Low-cost wear-resistant steel with Brinell hardness of 500 HBW and manufacturing method

Abstract

According to the low-cost wear-resistant steel with the Brinell hardness of 500 HBW grade and the manufacturing method, in the aspect of component design, Mo element is replaced with Nb element, and the content of precious metal elements is reduced so as to reduce the cost; in the aspect of the manufacturing process, the finish rolling temperature is increased, the coiling temperature is increased, and it is guaranteed that the steel has the good forming performance before heat treatment; the heat treatment process of quenching and low-temperature tempering is adopted, so that the steel still has certain forming performance while the mechanical property reaches the standard after heat treatment; according to the wear-resistant steel produced through the method, the cost is reduced, meanwhile, the mechanical property can still reach the Brinell hardness of 500 HBW, and the cost advantage is beneficial to popularization of the high-grade wear-resistant steel in the market; the steel is mainly applied to a special vehicle structure, the weight of a vehicle body of the special vehicle is reduced, the purpose of vehicle body weight reduction is achieved, and the purposes of carbon reduction, energy conservation and emission reduction are further promoted.

Description

Technical Field

[0001] The present invention relates to the field of metallurgy, and in particular to the processing of alloys or nonferrous metals. Background Art

[0002] The high weight of special-purpose vehicles means more fuel consumption, more CO2 emissions and lower load. The key to solving these problems lies in the application of new materials and processes. By reducing weight, vehicles can save 25% to 37% of fuel.

[0003] At present, multi-material body structure design has become a development trend. By optimizing the body structure, it can not only improve vehicle performance but also significantly reduce deadweight. At present, high-strength steel, wear-resistant steel and aluminum have become the main materials, emphasizing the use of appropriate materials in appropriate parts. Among them, wear-resistant steel is mainly used in heavy-duty mining trucks and highway dump truck bodies, semi-trailer beams, booms, etc. Compared with general structural steel, wear-resistant steel is more wear-resistant, has higher strength, and has a thinner and lighter body, such as the high-strength wear-resistant steel disclosed in CN202211448897 and the high-wear-resistant steel for coal mining disclosed in CN202210137163. However, the alloy cost and production process cost are both high, and there is a problem of low elongation after fracture, which limits its application range. Summary of the invention

[0004] In view of this, the present disclosure provides a low-cost wear-resistant steel with a Brinell hardness of 500 HBW and a manufacturing method thereof, which solves the current problems of high manufacturing cost and low elongation after fracture of wear-resistant steel.

[0005] To achieve the above-mentioned object of the invention, in the first aspect, the low-cost Brinell hardness 500 HBW grade wear-resistant steel has the following chemical composition by mass percentage:

[0006] C: 0.18%~0.25%, Si: 0.25%~0.40%, Mn: 1.3%~1.7%, S: ≤0.03%, P: ≤0.03%, Al: 0.015%~0.055%, Nb: 0.015~0.035, Ti: 0.020~0.045%, Cr: 0.3%-0.45%, B: 0.0005~0.0030%, O: ≤0.004%, N: ≤0.006%, the rest are Fe and other unavoidable impurities.

[0007] In the second aspect, the method for manufacturing the low-cost Brinell hardness 500 HBW grade wear-resistant steel in the first aspect comprises a steelmaking process, a hot rolling process and a heat treatment process, wherein the steelmaking process comprises a molten iron pretreatment, a converter process, a refining process and a continuous casting process, and the hot rolling process comprises a rough rolling process, a finishing rolling process, a cooling process and a coiling process, wherein:

[0008] In the finishing process and the coiling process, the finishing outlet temperature is controlled to be 860-900°C, and the finishing rolling is performed to a thickness of 2.0-12.0 mm; the coiling temperature is controlled to be 660-700°C, and the cooling mode adopts an intermittent cooling mode;

[0009] The control parameters of the heat treatment process are: quenching at 880°C to 920°C, heating with the furnace, keeping warm for 5 to 10 minutes, tempering at 200 to 240°C, and keeping warm for 15 to 25 minutes.

[0010] In the present disclosure and possible embodiments, in the rough rolling process, the rough rolling pass adopts a mode of R1 rolling back and forth 3 times and R2 rolling back and forth 3 times, and the thickness of the rough rolling intermediate billet is 30-40 mm;

[0011] The rough rolling and the finish rolling are each subjected to dephosphorization treatment, and the water pressure is 200-250 bar.

[0012] In the present disclosure and possible embodiments, in the hot rolling process, the slab furnace temperature is controlled to be 1200-1280°C, and the furnace time is 150-250min;

[0013] In the cooling process, a slow cooling treatment is performed in a hot zone in a warehouse after the hot rolling.

[0014] In the present disclosure and possible embodiments, during the molten iron pretreatment, the molten iron pretreatment S is controlled to be ≤0.003% and the slag is skimmed off; refined scrap steel is used; and the slag amount of the molten iron entering the converter is ≤20mm.

[0015] In the present disclosure and possible embodiments, in the converter process, the endpoint oxygen is controlled to be 400ppm to 700ppm; repeated blowing is performed, and supplementary blowing is prohibited; the steel tapping time is 4min to 8min; and the ladle slag thickness is ≤70mm.

[0016] In the present disclosure and possible embodiments, in the refining process, LF furnace refining treatment is adopted, and the LF furnace refining treatment process maintains a slightly positive pressure, and the N increase is ≤10ppm; active lime and fluorite are used to make reducing slag, and the argon blowing intensity is controlled to avoid exposure of molten steel; silicon calcium wire is used for calcium treatment.

[0017] In the present disclosure and possible embodiments, in the continuous casting process, the tundish pouring tonnage is used, the tundish superheat control target is ≤25°C, the constant casting speed is ≤1.2m / min, and the crystallizer liquid level fluctuation is ≤±3mm.

[0018] The present invention has the following beneficial effects:

[0019] The low-cost wear-resistant steel with a Brinell hardness of 500 HBW and the manufacturing method of the present invention, in terms of component design, replaces the Mo element with the Nb element, reduces the content of precious metal elements, and has lower cost compared with the national standard; in terms of production, the final rolling temperature and the coiling temperature are increased to ensure that the steel has good forming performance before heat treatment; a heat treatment process of quenching + low-temperature tempering is adopted, so that the mechanical properties of the steel after heat treatment meet the standards while still having certain forming performance, which is beneficial to subsequent forming processing; the low-cost wear-resistant steel with a Brinell hardness of 500 HBW produced by the method of the present invention has excellent cost control and improved elongation after fracture, and the final mechanical properties can reach the Brinell hardness of 500 HBW, and the cost advantage is beneficial to the promotion of high-level wear-resistant steel in the market; the steel is mainly used in the structure of special-purpose vehicles, which is beneficial to the weight reduction of the body of the special-purpose vehicle, achieves the purpose of lightweight body, and further promotes the goals of carbon reduction and energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of a method for manufacturing low-cost 500 HBW grade Brinell hardness wear-resistant steel according to an embodiment of the present disclosure;

[0021] Figure 2 The metallographic structure of the steel strip of Example 1;

[0022] Figure 3 The metallographic structure of the steel strip of Example 2;

[0023] Figure 4 The metallographic structure of the steel strip of Example 3;

[0024] Figure 5 This is the metallographic structure of the steel strip in comparative example 1; DETAILED DESCRIPTION

[0025] The present disclosure is described below based on embodiments, but it is worth noting that the present disclosure is not limited to these embodiments. In the detailed description of the present disclosure below, some specific details are described in detail. However, for the parts that are not described in detail, those skilled in the art can also fully understand the present disclosure. At the same time, unless the context clearly requires, the words "including", "comprising" and the like in the entire specification and claims should be interpreted as including rather than exclusive or exhaustive meanings; that is, the meaning of "including but not limited to".

[0026] The manufacturing method of low-cost Brinell hardness 500 HBW grade wear-resistant steel in each embodiment of the present disclosure is as follows:

[0027] 1. The chemical composition of the wear-resistant steel and the mass percentage of each component are designed to be:

[0028] C: 0.18%~0.25%, Si: 0.25%~0.40%, Mn: 1.3%~1.7%, S: ≤0.03%, P: ≤0.03%, Al: 0.015%~0.055%, Nb: 0.015~0.035, Ti: 0.020~0.045%, Cr: 0.3%-0.45%, B: 0.0005~0.0030%, O: ≤0.004%, N: ≤0.006%, the rest are Fe and other unavoidable impurities.

[0029] In terms of composition design, the disclosed embodiment uses Nb element to replace Mo element compared to the national standard, which has the effect of reducing the content of precious metal elements, thereby lowering the manufacturing cost.

[0030] 2. The manufacturing process of the wear-resistant steel, such as Figure 1 As shown, the specific steps are as follows:

[0031] 1. Steelmaking process:

[0032] (1) Hot metal pretreatment

[0033] In each embodiment of the present disclosure, the molten iron pretreatment S is controlled to be ≤0.003% before entering the furnace, and the slag is removed; refined scrap steel is used; and the slag amount of the molten iron entering the converter is ≤20mm.

[0034] (2) Converter process

[0035] In the converter process of each embodiment of the present disclosure, the endpoint oxygen is controlled to be 400ppm~700ppm; repeated blowing is allowed, and supplementary blowing is prohibited; the steel tapping time is 4min~8min; and the ladle slag thickness is ≤70mm.

[0036] (3) Refining process

[0037] In the refining process of each embodiment of the present disclosure, LF furnace refining treatment is adopted, and the gas content is strictly controlled; the LF treatment process is required to maintain a slightly positive pressure, and the N increase is required to be ≤10ppm; LF uses active lime and fluorite to make a reducing slag with good fluidity, and the argon blowing intensity is strictly controlled to avoid exposure of molten steel as much as possible; silicon calcium wire is used for calcium treatment, and 500 meters of CaSi wire is fed per furnace. The specification of the furnace is 180 tons, so that the inclusions are fully spheroidized.

[0038] (4) Continuous casting process

[0039] In the continuous casting process of each embodiment of the present invention, the tundish is used for pouring, and low tonnage is not allowed; the tundish superheat control target is ≤25°C, and the constant pulling speed is ≤1.2m / min; the crystallizer liquid level fluctuation is ≤±3mm; the ladle casting residue is controlled, and slag is not allowed (remaining steel ≥2t); the opening degree of the rollers in the second cooling zone of the casting machine and the control of the arc accuracy are strengthened, and production is carried out when the casting machine is in good condition, and the casting is put into production with light pressure; the ingots need to be taken off the line for cleaning.

[0040] 2. Hot rolling process:

[0041] (1) Slab and heating area

[0042] In each embodiment of the present disclosure, the slab outlet temperature is controlled to be 1200-1280°C, and the time in the furnace is 150-250 minutes; its purpose and function is to control the furnace atmosphere of the heating furnace, reduce the formation of iron oxide scale of the cast slab, and ensure uniform heating temperature.

[0043] (2) Rough rolling process and finishing rolling process

[0044] In the rough rolling and finishing rolling processes of each embodiment of the present disclosure, the rough rolling pass adopts a 3+3 mode, that is, R1 is rolled back and forth 3 times, R2 is rolled back and forth 3 times, and the thickness of the rough rolling intermediate billet is 30-40 mm; its purpose and function is to do a good job of load distribution of the finishing rolling model and ensure rolling stability.

[0045] The finishing rolling outlet temperature target is controlled at 860-900°C, and the finishing rolling is performed to a thickness of 2.0-12.0 mm.

[0046] Phosphorus removal is performed in each pass of rough rolling and finishing rolling, with a water pressure of 200 to 250 bar.

[0047] (3) Cooling process

[0048] In the cooling process of each embodiment of the present disclosure, the hot zone in the warehouse is slowly cooled after hot rolling. It is required to be away from the warehouse door and surrounded by cooling to avoid direct cold wind. It can be moved after 32 hours.

[0049] (4) Coiling process

[0050] In the coiling process of each embodiment of the present disclosure, the coiling temperature target is controlled to be 660-700° C., and the cooling mode adopts an intermittent cooling method; it is required to ensure the accuracy of the final rolling and coiling temperatures.

[0051] In the rolling aspect of the present disclosure, by adopting processes such as increasing the final rolling temperature and reasonably distributing the rolling force, the coiling temperature is increased to ensure that the steel has good forming properties before heat treatment.

[0052] 3. Heat treatment process:

[0053] In the heat treatment process of each embodiment of the present disclosure, quenching is controlled at 880°C to 920°C, the temperature is raised with the furnace, and the temperature is kept for 5 to 10 minutes, and tempering is carried out at 200 to 240°C and the temperature is kept for 15 to 25 minutes.

[0054] In the heat treatment aspect of the present disclosure, by adopting the heat treatment process of quenching + low temperature tempering, the mechanical properties of the steel material after heat treatment meet the standards while still having certain forming properties, which is beneficial to the subsequent forming processing.

[0055] The following are preferred embodiments of the present invention.

[0056] Example 1

[0057] In this embodiment 1, a production line of Bengang Plate Co., Ltd. is used to produce products with a specification of 4.0mm*1500mm, and to manufacture low-cost wear-resistant steel with a Brinell hardness of 500HBW. The specific manufacturing process is as follows:

[0058] 1. Chemical composition design

[0059] In this embodiment 1, the chemical composition of the wear-resistant steel is as follows in terms of mass percentage:

[0060] C: 0.20%, Si: 0.30%, Mn: 1.5%, P: 0.012%, S: 0.002%, Al: 0.035%, Nb: 0.020%, B: 0.0020%, Ti: 0.035%, Cr: 0.38%, O: 0.0035%, N: 0.0040%, and the balance is Fe and unavoidable impurities.

[0061] 2. Manufacturing process steps

[0062] In this embodiment 1, the manufacturing process and process parameters of the wear-resistant steel are as follows:

[0063] 1. Steelmaking process

[0064] In this embodiment 1, a production route of converter combined blowing, LF refining, and slab continuous casting is adopted. In the continuous casting process, the superheat of the tundish is 21° C. and the constant pulling speed is 1.1 m / min.

[0065] 2. Hot rolling process

[0066] In this embodiment 1, the 2300 production line of Bengang Plate Co., Ltd. is used for rolling, the outlet temperature of the heating furnace is 1262°C, the time in the furnace is 160min, the outlet temperature of rough rolling R1 is 1002°C, the outlet temperature of R2 is 1066°C, and 3 rolling passes are performed for each pass. Dephosphorization is performed in each pass, and the thickness of the intermediate billet is 35mm.

[0067] The inlet temperature of finishing rolling F1 is 1019°C, and the final rolling temperature is 862°C; the finishing rolling is to a thickness of 4mm, and dephosphorization is performed in each pass of rough rolling and finishing rolling, and the water pressure is 230bar.

[0068] After finishing rolling, intermittent cooling mode is adopted and the coiling temperature is 679℃.

[0069] 3. Heat treatment process

[0070] In the heat treatment process of this embodiment 1, the temperature is raised with the furnace, quenched at 920° C., kept warm for 8 minutes, tempered at 200° C., and kept warm for 22 minutes.

[0071] 3. Product organization and performance testing:

[0072] The steel strip produced in Example 1 was subjected to organizational and performance tests, wherein the performance indicators of the tests are shown in Table 1, and the metallographic structure is shown in Table Figure 1 :

[0073] Table 1 Performance index of steel strip in Example 1

[0074]

[0075] Combined with Table 1 above Figure 1 It can be seen that the wear-resistant steel produced in Example 1 has improved elongation after fracture, meeting the requirements of mechanical properties such as strength, plasticity, and toughness, and the metallographic structure is mainly martensite + a small amount of ferrite.

[0076] Example 2

[0077] In this embodiment 2, a production line of Bengang Plate Co., Ltd. is used to manufacture low-cost 500 HBW grade wear-resistant steel with a Brinell hardness of 7.0 mm*1500 mm. The specific manufacturing process is as follows:

[0078] 1. Chemical composition design:

[0079] In this embodiment 2, the chemical composition of the wear-resistant steel is, calculated in the following mass percentages: C: 0.22%, Si: 0.32%, Mn: 1.55%, P: 0.013%, S: 0.002%, Al: 0.041%, Nb: 0.024%, B: 0.0024%, Ti: 0.044%, Cr: 0.39%, O: 0.0030%, N: 0.0043%, and the remainder is Fe and unavoidable impurities.

[0080] 2. Manufacturing process steps

[0081] In this embodiment 2, the manufacturing process and process parameters of the wear-resistant steel are as follows:

[0082] 1. Steelmaking process

[0083] In this embodiment 2, the production route adopted for steelmaking includes converter combined blowing, LF refining and slab continuous casting. During the continuous casting process, the continuous casting superheat is 22° C. and the constant casting speed is 1.0 m / min.

[0084] 2. Hot rolling process

[0085] In this embodiment 2, the 2300 production line is used for rolling, the temperature out of the heating furnace is 1249° C., and the time in the furnace is 200 minutes.

[0086] The outlet temperature of the rough rolling R1 is 1017℃, and the outlet temperature of R2 is 1094℃. Three passes are performed for each rolling, and dephosphorization is performed in each pass. The thickness of the intermediate billet is 38mm.

[0087] The inlet temperature of finishing rolling F1 is 1060℃, the final rolling temperature is 880℃, and the finishing rolling is carried out to a thickness of 7mm; dephosphorization is carried out in each pass of rough rolling and finishing rolling, and the water pressure is 236bar.

[0088] After finishing rolling, intermittent cooling mode is adopted and the coiling temperature is 682℃.

[0089] 3. Heat treatment process

[0090] In the heat treatment process of this embodiment 2, the temperature is raised with the furnace, quenched at 900°C, kept warm for 9 minutes, tempered at 220°C, and kept warm for 18 minutes.

[0091] 3. Product organization and performance testing:

[0092] The steel strip produced in Example 2 was subjected to organizational and performance tests, wherein the performance indicators of the tests are shown in Table 2, and the metallographic structure is shown in Table 2. Figure 2 :

[0093] Table 2 Performance index of steel strip in Example 2

[0094]

[0095] From Table 2 above and Figure 2 It can be seen that the wear-resistant steel produced in Example 2 has improved elongation after fracture, meeting the requirements of mechanical properties such as strength, plasticity, and toughness, and the metallographic structure is mainly martensite + a small amount of ferrite.

[0096] Example 3

[0097] In this embodiment 3, low-cost Brinell hardness 500 HBW grade wear-resistant steel is manufactured using a production line of Bengang Plate Co., Ltd. The product specification is 5.0 mm*1500 mm, and the manufacturing steps are as follows:

[0098] 1. Chemical composition design

[0099] In this embodiment 3, the chemical composition of the wear-resistant steel is designed to be, calculated in the following mass percentages: C: 0.19%, Si: 0.27%, Mn: 1.41%, P: 0.018%, S: 0.003%, Al: 0.024%, Nb: 0.022%, B: 0.0022%, Ti: 0.031%, Cr: 0.31%, O: 0.0032%, and the remainder is Fe and unavoidable impurities.

[0100] 2. Manufacturing process steps

[0101] In this embodiment 3, the manufacturing process and process parameters of the wear-resistant steel are as follows:

[0102] 1. Steelmaking process

[0103] In this embodiment 2, the production route adopted for steelmaking includes converter combined blowing, LF refining and slab continuous casting. During the continuous casting process, the outlet temperature of the heating furnace is 1254° C. and the time in the furnace is 208 minutes.

[0104] 2. Hot rolling process

[0105] In this embodiment 2, 2300 production line is used for rolling, the outlet temperature of rough rolling R1 is 1021°C, the outlet temperature of R2 is 1097°C, three rolling passes are performed respectively, dephosphorization is performed in each pass, and the thickness of the intermediate billet is 35 mm.

[0106] The inlet temperature of finishing rolling F1 is 1045℃, the final rolling temperature is 883℃, and the finishing rolling is to a thickness of 5mm; dephosphorization is performed in each pass of rough rolling and finishing rolling, and the water pressure is 233bar.

[0107] After finishing rolling, intermittent cooling mode is adopted and the coiling temperature is 676℃.

[0108] 3. Heat treatment process

[0109] In the heat treatment process of this embodiment 3, the temperature is raised with the furnace, quenched at 880°C, kept warm for 9 minutes, tempered at 240°C, and kept warm for 20 minutes.

[0110] 3. Product organization and performance testing:

[0111] The steel strip produced in Example 3 was subjected to organizational and performance tests, wherein the performance indicators of the tests are shown in Table 3, and the metallographic structure is shown in Table Figure 3 :

[0112] Table 3 Performance index of steel strip in Example 3

[0113]

[0114] From Table 3 above and Figure 3It can be seen that the wear-resistant steel produced in Example 3 has improved elongation after fracture, meeting the requirements of mechanical properties such as strength, plasticity, and toughness, and the metallographic structure is mainly martensite + a small amount of ferrite.

[0115] Comparative Example 1

[0116] In this comparative example 1, low-cost Brinell hardness 500 HBW grade wear-resistant steel is manufactured for a domestic steel enterprise with a product specification of 6.0 mm*1510 mm.

[0117] In this comparative example 1, the chemical composition of the wear-resistant steel is designed to be, calculated in the following mass percentages: C: 0.21%, Si: 0.72%, Mn: 1.72%, P: 0.019%, S: 0.005%, Al: 0.029%, Nb: 0.025%, B: 0.0023%, Ti: 0.031%, Cr: 0.45%, O: 0.0031%, and the remainder is Fe and unavoidable impurities.

[0118] Product structure and performance test: The steel strip produced in this comparative example 1 was subjected to structure and performance tests, wherein the performance indicators of the tests are shown in Table 4 and Figure 4 :

[0119] Table 4 Performance indexes of comparative steel strip

[0120]

[0121] From Table 4 and Figure 4 Combining Table 3 and Figure 3 It can be seen that the wear-resistant steel produced in this comparative example 1 has a yield strength and tensile strength comparable to those of Example 3, and a relatively lower elongation after fracture. The C, Mn, and Cr elements are higher in cost, and the cost is higher. While meeting the requirements of mechanical properties such as strength, plasticity, and toughness, the metallographic structure is mainly martensite + a small amount of ferrite.

[0122] The above-described embodiments are only embodiments of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present disclosure. It should be noted that, for a person of ordinary skill in the art, without departing from the concept of the present disclosure, several variations, equivalent substitutions, improvements, etc. may be made, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure shall be subject to the attached claims.

Claims

1. A low-cost wear-resistant steel with a Brinell hardness of 500 HBW, characterized in that: Its chemical composition by mass percentage is: C: 0.18%~0.25%, Si: 0.25%~0.40%, Mn: 1.3%~1.7%, S: ≤0.03%, P: ≤0.03%, Al: 0.015%~0.055%, Nb: 0.015~0.035, Ti: 0.020~0.045%, Cr: 0.3%-0.45%, B: 0.0005~0.0030%, O: ≤0.004%, N: ≤0.006%, the rest are Fe and other unavoidable impurities.

2. The method for manufacturing low-cost wear-resistant steel with Brinell hardness of 500 HBW as claimed in claim 1 comprises a steelmaking process, a hot rolling process and a heat treatment process, wherein the steelmaking process comprises a molten iron pretreatment, a converter process, a refining process and a continuous casting process, and the hot rolling process comprises a rough rolling process, a finishing rolling process, a cooling process and a coiling process, and is characterized in that: In the finishing process and the coiling process, the finishing outlet temperature is controlled to be 860-900°C, and the finishing rolling is performed to a thickness of 2.0-12.0 mm; the coiling temperature is controlled to be 660-700°C, and the cooling mode adopts an intermittent cooling mode; The control parameters of the heat treatment process are: quenching at 880°C to 920°C, heating with the furnace, keeping warm for 5 to 10 minutes, tempering at 200 to 240°C, and keeping warm for 15 to 25 minutes.

3. The method for manufacturing low-cost Brinell hardness 500 HBW grade wear-resistant steel according to claim 2, characterized in that: In the rough rolling process, the rough rolling passes adopt a mode of R1 rolling back and forth 3 times and R2 rolling back and forth 3 times, and the thickness of the rough rolling intermediate billet is 30-40 mm; The rough rolling and the finish rolling are each subjected to dephosphorization treatment, and the water pressure is 200-250 bar.

4. The method for manufacturing low-cost wear-resistant steel with Brinell hardness of 500 HBW according to claim 3, characterized in that: In the hot rolling process, the slab furnace temperature is controlled to be 1200-1280°C, and the furnace time is 150-250 minutes; In the cooling process, a slow cooling treatment is performed in a hot zone in a warehouse after the hot rolling.

5. The method for manufacturing low-cost Brinell hardness 500 HBW grade wear-resistant steel according to claim 4, characterized in that: During the molten iron pretreatment, the molten iron pretreatment S is controlled to be ≤0.003% before entering the furnace, and the slag is removed; refined scrap steel is used; and the slag amount of the molten iron entering the converter is ≤20mm.

6. The method for manufacturing low-cost wear-resistant steel with Brinell hardness of 500 HBW according to claim 5, characterized in that: In the converter process, the endpoint oxygen is controlled to be 400ppm-700ppm; repeated blowing is performed, and supplementary blowing is prohibited; the steel tapping time is 4min-8min; and the ladle slag thickness is ≤70mm.

7. The method for manufacturing low-cost wear-resistant steel with Brinell hardness of 500 HBW according to claim 6, characterized in that: In the refining process, LF furnace refining treatment is adopted, and the LF furnace refining treatment process maintains a slightly positive pressure, and the nitrogen increase is ≤10ppm; active lime and fluorite are used to make reducing slag, and the argon blowing intensity is controlled to avoid exposure of molten steel; silicon calcium wire is used for calcium treatment.

8. The method for manufacturing low-cost wear-resistant steel with Brinell hardness of 500 HBW according to claim 7, characterized in that: In the continuous casting process, the tundish casting tonnage is adopted, the tundish superheat control target is ≤25°C, the constant casting speed is ≤1.2m / min, and the crystallizer liquid level fluctuation is ≤±3mm.

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