenching machine for local induction heating and cooling treatment to obtain the required surface hardening layer. This combination of use can give full play to the advantages of both and improve the efficiency and quality of the quenching process.

[0061] In the quenching process of the present invention, the parameters can be controlled as follows: the oxygen content in the quenching furnace is less than 800ppm, the temperature in the furnace is 850-920°C, the holding time is 15-20min, and the furnace pressure of the quenching furnace is 20-30Pa.

[0062] The high pressure of the quenching machine is 0.7-1.0MPa, and the water volume in high pressure mode is 800-2200m 3 / h; the low pressure of the quenching machine is 0.4-0.6MPa, and the water volume in low pressure mode is 2200-2600m 3 / h.

[0063] Exemplarily, the water temperature may be 15-25°C.

[0064] In some embodiments, the temperature of the wear-resistant steel surface after the quenching process is completed may be 280-310°C.

[0065] In other embodiments, the wear-resistant steel after the quenching process may be subjected to a self-tempering treatment.

[0066] In comparison, the heat treatment process in commonly used technologies is mainly divided into hot rolling online quenching + ultra-fast cooling mode (mostly used for thin plates 4-6mm) and offline heat treatment quenching + low-temperature tempering mode. Among them, the hot rolling online quenching + ultra-fast cooling mode has poor performance stability of the steel plate, which will not be repeated here; while the steel plate produced by the offline heat treatment quenching + low-temperature tempering mode has good performance stability, but is limited by the high production cost and lengthy production line, which seriously delays the production rhythm of wear-resistant steel, and the offline heat treatment quenching + low-temperature tempering mode is difficult to achieve universal application.

[0067] Specifically, the offline heat treatment quenching + low temperature tempering in the commonly used technology includes the following steps:

[0068] Quenching

[0069] Heating: Place the steel plate in a heat treatment furnace and heat it to above the critical temperature, which is usually 30 to 50°C above the Ac3 (or Acm) point of the steel. The heating time depends on the size of the steel plate and the heating capacity of the heat treatment furnace.

[0070] Insulation: Keep the temperature above the critical temperature for a period of time to ensure that the internal structure of the steel plate is fully austenitized. The insulation time also depends on the size of the steel plate and the heating conditions. The steel plate can then be taken out and left for a period of time until the internal temperature distribution is relatively uniform.

[0071] Quenching: The heated and held steel plate is rapidly cooled to obtain a martensitic structure. The quenching medium is usually water, brine or oil, depending on the composition of the steel plate and the required properties. The quenching time is very short, usually ranging from a few seconds to a few minutes.

[0072] Low temperature tempering

[0073] Heating: The quenched steel plate is put back into the heat treatment furnace and heated to the low temperature tempering temperature range (usually between 150 and 250°C). The heating time depends on the size of the steel plate and the heating capacity of the heat treatment furnace.

[0074] Insulation: Keep the steel plate at low tempering temperature for a period of time to ensure that the internal structure of the steel plate is fully transformed into tempered martensite. The insulation time is usually 1 to 2 hours, but the specific time depends on the type of material, the size of the workpiece, and the performance requirements to be achieved after tempering.

[0075] Cooling: After tempering, the workpiece is usually cooled in air to room temperature.

[0076] In common technologies, whether quenching or low-temperature tempering, the steel plate needs to be heated to a higher temperature. This consumes a lot of energy, such as electricity or fuel. Offline heat treatment requires special heat treatment furnaces, quenching equipment, and testing equipment, etc. The purchase and maintenance costs of these equipment are high, and the low-temperature tempering process requires precise control of parameters such as heating temperature, holding time, and cooling rate to ensure that the steel plate obtains the required structure and performance.

[0077] In comparison, the heat treatment process in the wear-resistant steel production method provided by the present invention is a temperature-controlled quenching + self-tempering mode, which can simplify lengthy processes, reduce costs and energy consumption while taking into account the performance stability of the steel plate and optimizing the mechanical properties of the steel plate. It is economically and environmentally friendly and has a wide range of applications.

[0078] In order to facilitate those skilled in the art to further understand the present invention, examples are given below:

[0079] Example 1

[0080] The slab is heated, and then subjected to a rolling process and a quenching process in sequence to obtain a wear-resistant steel NM450 steel plate 1.

[0081] In terms of mass fraction, the chemical composition of the wear-resistant steel NM450 steel plate 1 includes: C 0.45%, Si 1.2%, Mn 1.2%, Cr 1.1%, Cu 0.6%, Ni 1.5%, Al 0.05%, P ≤ 0.01%, S ≤ 0.01%, N ≤ 0.005%, Nb 0.05%, and V 0.25%.

[0082] In the rolling process, the rough rolling passes are 5 to 7 times, the finishing rolling inlet temperature is 1150-1050°C, and the coiling temperature is 550-600°C.

[0083] The heat treatment process of wear-resistant steel NM450 steel plate 1 is temperature-controlled quenching + self-tempering, wherein the temperature-controlled quenching includes the heating process of the quenching furnace and the temperature drop process of the quenching machine:

[0084] The steel plate is placed in a quenching furnace with a temperature of 850-920°C and a holding time of 15-20 minutes. The steel plate is then quenched using a quenching machine. The average surface cooling rate of the steel plate before 400°C is controlled to be 51.34°C·s -1 , the average cooling rate at one quarter of the thickness of the steel plate before 400℃ is 29.92℃·s -1 The average cooling rate at the center of the steel plate before 400℃ is 27.62℃·s -1 , the temperature of the wear-resistant steel after the quenching process is 300°C. Among them, the cooling rate in the steel plate interval quenching machine is as follows Figure 1 , Figure 2 shown.

[0085] After the quenching process, the steel plate is self-tempered to obtain NM450 steel plate 1.

[0086] Comparative Example 1

[0087] The other steps in Example 1 remain unchanged, and the heat treatment process of the wear-resistant steel NM450 steel plate 2 is quenching + low-temperature offline tempering.

[0088] The steel plate is placed in a quenching furnace with a temperature of 850-920°C and a holding time of 15-20 minutes. The heated and held steel plate is hardened by a quenching machine at a temperature of 45-50°C·s -1 The cooling rate cools rapidly.

[0089] The steel plate is then placed in the tempering furnace again, heated to 150-250°C and kept warm for 0.5-1h, and then cooled to room temperature in air to obtain NM450 steel plate 2.

[0090] Analysis example 1

[0091] 1. The NM450 steel plate 1 prepared in Example 1 and the NM450 steel plate 2 prepared in Comparative Example 1 were analyzed as follows:

[0092] Table 1: Mechanical properties comparison of NM450 steel plate 1 and NM450 steel plate 2

[0093] serial number Yield strength / MPa Tensile strength / MPa Elongation / % Steel Plate 1 1251 1528 14.6 Steel Plate 2 1275 1534 13.6

[0094] It can be seen that the performance of the steel plates obtained by the two methods can meet the requirements, and the steel plate obtained by the method of the present invention has better elongation than the conventional quenching and tempering process steel plate while meeting the strength and hardness. The improvement of elongation means that the steel plate has better forming performance, which is conducive to subsequent manufacturing and processing.

[0095] 2. Analyze the energy consumption of Example 1 and Comparative Example 1.

[0096] Table 2: Energy consumption diagram of Example 1 and Comparative Example 1

[0097]

[0098]

[0099] It can be seen that Option 1 has lower production costs and is more environmentally friendly than Option 2.

[0100] 3. Analyze the metallographic structures of NM450 steel plate 1 and NM450 steel plate 2. Figure 3 , Figure 4 shown.

[0101] By comparison, it can be found that the martensitic lath morphology in the microstructure of the steel plate prepared by the method of the present invention is clearly visible, and a small amount of carbide precipitation exists between the laths, while the martensitic laths of the steel plate prepared by the traditional quenching and tempering process are partially recovered, and the number of precipitated carbides is significantly larger, which is not conducive to the elongation performance of the steel plate.

[0102] The above technical solutions of the present invention are only preferred embodiments of the present invention, and the patent scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A wear-resistant steel, characterized in that: Calculated by mass fraction, its chemical composition includes: C 0.20%~0.55%, Si0.7%~1.8%, Mn 0.8%~1.7%, Cr 1.0%~1.2%, Cu 0.4%~0.8%, Ni1.2%~1.5%, Al0.010%~0.05%, P≤0.01%, S≤0.01%, N≤0.005%, Nb0.01%~0.05%, V0.08%~0.25%, and the rest is Fe and unavoidable impurities.

2. A method for producing wear-resistant steel, characterized in that: Includes steps: The slab is heated, and then subjected to a rolling process and a quenching process in sequence to obtain a wear-resistant steel; the chemical composition of the wear-resistant steel includes, by mass fraction, C 0.20% to 0.55%, Si 0.7% to 1.8%, Mn 0.8% to 1.7%, Cr 1.0% to 1.2%, Cu 0.4% to 0.8%, Ni 1.2% to 1.5%, Al 0.010% to 0.05%, P ≤ 0.01%, S ≤ 0.01%, N ≤ 0.005%, Nb 0.01% to 0.05%, V 0.08% to 0.25%, and the rest is Fe and unavoidable impurities The quenching process is controlled to meet the following conditions: the average surface cooling rate of the steel plate before 400°C is 50-53°C·s -1 , the average cooling rate at one quarter of the thickness of the steel plate before 400℃ is 27-30℃·s -1 , the average cooling rate at the center of the steel plate before 400℃ is 25-28℃·s -1 .

3. The method for producing wear-resistant steel according to claim 2, characterized in that: The rolling process includes rough rolling and finish rolling, wherein the rough rolling has 5 to 7 passes and the finish rolling inlet temperature is 1150-1050°C.

4. The method for producing wear-resistant steel according to claim 3, characterized in that: The rolling process also includes coiling, and the coiling temperature is 550-600°C 。 5. The method for producing wear-resistant steel according to claim 2, characterized in that: After the quenching process is completed, the temperature of the wear-resistant steel surface is 280-310°C.

6. The method for producing wear-resistant steel according to claim 5, characterized in that: The controlling the quenching process comprises: The quenching process includes heating up the quenching furnace and cooling down the quenching machine; the oxygen content in the quenching furnace is controlled to be less than 800ppm, the heat treatment quenching heating temperature is 850-920℃, the holding time is 15-20min, and the furnace pressure of the quenching furnace is 20-30Pa.

7. The method for producing wear-resistant steel according to claim 6, characterized in that: The quenching machine is used to perform self-tempering treatment on the wear-resistant steel after the quenching process.

8. The method for producing wear-resistant steel according to claim 7, characterized in that: The high pressure of the quenching machine is controlled to be 0.7-1.0 MPa, and the water volume in the high pressure mode is 800-2200m 3 / h; the low pressure of the quenching machine is 0.4-0.6MPa, and the water volume in low pressure mode is 2200-2600m 3 / h.

9. The method for producing wear-resistant steel according to claim 2, characterized in that: In the step of heating the slab and sequentially undergoing a rolling process and a quenching process to obtain wear-resistant steel, the steel plate after the rolling process and before the quenching process is shot blasted, the shot blasting speed is 3-6m / min, the shot blasting current is 38-42A, the shot blasting shot is 0.3-0.8mm particle size shot, and the quantity ratio of the shot with a particle size of 0.6-0.8mm, the shot with a particle size of 0.4-0.5mm, and the shot with a particle size of 0.3mm is 2:1:

1.

10. The method for producing wear-resistant steel according to claim 2, characterized in that: The furnace temperature of the heated slab is 1210-1250°C.

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