Hot rolling forming process for arc flat steel of wear-resisting plate of high-wear-resisting excavator bucket

Abstract

The invention relates to the technical field of wear-resistant steel hot rolling forming, and discloses a high-wear-resistant excavator bucket wear-resistant plate arc flat steel hot rolling forming process which comprises the steps of S1 steel billet preparation, S2 heating process, S3 hot rolling forming, S4 cooling after rolling, S5 finishing treatment and S6 finished product inspection. By optimizing the steel billet chemical component range (precisely controlling the contents of C, Cr and Mo alloy elements) and cooperating with a segmented heating process of slow preheating and uniform high-temperature heating and a tooth separation step steel air cooling mode, the hot brittleness of the wear-resistant steel is effectively inhibited, casting blank cracking and surface defects are reduced, the steel billet surface quality qualification rate is remarkably increased, and the production efficiency is improved. And the center of the macrostructure is loose, the general loose index is controlled at the high-quality level, and the production yield is improved by more than 15% compared with that of the traditional process.

Description

Technical Field

[0001] This invention relates to the field of hot rolling forming technology of wear-resistant steel, specifically a hot rolling forming process for arc flat steel of high wear-resistant excavator bucket wear-resistant plate. Background Technology

[0002] Wear-resistant flat steel is a core wear-resistant component of construction machinery (such as excavator buckets), and its performance directly affects the service life and operating efficiency of the equipment. Currently, the mainstream production method of wear-resistant strips in the industry is to cut plates into square steel and then process them. This method has the problems of low material utilization, cumbersome cutting process, and high production cost. Moreover, traditional right-angle square steel requires a large amount of welding flux to ensure the welding strength during welding assembly, resulting in low welding efficiency and insufficient welding reliability.

[0003] Meanwhile, due to its inherent alloy composition, wear-resistant steel suffers from significant hot brittleness, a major technical challenge. During production, defects such as cracks and folds easily occur on the surface of the cast billet, making dimensional accuracy difficult to control, and resulting in frequent occurrences of uneven thickness and excessive curvature. Furthermore, existing processes lack sufficient control over heating and heat treatment parameters, easily leading to temper brittleness and uneven material mechanical properties. It is difficult to simultaneously achieve high tensile strength, impact absorption energy, and hardness, and the high content of non-metallic inclusions further affects the wear resistance and service stability of wear-resistant steel, failing to fully meet the high-strength and high-wear-resistance requirements of engineering machinery under extreme working conditions. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a hot rolling forming process for high wear-resistant bucket wear-resistant plate arc flat steel, which has advantages such as improved production stability and solves the problem of significant hot brittleness.

[0005] (II) Technical Solution To achieve the above-mentioned goal of improving production stability, the present invention provides the following technical solution: A hot rolling forming process for high wear-resistant bucket wear-resistant plate arc flat steel, including S1 billet preparation, S2 heating process, S3 hot rolling forming, S4 post-rolling cooling, S5 finishing treatment and S6 finished product inspection, wherein S1 billet preparation includes S101 billet specifications, S102 chemical composition control (wt%) and S103 billet treatment; The S2 heating process includes the S201 preheating stage, the S202 high-temperature heating stage, and the S203 total heating time. Among them, S3 hot rolling forming includes S301 rolling equipment, S302 rolling temperature, S303 rolling passes and S304 finished product specification control. Among them, S4 post-rolling cooling includes S401 cooling method and S402 cooling parameters; Among them, the S5 finishing process includes S501 surface cleaning, S502 straightening treatment and S503 length cutting; Among them, the S6 finished product inspection includes S601 dimensional and shape inspection, S602 surface quality inspection, S603 low magnification microstructure inspection, S604 non-metallic inclusion inspection, S605 mechanical property inspection and S606 metallographic microstructure inspection.

[0006] Preferably, the S101 steel billet specifications are as follows: a rectangular cross-section continuous casting billet with cross-sectional dimensions controlled at 250-280mm×250-280mm and a length of 6-8m, to ensure that the billet length matches the subsequent rolling rhythm; S102 chemical composition control (wt%): C 0.24-0.33%, Si 0.15-0.75%, Mn 0.65-1.55%, P≤0.018%, S≤0.008%, Cr 0.35-1.55%, Mo≤0.65%, Ti≤0.06%, B 0.0005-0.0045%, CEV≤0.55%, the remainder being trace elements.

[0007] Preferably, the S103 billet treatment involves flame cutting or mechanical processing to clean the surface of the billet, removing iron oxide scale, cracks, folds, and scabs. After cleaning, the surface is free of visually visible defects, and the width of local defects is not less than 5 times the cleaning depth, ensuring that the surface quality of the billet meets the rolling requirements.

[0008] Preferably, in the S201 preheating stage: the steel billet is sent into the preheating section of the heating furnace, the heating temperature is controlled at 650-750℃, the holding time is 40-60min, and a slow heating method is adopted to avoid excessive temperature difference between the inside and outside of the steel billet, which would generate thermal stress. S202 High-temperature heating stage: After preheating, it enters the high-temperature section with a heating temperature of 1080-1130℃ and a holding time of 110-150min to ensure uniform internal temperature of the billet and full solid solution of alloying elements, and to avoid overheating and burning. Total heating time for S203: 240-420 min, adjusted according to the cross-sectional dimensions of the billet to ensure thorough heating and meet the requirements for rolling plasticity.

[0009] Preferably, the S301 rolling equipment adopts a bar rolling production line, is equipped with a multi-pass pass system, and the pass design is based on a circular arc cross-section with a radius of r = t / 2 (t is the thickness of the flat steel). The pass only controls the shape of the circular arc and is not used as the final acceptance criterion. S302 rolling temperature: initial rolling temperature 1050-1100℃, final rolling temperature 850-900℃. Temperature control ensures the plasticity and forming quality of the steel, and avoids excessive rolling force or cracking of the steel due to excessively low final rolling temperature. S303 rolling passes: The number of passes is reasonably allocated according to the billet size and finished product specifications, with a total of 8-12 passes. The circular arc section is gradually formed, and the amount of reduction in each pass is controlled to avoid excessive local deformation and defects.

[0010] Preferably, the finished S304 product specifications are controlled as follows: the finished flat steel thickness is 20-32mm, the width is 80-125mm, and the allowable dimensional deviations are: thickness ±0.30-0.40mm, width ±0.60-0.80mm; the thickness difference on the same cross-sectional plane is not greater than 50% of the thickness tolerance, and there is no protrusion in the middle of the wide surface.

[0011] Preferably, the S401 cooling method is as follows: the rolled steel billet is immediately fed into the cooling bed, and the steel is arranged with a toothed step to avoid the steel from contacting each other and causing uneven cooling. The cooling bed adopts a natural air cooling method. S402 cooling parameters: The cooling rate is controlled at 5-15℃ / min, and the final cooling temperature is ≤300℃ to ensure that the steel cools slowly, reduce internal stress, and avoid cracks and deformation defects; the insulation cover is removed in time during the cooling process to shorten the cooling cycle and ensure cooling uniformity.

[0012] Preferably, the surface cleaning in step S501 involves using mechanical cleaning methods to remove iron oxide scale, indentations, and scratches from the steel surface, and the use of chisels for cleaning is prohibited; after cleaning local defects, the steel size shall not be smaller than the minimum allowable size.

[0013] Preferably, the S502 straightening process involves straightening the cooled flat steel to control the curvature: side bends ≤ 3.0 mm per meter, total curvature ≤ 0.35%; flat bends ≤ 5.0 mm per meter, total curvature ≤ 0.55%, ensuring no side or flat bends that affect use; S503 Fixed-length cutting: Fixed-length or multiple-length cutting is performed according to requirements. The standard length is 4-7.5m; the short length is not less than 4m, and its weight does not exceed 12% of the total delivery weight; when delivering fixed-length or multiple-length items, the length deviation is allowed to be 0-+60mm.

[0014] Preferably, the S601 dimensional and shape inspection involves using a measuring tool with an accuracy of ≥0.02mm to inspect the thickness, width, radius of curvature, and curvature batch by batch to ensure compliance with process requirements. S602 Surface Quality Inspection: Visually inspect the surface or use a magnifying glass to ensure there are no defects such as cracks, folds, scratches, scabs, delamination, or pressed-in iron oxide scale that would affect its use. S603 Low-magnification microstructure inspection: According to GB / T1979 rating, the cross-section acid-etched low-magnification microstructure has no shrinkage cavities, bubbles, or cracks. The central porosity, general porosity, ingot segregation, and central segregation are all ≤2.0 grade. S604 Non-metallic inclusion inspection: Determined according to Method A in GB / T10561, for fine inclusions of categories A, B, C, and D, the grade is ≤2.5; for coarse inclusions, the grade is ≤1.5; and for inclusions Ds, the grade is ≤1.5. S605 mechanical property test: tensile strength 1450-1650MPa, yield strength 1200-1300MPa, elongation 7-9%, impact absorption energy at 20℃ ≥24J, surface Brinell hardness 460-490HBW. Metallographic examination of S606: The microstructure after heat treatment is tempered martensite.

[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a hot rolling forming process for high wear-resistant bucket wear-resistant plate arc flat steel, which has the following beneficial effects: 1. The hot rolling forming process of the arc section of NM500 wear-resistant flat steel solves the problem of hot brittleness and improves production stability: By optimizing the range of chemical composition of steel billet (precisely controlling the content of C, Cr, and Mo alloying elements), combined with the segmented heating process of "slow preheating + uniform high temperature heating" and the air cooling method of toothed step steel, the hot brittleness of wear-resistant steel is effectively suppressed, the cracking of billet and the generation of surface defects are reduced, the surface quality qualification rate of billet is significantly improved, and the central porosity and general porosity in low magnification structure are controlled at the excellent level. The production yield is more than 15% higher than that of traditional processes.

[0016] 2. The NM500 wear-resistant flat steel features a hot-rolled arc section forming process that achieves dimensional accuracy and meets assembly requirements. This process employs a multi-pass rolling system combined with targeted finishing and straightening processes to strictly control the thickness deviation (±0.30-0.40mm), width deviation (±0.60-0.80mm), and curvature (lateral bend ≤3.0mm per meter, horizontal bend ≤5.0mm per meter) of the finished flat steel. The thickness difference within the same cross-section does not exceed 50% of the thickness tolerance, and there are no protrusions on the wide surface. This fully meets the assembly accuracy requirements of wear-resistant strips for engineering machinery, reducing subsequent processing and adjustment steps.

[0017] 3. The NM500 wear-resistant flat steel features a circular arc section hot rolling forming process, which optimizes welding performance and reduces usage costs: the circular arc section design combined with an optimized bevel structure requires less welding flux to achieve welding strength higher than that of traditional right-angle square steel (tensile strength can reach over 180MPa, and welding strength is increased by 30%). This not only reduces welding material consumption and welding costs but also improves welding efficiency, making it suitable for the assembly needs of new buckets in engineering machinery development.

[0018] 4. The NM500 wear-resistant flat steel features a hot-rolled arc section forming process that achieves balanced mechanical properties and extends wear life. By precisely controlling the quenching and tempering temperatures (avoiding the tempering brittle zone around 280℃), the metallographic structure is optimized to uniform tempered martensite, resulting in a stable tensile strength of 1450-1650MPa, a yield strength of 1200-1300MPa, and a surface Brinell hardness of 460-490HBW. Simultaneously, it maintains an elongation of 7-9% and an impact absorption energy of ≥24J, exhibiting excellent strength-ductility product. Its wear resistance is more than 20% higher than that of traditional cut square steel, significantly extending the service life of excavator bucket components.

[0019] 5. The hot rolling forming process of the arc section of the NM500 wear-resistant flat steel improves material utilization and reduces production costs: the direct hot rolling forming process of rectangular continuous casting billets replaces the traditional plate cutting method, avoiding material waste during the cutting process. The material utilization rate is increased from about 75% in the traditional process to more than 90%. At the same time, the production process is simplified, the production cycle is shortened, and the overall production cost is reduced by 10-15%, which has significant economic benefits. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] This solution provides a technical approach, specifically a hot-rolling forming process for high wear-resistant bucket wear-resistant plate arc flat steel, comprising the following steps: S1 billet preparation: S101 billet specifications: Rectangular cross-section continuous casting billet, with cross-section dimensions controlled at 250-280mm×250-280mm and length of 6-8m, to ensure that the billet length matches the subsequent rolling rhythm; S102 chemical composition control (wt%): C 0.24-0.33%, Si 0.15-0.75%, Mn 0.65-1.55%, P≤0.018%, S≤0.008%, Cr 0.35-1.55%, Mo≤0.65%, Ti≤0.06%, B 0.0005-0.0045%, CEV≤0.55%, the remainder being trace elements; S103 billet treatment: The surface of the billet is cleaned by flame cutting or mechanical processing to remove iron oxide scale, cracks, folds, and scabs. After cleaning, there are no visible defects on the surface. The width of the local defect cleaning is not less than 5 times the cleaning depth to ensure that the surface quality of the billet meets the rolling requirements. S2 heating process: S201 Preheating Stage: The steel billet is sent into the preheating section of the heating furnace. The heating temperature is controlled at 650-750℃ and the holding time is 40-60 minutes. A slow heating method is adopted to avoid excessive temperature difference between the inside and outside of the steel billet, which will generate thermal stress. S202 High-temperature heating stage: After preheating, it enters the high-temperature section with a heating temperature of 1080-1130℃ and a holding time of 110-150min to ensure uniform internal temperature of the billet and full solid solution of alloying elements, and to avoid overheating and burning. Total heating time for S203: 240-420 min, adjusted according to the cross-sectional dimensions of the billet to ensure thorough heating and meet the requirements for rolling plasticity; S3 hot rolling forming: S301 Rolling Equipment: It adopts a bar rolling production line and is equipped with a multi-pass pass system. The pass design is based on the arc cross-section, with the arc radius r=t / 2 (t is the thickness of the flat steel). The pass only controls the arc shape and is not used as the final acceptance criterion. S302 rolling temperature: initial rolling temperature 1050-1100℃, final rolling temperature 850-900℃. Temperature control ensures the plasticity and forming quality of the steel, and avoids excessive rolling force or cracking of the steel due to excessively low final rolling temperature. S303 rolling passes: The number of passes is reasonably allocated according to the billet size and finished product specifications, with a total of 8-12 passes. The circular arc section is gradually formed, and the amount of reduction in each pass is controlled to avoid excessive local deformation and defects. S304 Finished Product Specification Control: Finished flat steel thickness 20-32mm, width 80-125mm, dimensional tolerance: thickness ±0.30-0.40mm, width ±0.60-0.80mm; thickness difference on the same cross-sectional plane shall not exceed 50% of the thickness tolerance, and there shall be no protrusion in the middle of the wide face; S4 post-rolling cooling: S401 Cooling method: The rolled steel billet is immediately sent to the cooling bed, and the toothed step steel is arranged to avoid the steel materials from contacting each other and causing uneven cooling. The cooling bed adopts natural air cooling. S402 cooling parameters: The cooling rate is controlled at 5-15℃ / min, and the final cooling temperature is ≤300℃ to ensure that the steel cools slowly, reduce internal stress, and avoid cracks and deformation defects; the insulation cover is removed in time during the cooling process to shorten the cooling cycle and ensure cooling uniformity. S5 finishing process: S501 Surface Cleaning: Use mechanical cleaning methods to remove iron oxide scale, indentations, and scratches from the steel surface. Chiseling is prohibited. After cleaning local defects, the steel dimensions shall not be smaller than the minimum allowable dimensions. S502 Straightening Treatment: Straighten the cooled flat steel to control the curvature: side bend ≤ 3.0mm per meter, total curvature ≤ 0.35%; flat bend ≤ 5.0mm per meter, total curvature ≤ 0.55%, ensuring no side bends or flat bends that affect use; S503 Fixed-length cutting: Fixed-length or multiple-length cutting is performed according to requirements. The standard length is 4-7.5m; the short length is not less than 4m, and its weight does not exceed 12% of the total delivery weight; when delivering fixed-length or multiple-length items, the length deviation is allowed to be 0-+60mm. S6 Finished Product Inspection: S601 Dimensional and shape inspection: Using measuring tools with an accuracy of ≥0.02mm, inspect the thickness, width, radius of curvature, and curvature of each batch to ensure compliance with process requirements; S602 Surface Quality Inspection: Visually inspect the surface or use a magnifying glass to ensure there are no defects such as cracks, folds, scratches, scabs, delamination, or pressed-in iron oxide scale that would affect its use. S603 Low-magnification microstructure inspection: According to GB / T1979 rating, the cross-section acid-etched low-magnification microstructure has no shrinkage cavities, bubbles, or cracks. The central porosity, general porosity, ingot segregation, and central segregation are all ≤2.0 grade. S604 Non-metallic inclusion inspection: Determined according to Method A in GB / T10561, for fine inclusions of categories A, B, C, and D, the grade is ≤2.5; for coarse inclusions, the grade is ≤1.5; and for inclusions Ds, the grade is ≤1.5. S605 mechanical property test: tensile strength 1450-1650MPa, yield strength 1200-1300MPa, elongation 7-9%, impact absorption energy at 20℃ ≥24J, surface Brinell hardness 460-490HBW. Metallographic examination of S606: The microstructure after heat treatment is tempered martensite. Furthermore, this process solves the problem of hot brittleness and improves production stability: by optimizing the range of chemical composition of steel billets (precisely controlling the content of C, Cr, and Mo alloying elements), combined with the segmented heating process of "slow preheating + uniform high-temperature heating" and the air cooling method of toothed step steel, the hot brittleness of wear-resistant steel is effectively suppressed, the cracking of billets and the generation of surface defects are reduced, the surface quality qualification rate of steel billets is significantly improved, and the central porosity and general porosity in low magnification structure are controlled at the excellent level, and the production yield is more than 15% higher than that of traditional processes; Furthermore, this process achieves dimensional accuracy and adapts to assembly requirements: it adopts a multi-pass rolling system combined with targeted finishing and straightening processes to strictly control the thickness deviation (±0.30-0.40mm), width deviation (±0.60-0.80mm), and curvature (side bend ≤3.0mm per meter, flat bend ≤5.0mm per meter) of the finished flat steel. The thickness difference on the same cross-sectional plane does not exceed 50% of the thickness tolerance, and there are no protrusions on the wide surface, which fully meets the assembly accuracy requirements of wear-resistant strips for engineering machinery and reduces subsequent processing and adjustment procedures. Furthermore, this process optimizes welding performance and reduces usage costs: the arc cross-section design combined with the optimized bevel structure requires less welding flux to achieve welding strength higher than that of traditional right-angle square steel (tensile strength can reach over 180MPa, welding strength increased by 30%), which not only reduces welding material consumption and welding costs, but also improves welding efficiency, adapting to the assembly needs of new bucket development in engineering machinery. Furthermore, this process achieves balanced mechanical properties and extends wear life: by precisely controlling the quenching and tempering temperatures (avoiding the tempering brittle zone of around 280℃), the metallographic structure is optimized into uniform tempered martensite, making the tensile strength of the product stable at 1450-1650MPa, the yield strength at 1200-1300MPa, and the surface Brinell hardness at 460-490HBW, while maintaining an elongation of 7-9% and an impact absorption energy of ≥24J. It has excellent strength-ductility product and wear resistance is more than 20% higher than that of traditional cut square steel, significantly extending the service life of excavator bucket components. Furthermore, this process improves material utilization and reduces production costs: it adopts a direct hot rolling forming process for rectangular continuous casting billets, replacing the traditional plate cutting method, avoiding material waste during the cutting process, increasing material utilization from about 75% in the traditional process to over 90%, while simplifying the production process, shortening the production cycle, and reducing overall production costs by 10-15%, resulting in significant economic benefits. Furthermore, this process achieves improved purity and enhanced stability in use: through strict cleaning of the billet surface and control of non-metallic inclusions (fine series A, B, C, and D ≤ 2.5 grade, coarse series ≤ 1.5 grade), cracks and internal defects are reduced, the material structure is purer, and the fatigue resistance and stability in use under extreme conditions in the Sahara Desert and Antarctica are greatly improved, making it suitable for the all-domain operation needs of engineering machinery.

[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hot-rolling forming process for high wear-resistant bucket wear-resistant plate arc flat steel, comprising S1 billet preparation, S2 heating process, S3 hot rolling forming, S4 post-rolling cooling, S5 finishing treatment, and S6 finished product inspection, characterized in that: The preparation of the S1 billet includes the S101 billet specifications, the S102 chemical composition control (wt%), and the S103 billet treatment. The S2 heating process includes the S201 preheating stage, the S202 high-temperature heating stage, and the S203 total heating time. Among them, S3 hot rolling forming includes S301 rolling equipment, S302 rolling temperature, S303 rolling passes and S304 finished product specification control. Among them, S4 post-rolling cooling includes S401 cooling method and S402 cooling parameters; Among them, the S5 finishing process includes S501 surface cleaning, S502 straightening treatment and S503 length cutting; Among them, the S6 finished product inspection includes S601 dimensional and shape inspection, S602 surface quality inspection, S603 low magnification microstructure inspection, S604 non-metallic inclusion inspection, S605 mechanical property inspection and S606 metallographic microstructure inspection.

2. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S101 steel billet specifications are as follows: a rectangular cross-section continuous casting billet is adopted, with the cross-section size controlled at 250-280mm×250-280mm and the length at 6-8m, to ensure that the billet length matches the subsequent rolling rhythm. S102 chemical composition control (wt%): C 0.24-0.33%, Si 0.15-0.75%, Mn 0.65-1.55%, P≤0.018%, S≤0.008%, Cr 0.35-1.55%, Mo≤0.65%, Ti≤0.06%, B 0.0005-0.0045%, CEV≤0.55%, the remainder being trace elements.

3. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S103 billet treatment involves flame cutting or mechanical processing to clean the surface of the billet, removing iron oxide scale, cracks, folds, and scabs. After cleaning, the surface should be free of visually visible defects, and the width of any local defects should be no less than 5 times the cleaning depth to ensure that the surface quality of the billet meets the rolling requirements.

4. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S201 preheating stage: the steel billet is sent into the preheating section of the heating furnace, the heating temperature is controlled at 650-750℃, the holding time is 40-60min, and a slow heating method is adopted to avoid excessive temperature difference between the inside and outside of the steel billet and the generation of thermal stress. S202 High-temperature heating stage: After preheating, it enters the high-temperature section with a heating temperature of 1080-1130℃ and a holding time of 110-150min to ensure uniform internal temperature of the billet and full solid solution of alloying elements, and to avoid overheating and burning. Total heating time for S203: 240-420 min, adjusted according to the cross-sectional dimensions of the billet to ensure thorough heating and meet the requirements for rolling plasticity.

5. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S301 rolling equipment adopts a bar rolling production line and is equipped with a multi-pass pass system. The pass design is based on a circular arc cross-section, with the arc radius r = t / 2 (t is the thickness of the flat steel). The pass only controls the arc shape and is not used as the final acceptance criterion. S302 rolling temperature: initial rolling temperature 1050-1100℃, final rolling temperature 850-900℃. Temperature control ensures the plasticity and forming quality of the steel, and avoids excessive rolling force or cracking of the steel due to excessively low final rolling temperature. S303 rolling passes: The number of passes is reasonably allocated according to the billet size and finished product specifications, with a total of 8-12 passes. The circular arc section is gradually formed, and the amount of reduction in each pass is controlled to avoid excessive local deformation and defects.

6. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The specifications of the S304 finished product are controlled as follows: the thickness of the finished flat steel is 20-32mm and the width is 80-125mm. The allowable deviation of the dimensions is: thickness ±0.30-0.40mm and width ±0.60-0.80mm. The thickness difference in the same cross-sectional plane shall not exceed 50% of the thickness tolerance, and there shall be no protrusion in the middle of the wide surface.

7. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S401 cooling method is as follows: the rolled steel billet is immediately sent into the cooling bed, and the toothed step steel is arranged to avoid the steel materials from contacting each other and causing uneven cooling. The cooling bed adopts natural air cooling. S402 cooling parameters: The cooling rate is controlled at 5-15℃ / min, and the final cooling temperature is ≤300℃ to ensure that the steel cools slowly, reduce internal stress, and avoid cracks and deformation defects; the insulation cover is removed in time during the cooling process to shorten the cooling cycle and ensure cooling uniformity.

8. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S501 surface cleaning procedure involves using mechanical cleaning methods to remove iron oxide scale, indentations, and scratches from the steel surface. Chiseling is prohibited. After cleaning local defects, the steel dimensions must not be smaller than the minimum allowable dimensions.

9. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The S502 straightening process involves straightening the cooled flat steel to control the curvature: side bends ≤ 3.0 mm per meter, total curvature ≤ 0.35%; flat bends ≤ 5.0 mm per meter, total curvature ≤ 0.55%, ensuring no side or flat bends that affect use. S503 Fixed-length cutting: Fixed-length or multiple-length cutting is performed according to requirements. The standard length is 4-7.5m; the short length is not less than 4m, and its weight does not exceed 12% of the total delivery weight; when delivering fixed-length or multiple-length items, the length deviation is allowed to be 0-+60mm.

10. The hot rolling forming process of high wear-resistant bucket wear-resistant plate arc flat steel according to claim 1, characterized in that: The dimensions and shape of S601 are inspected: using measuring tools with an accuracy of ≥0.02mm, the thickness, width, radius of curvature, and curvature are inspected batch by batch to ensure compliance with process requirements; S602 Surface Quality Inspection: Visually inspect the surface or use a magnifying glass to ensure there are no defects such as cracks, folds, scratches, scabs, delamination, or pressed-in iron oxide scale that would affect its use. S603 Low-magnification microstructure inspection: According to GB / T1979 rating, the cross-section acid-etched low-magnification microstructure has no shrinkage cavities, bubbles, or cracks. The central porosity, general porosity, ingot segregation, and central segregation are all ≤2.0 grade. S604 Non-metallic inclusion inspection: Determined according to Method A in GB / T10561, for fine inclusions of categories A, B, C, and D, the grade is ≤2.5; for coarse inclusions, the grade is ≤1.5; and for inclusions Ds, the grade is ≤1.

5. S605 mechanical property test: tensile strength 1450-1650MPa, yield strength 1200-1300MPa, elongation 7-9%, impact absorption energy at 20℃ ≥24J, surface Brinell hardness 460-490HBW. Metallographic examination of S606: The microstructure after heat treatment is tempered martensite.