Hot-rolled weather-resistant steel plate for road guardrail and preparation method thereof

Abstract

The invention discloses a hot-rolled weather-resistant steel plate for a road guardrail and a preparation method of the hot-rolled weather-resistant steel plate, and belongs to the technical field of weather-resistant steel. According to the hot-rolled weather-resistant steel plate for the road guardrail and the preparation method of the hot-rolled weather-resistant steel plate, by reasonably designing alloy components and matching with heating, rough rolling, finish rolling, laminar cooling and coiling processes, the contradiction between high strength and high plasticity is solved, industrial production of the hot-rolled weather-resistant steel plate for the road guardrail with the thickness of 2.5-4.0 mm is achieved, the yield strength of the hot-rolled weather-resistant steel plate is larger than or equal to 500 MPa, and the tensile strength of the hot-rolled weather-resistant steel plate is larger than or equal to 100 MPa. The tensile strength is larger than or equal to 600 MPa, the percentage elongation after fracture is larger than or equal to 30%, the 180-degree bending test D is equal to a, the corrosion resistance index I reaches 5.5-6.7, and the energy consumption of a single-section guardrail can be larger than or equal to 7.92 * 10 < 5 > J, so that lightweight application can be achieved, and the safety of the guardrail is guaranteed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of weathering steel, and particularly relates to a hot-rolled weathering steel plate for a highway guardrail and a preparation method thereof. BACKGROUND

[0002] With the rapid economic development and accelerated urbanization process, in the fields of expressways, provincial highways and the like, the highway guardrail has developed into a necessary supporting facility as an important traffic safety protection facility, can absorb energy when a vehicle collides, prevents the vehicle from running off the road, thereby protecting the vehicle and passengers, and reducing the loss caused by the accident, so the guardrail material is required to have high strength and good plasticity to ensure that the guardrail is not destroyed and to improve the energy absorption rate of the collision. Meanwhile, due to the complexity of the service environment of the highway guardrail, the guardrail material will be eroded by various types of corrosive media in the use process, so the guardrail material needs to have good corrosion resistance to improve the safety of the highway guardrail and prolong the service life thereof.

[0003] At present, the guardrail material basically adopts structural steel such as Q235 and Q355, the material strength is low, and the corrosion resistance of the material is improved through a hot-dip galvanizing process and the like, which increases the process cost and the risk of environmental pollution. With the increase of the density of the traffic network such as expressways and the increase of the vehicle load and speed, the highway guardrail made of the traditional low-strength steel material is difficult to meet the impact resistance requirement, so it is necessary to apply high-strength high-plasticity steel to provide higher strength and ensure excellent plastic deformation capacity under the same thickness, thereby effectively improving the energy consumption rate of the material, to reduce the risk of deformation or fracture of the guardrail and improve the accident protection capacity.

[0004] CN112647018A discloses a low-alloy high-strength high-weathering structural steel for a highway guardrail and a preparation method thereof. The chemical composition of the structural steel is as follows: C≤0.12%; Si≤0.65%; Mn≤1.20%; P 0.07-0.12%; S≤0.030%; Cu 0.20-0.55%; Cr 0.30-1.25%; Ni 0.12-0.65%; Nb≤0.03%; Al≤0.05%, and Fe is the balance. The product has a high P content and a low Nb content, which is easy to cause the plasticity to decrease; the yield strength at room temperature is greater than 415 MPa, the tensile strength is between 580 MPa and 700 MPa, the elongation is greater than or equal to 26%, and the reduction of area is greater than or equal to 70%, wherein the yield strength and the elongation are low, which is not conducive to ensuring the safety of the highway guardrail.

[0005] CN115637386A discloses a high-strength weather-resistant steel for high-plastic highway guardrails and a preparation method of the highway guardrails, and the high-strength weather-resistant steel has the following chemical components in mass percentage: C 0.10-0.12%, Si 0.08-0.10%, Mn 1.00-1.2%, Cu 0.1-0.15%, Al 0.05-0.1%, Ti 0.05-0.08%, P 0.03-0.05%, S 0.01-0.02%, O 0.003-0.005%, N 0.001-0.003%, and the balance of Fe and inevitable impurities. The product has high C, P and Ti contents, and contains martensite in the structure, which is easy to cause the decrease of plasticity; the product needs to be subjected to complex surface treatment, and the process is complex and the production cost is high. SUMMARY

[0006] To solve the above technical problems, the present application provides a hot-rolled weather-resistant steel plate for highway guardrails and a preparation method thereof.

[0007] The present application first provides a preparation method of a hot-rolled weather-resistant steel plate for highway guardrails, and the hot-rolled weather-resistant steel plate for highway guardrails has the following components in percentage by weight: C 0.05-0.07%, Si 0.25-0.35%, Mn 1.10-1.20%, P≤0.020%, S≤0.007%, Cr 0.40-0.50%, Ni 0.12-0.20%, Cu 0.25-0.35%, Nb 0.035-0.045%, Ti 0.010-0.020%, Als 0.010-0.045%, and the balance of Fe and inevitable impurities. The preparation method comprises the following steps: smelting, heating, rough rolling, finish rolling, laminar flow cooling and coiling, to obtain the hot-rolled weather-resistant steel plate for highway guardrails. In the heating step, the heating temperature is 1200-1240℃, and the heating time is 150-250min. In the rough rolling step, the steel plate is subjected to 5 passes of rough rolling, each pass has a deformation amount≥18%, and the intermediate blank thickness is 35-39mm; the scale is removed in the odd passes, and the scale removal water pressure is≥18MPa. In the finish rolling step, the steel plate is subjected to 7 passes of finish rolling, the opening rolling temperature is 1050-1110℃, and the final rolling temperature is 860-900℃. In the coiling step, the coiling temperature is 630-670℃.

[0008] In the above preparation method, the thickness of the hot-rolled weather-resistant steel plate for highway guardrails is 2.5-4.0mm.

[0009] In the preparation method, in the laminar cooling, the strip steel is cooled to 680-720 DEG C at a cooling rate of 60-90 DEG C / s by using the front stage cooling mode, and then air-cooled to the coiling temperature.

[0010] In the preparation method, in the rough rolling, the scale removal is increased when the scale removal is poor.

[0011] In the preparation method, the atmospheric corrosion resistance index I of the hot-rolled weathering steel plate for highway guardrails is 5.5-6.7.

[0012] In the preparation method, the yield strength of the hot-rolled weathering steel plate for highway guardrails is greater than or equal to 500 MPa, the tensile strength is greater than or equal to 600 MPa, the elongation after fracture is greater than or equal to 30%, and the 180-degree bending test D=a.

[0013] In the preparation method, the energy consumption of a single section guardrail made of the hot-rolled weathering steel plate for highway guardrails is greater than or equal to 7.92*10 5 J.

[0014] The application further provides a hot-rolled weathering steel plate for highway guardrails, which is prepared by the preparation method.

[0015] The application has the following beneficial effects: The application solves the contradiction between high strength and high plasticity by reasonable alloy component design and supporting heating, rough rolling, finishing rolling, laminar cooling and coiling process design, realizes industrialized production of the hot-rolled weathering steel plate for highway guardrails, and the product has a thickness of 2.5-4.0 mm, a yield strength of greater than or equal to 500 MPa, a tensile strength of greater than or equal to 600 MPa, an elongation after fracture of greater than or equal to 30%, a 180-degree bending test D=a, and can realize energy consumption of a single section guardrail of greater than or equal to 7.92*10 5 J, so that lightweight application can be realized while the safety of the guardrail is ensured and the loss caused by vehicle collision accidents is reduced; in addition, the corrosion resistance index I of the product reaches 5.5-6.7, the product has good atmospheric corrosion resistance, the cost of corrosion treatment and later maintenance can be effectively reduced, the service life is prolonged, and the whole life cycle cost is reduced; the production method of the product is simple, the product has excellent performance, the product applied to highway guardrails can realize upgrading of the steel for highway guardrails, and meet the requirements of high strength, high plasticity, long service life and green transformation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The metallographic structure diagram of the hot-rolled weathering steel plate for highway guardrails prepared in Example 1 of the application.

[0017] Figure 2 The metallographic structure diagram of the hot-rolled weathering steel plate for highway guardrails prepared in Example 2 of the application. DETAILED DESCRIPTION

[0018] The role and mechanism of each element and main process in the present application: Carbon: Carbon is an effective strengthening element in steel, which can dissolve into the matrix to play a role of solid solution strengthening, and can combine with niobium and titanium to form carbide precipitate particles to play a role of fine-grain strengthening and precipitation strengthening, so increasing the carbon content is beneficial to improving the strength; but too high carbon content is easy to form a segregation band in the center of the steel plate, and martensite structure is easy to form at the segregation band under the condition of large cooling speed, thereby causing the plasticity of the material to decrease. The content of the added alloying elements in the present application is relatively low (Mn is 1.10-1.20%, Nb is 0.035-0.045%, and Ti is 0.010-0.020%), which is not easy to bring more C, and the control difficulty of the C element content is relatively low. Therefore, the value range of C in the present application is appropriately reduced to 0.05-0.08% and is set to 0.05-0.07%.

[0019] Silicon: Silicon can dissolve in ferrite and austenite to improve the hardness and strength of the steel, which is beneficial to refining the rust layer structure and reducing the overall corrosion rate of the steel, but too high content will make it difficult to remove scale during rolling, and at the same time, it is easy to cause the plasticity of the steel to decrease. Therefore, the value range of Si in the present application is set to 0.25-0.35%.

[0020] Manganese: Manganese has a strong solid solution strengthening effect and is an important toughening element, but too much Mn content is easy to cause cracks in the continuous casting process, and may cause composition segregation in the center of the steel plate, and under the condition of large cooling speed, martensite structure is easy to form at the segregation band, thereby causing the plasticity of the material to decrease. Therefore, the value range of Mn in the present application is set to 1.10-1.20%.

[0021] Phosphorus: Although phosphorus element can effectively improve the atmospheric corrosion resistance of the steel and has low cost, too high phosphorus content will significantly reduce the plasticity of the steel. Therefore, the value range of P in the present application is set to P≤0.020%.

[0022] Sulfur: Sulfur element will have an adverse effect on the structure and performance of the steel plate, and too high sulfur content will increase the thermal brittleness tendency of the steel, and sulfur will form sulfide inclusions to deteriorate the performance of the steel. Therefore, the value range of S in the present application is set to S≤0.007%.

[0023] Chromium: Chromium has a significant effect on improving the passivation ability of the steel, which can promote the formation of a dense protective rust layer on the surface of the steel, and the enrichment of chromium in the rust layer can effectively improve the selective permeability of the rust layer to corrosive media; but too high chromium content will increase the production cost, and under the condition of large cooling speed, it is easy to cause the formation of martensite structure to reduce the plasticity of the steel. Therefore, the value range of Cr in the present application is set to 0.40-0.50%.

[0024] Nickel: nickel is added to the steel, which will significantly improve the corrosion resistance of the steel material, at the same time, nickel and copper elements form a copper-rich phase containing Ni, and remain in the outer oxidation layer in solid state, reduce the enrichment of copper in the matrix, reduce the opportunity of liquid copper-rich phase formation, thereby avoiding the occurrence of hot brittle defect; but too high nickel will increase the adhesion of the oxide scale, and the pressure into the steel will form hot rolling defects on the surface, and nickel is a precious metal, and too high content will significantly increase the alloy cost of the steel material; therefore, the value range of Ni in the present application is set to 0.12-0.20%.

[0025] Copper: copper is added to the steel, which is beneficial to form a dense and well-adhesive amorphous oxide protective layer on the surface of the steel, and the corrosion resistance is obvious; in addition, copper and sulfur form a hardly soluble sulfide, thereby reducing the harmful effect of S on the corrosion resistance of the steel; however, when the copper content is too high, due to the low melting point of copper, which is lower than the heating temperature of the billet, the separated copper is in liquid state and gathered at the austenite grain boundary, when the separated copper content reaches a certain degree, cracks are easily produced during heating or hot rolling, that is, "copper brittle" defect; in addition, according to the calculation formula of atmospheric corrosion resistance index I, too small or too large copper content will reduce the calculated value of I. Therefore, the value range of Cu in the present application is set to 0.25-0.35%.

[0026] Niobium: niobium can pin the austenite grain boundary to prevent grain growth, finally refining the grain, which is beneficial to improve the strength and plasticity; however, niobium is a precious metal, and too high content will significantly increase the production cost; therefore, the value range of Nb in the present application is set to 0.035-0.045%.

[0027] Titanium: titanium can form tiny carbonitride to pin the grain boundary, delay recrystallization, inhibit austenite grain growth, produce fine-grain strengthening and precipitation strengthening effect; at the same time, the carbonitride of titanium can provide nucleation core for the precipitation of niobium element during rolling process, thereby promoting the precipitation and further improving the fine-grain effect; however, too high titanium content is easy to form large-size TiN, which leads to the reduction of bending performance and forming performance; therefore, the value range of Ti in the present application is set to 0.010-0.020%. The strength of the steel in the present application is relatively low, therefore, the added titanium content is less, which is not easy to combine with N element to form large-size TiN leading to performance reduction, and in the case of not limiting the N content, the N content in the molten steel can be generally controlled at a low level, so the present application does not limit N.

[0028] Aluminum: aluminum is added to the steel to play the role of deoxidization, which can improve the steel quality, but too high aluminum content is easy to cause the nitride to precipitate at the austenite grain boundary, leading to the production of billet cracks. Therefore, the value range of Als in the present application is set to 0.010-0.045%.

[0029] The application further discloses a preparation method of the hot-rolled weathering steel plate for highway guardrails.

[0030] Further to the heating step, the slab is heated in a regenerative heating furnace, and the slab is heated to homogenize the as-cast structure and composition segregation and to solid-solve alloying elements. The hot-rolled weathering steel plate for highway guardrails has many types of alloying elements and high contents of the alloying elements, and therefore, sufficient temperature and time are required in the heating process. However, excessively high heating temperature and excessively long heating time can result in coarse austenite grains and problems such as burning, overheating and overburning. Therefore, in the heating step, the heating temperature is set to 1200-1240 DEG C, and the heating time is set to 150-250 min.

[0031] Further to the rough rolling step, if the intermediate slab thickness is too small, the deformation amount in the finish rolling can be insufficient; if the intermediate slab thickness is too large, the deformation amount in the rough rolling can be insufficient, and the critical deformation amount for austenite recrystallization cannot be reached, so that austenite grains cannot be refined and mixed grain structure cannot be prevented. Therefore, in the rough rolling step, the slab is rough-rolled for 5 passes, the deformation amount in each pass is greater than or equal to 18%, and the intermediate slab thickness is 35-39 mm. In addition, in order to inhibit austenite grain coarsening of the intermediate slab and achieve good phosphorus removal effect to improve the surface quality of the strip, odd pass descaling is adopted, and even pass descaling can be added when the descaling is poor, and the water pressure for descaling in each pass of the rough rolling is greater than or equal to 18 MPa.

[0032] Further to the finish rolling step, if the finish rolling opening temperature is too low, the finish rolling temperature can be too low; if the finish rolling opening temperature is too high, the deformation amount in the austenite unrecrystallized zone in the finish rolling process is insufficient, which is not conducive to structure refinement; if the finish rolling temperature is too low, there is a risk that several racks after the finish rolling are rolled in the two-phase zone, which results in mixed grain structure and poor product comprehensive performance; and if the finish rolling temperature is too high, the deformation amount in the austenite unrecrystallized zone is insufficient, which is not conducive to final structure refinement. Therefore, in the finish rolling step, the slab is finish-rolled for 7 passes, the opening temperature is 1050-1110 DEG C, and the finish rolling temperature is 860-900 DEG C.

[0033] Further to the laminar cooling step, a large supercooling degree can be achieved by using the front section cooling mode to refine the final structure, and a large cooling speed can improve the center banded structure and increase the precipitation driving force of Ti element, thereby precipitating fine and dispersed second phase particles to enhance the precipitation strengthening effect. Therefore, the front section cooling mode is used in the present application, which means that when the strip enters the laminar cooling section after finishing rolling, the upper and lower surfaces of the strip are water-cooled by spraying water through the upper and lower headers at the start position of the laminar cooling section. The strip is water-cooled to 680-720℃ at a cooling speed of 60-90℃ / s, and then air-cooled to the coiling temperature.

[0034] Further to the coiling step, if the coiling temperature is too low, the cooling speed during the cooling process will be too large, resulting in the generation of low-temperature structures such as martensite, which reduces the plasticity. At the same time, the diffusion speed of Ti and C elements will be slowed down, resulting in blocked precipitation and reduced precipitation strengthening effect. If the coiling temperature is too high, the grains and second phase particles will be coarse, resulting in reduced strength and plasticity. Therefore, the coiling temperature is set to 630-670℃ in the present application.

[0035] The inventors have obtained steels with different strengths by reasonably controlling the composition and designing the heating temperature, cooling temperature and coiling temperature, thereby achieving the regulation of the strength of the product and the energy consumption of the single section guardrail, so as to meet the different performance requirements and lightweight application demands of the highway guardrail steel plate in actual application, such as higher strength or higher energy consumption of the single section guardrail. More specifically, the inventors have obtained a high-strength hot-rolled weathering steel plate for highway guardrails and the hot-rolled weathering steel plate for highway guardrails of the present application.

[0036] By reasonably and appropriately reducing the content of strengthening elements (Mn, Nb, Ti) and combining with the optimization of the process, although the strength of the steel of the present application is relatively low, the elongation after fracture is higher, and the thickness is larger, so that the high energy consumption of the single section guardrail comparable to the high-strength hot-rolled weathering steel plate can be achieved.

[0037] The present application will be further described in detail by the following examples, but the scope of protection of the present application is not limited in the range of the examples.

[0038] In the present application, the corrosion resistance index I of the hot-rolled weathering steel plate for highway guardrails is I=26.01(%Cu)+3.88(%Ni)+1.20(%Cr)+1.49(%Si)+17.28(%P)-7.29(%Cu)(%Ni)-9.10(%Ni)(%P)-33.39(%Cu) 2 .

[0039] In the embodiment, the yield strength, tensile strength and elongation after fracture of the hot-rolled weathering steel plate for highway guardrails are tested according to "Metallic materials, tensile testing - Part 1: Test method at room temperature" (GB / T 228.1); the bending performance is tested according to "Metallic materials, bending test method" (GB / T 232).

[0040] The energy dissipation capacity of a guardrail mainly originates from the plastic deformation of the steel during a collision. The key stage of energy absorption is the stable plastic flow process from the yield point to the necking point. Therefore, based on the principle of safe design, conservative calculations are performed. The average stress during the stable plastic flow process under external force is calculated based on the material's yield strength and tensile strength. The product of the average stress and the elongation after fracture is defined as the plastic energy dissipation rate. Then, based on the material thickness (2.5–4.0 mm) and the standard dimensions of a highway guardrail (480 mm unfolded width, 4000 mm single section length), the plastic deformation volume of a single section of the highway guardrail is calculated. Finally, the product of the plastic energy dissipation rate and the plastic deformation volume of a single section of the highway guardrail is the plastic energy dissipation of a single section of the guardrail. The specific calculation formula is as follows: E=(σ s +σ b ) / 2×δ h ×(l×w×t;Where, E: Plastic energy dissipation of a single guardrail section (J); σ s σ b : These represent the yield strength and tensile strength (MPa) of the material, respectively; δ h : Elongation at break of the material; l, w, t: length, width, and thickness (cm) of the highway guardrail, respectively.

[0041] Example 1 The chemical composition of the hot-rolled weathering steel plate used for highway guardrails in this embodiment is shown in Table 1. The balance is Fe and unavoidable impurities, and the corrosion resistance index I reaches 5.8.

[0042] This embodiment describes the preparation method of hot-rolled weathering steel plates for highway guardrails. The plates are smelted into slabs using conventional methods according to their composition. The slabs are then further processed through heating, rough rolling, finish rolling, laminar flow cooling, and coiling. The specific processing steps are as follows: heating temperature is 1220℃, heating time is 196 min; after 5 passes of rough rolling, the deformation amounts for each pass are 18%, 28%, 31%, 33%, and 32%, respectively, with an intermediate slab thickness of 37 mm; descaling is performed using extra passes, with a descaling water pressure ≥18 MPa for each pass; after 7 passes of finish rolling, the initial rolling temperature is 1060–1090℃, and the final rolling temperature is 870–900℃; a front-stage cooling mode is used, with water cooling at a rate of 85℃ / s to 690–710℃; the coiling temperature is 640–660℃.

[0043] The specific properties of the hot-rolled weathering steel plate for highway guardrails in this embodiment are shown in Table 2; the metallographic structure is composed of polygonal ferrite + a small amount of pearlite + a small amount of cementite, as shown in Figure 1 .

[0044] Example 2 The chemical composition of the hot-rolled weathering steel plate for highway guardrails in this embodiment is shown in Table 1, and the balance is Fe and unavoidable impurities, and the corrosion resistance index I reaches 5.9.

[0045] The preparation method of the hot-rolled weathering steel plate for highway guardrails in this embodiment is as follows: the slab is smelted according to the composition by a conventional method, and the smelted slab is further processed, and heating, rough rolling, finish rolling, laminar cooling and coiling are sequentially performed, and the specific processing process is as follows: the heating temperature is 1230℃, and the heating time is 210min; after 5 passes of rough rolling, the deformation amount of each pass is 18%, 30%, 30%, 32% and 32% respectively, the intermediate blank thickness is 37mm, and the odd pass is used for descaling, and the water pressure of each pass is ≥18MPa; after 7 passes of finish rolling, the opening rolling temperature is 1050-1080℃, and the final rolling temperature is 860-890℃; the front cooling mode is used, and the water cooling speed is 70℃ / s to 680-700℃, and the coiling temperature is 630-650℃.

[0046] The specific properties of the hot-rolled weathering steel plate for highway guardrails in this embodiment are shown in Table 2; the metallographic structure is composed of polygonal ferrite + a small amount of pearlite + a small amount of cementite, as shown in Figure 2 .

[0047] Table 1 Chemical composition of the embodiment / wt% Table 2 Performance test results of the embodiment According to the preparation method of the embodiment, and the chemical composition in Table 1 and the performance test results in Table 2, it can be seen that the hot-rolled weathering steel plate for highway guardrails produced according to the alloy composition and key process parameters provided by the present application not only has good corrosion resistance, but also has high strength and high plasticity, thereby realizing high energy consumption of single section guardrail, taking a small car as an example, the weight thereof is about 1248kg, and the kinetic energy reaches 6.93×10 5 J when the speed is 120km / h, and the energy consumption of the single section guardrail made of the embodiment is much higher than the value, thereby having excellent safety, and avoiding the use of parallel double-row guardrails, thereby realizing lightweight application, so that the hot-rolled weathering steel plate for highway guardrails has good comprehensive performance and application prospect.

Claims

1.A method for preparing a hot-rolled weathering steel plate for highway guardrails, characterized in that: the hot-rolled weathering steel plate for highway guardrails has the following composition by weight percentage: C 0.05-0.07%, Si 0.25-0.35%, Mn 1.10-1.20%, P≤0.020%, S≤0.007%, Cr 0.40-0.50%, Ni 0.12-0.20%, Cu 0.25-0.35%, Nb 0.035-0.045%, Ti 0.010-0.020%, Al 0.010-0.045%, and the balance of Fe and inevitable impurities; the method comprises the following steps: smelting, heating, rough rolling, finish rolling, laminar cooling, and coiling to obtain the hot-rolled weathering steel plate for highway guardrails; wherein, in the heating step, the heating temperature is 1200-1240℃, and the heating time is 150-250 min; in the rough rolling step, the strip is rolled through 5 passes, each pass has a deformation of≥18%, and the intermediate blank has a thickness of 35-39 mm; the scale is removed in the odd passes, and the scale removal water pressure is≥18 MPa; in the finish rolling step, the strip is rolled through 7 passes, the opening rolling temperature is 1050-1110℃, and the final rolling temperature is 860-900℃; in the coiling step, the coiling temperature is 630-670℃; the hot-rolled weathering steel plate for highway guardrails has a thickness of 2.5-4.0 mm; in the laminar cooling step, the strip is cooled to 680-720℃ at a cooling rate of 60-90℃ / s, and then air-cooled to the coiling temperature; in the rough rolling step, additional scale removal is performed in the even passes when the scale removal is poor; the hot-rolled weathering steel plate for highway guardrails has an atmospheric corrosion resistance index I of 5.5-6.7; the yield strength is≥500 MPa, the tensile strength is≥600 MPa, the elongation after fracture is≥30%, and the 180° bending test result is D=a. 8.The hot-rolled weathering steel plate for highway guardrails prepared by the method of any one of claims 1-7. ​ ​ ​ ​ ​ 2. The method of producing a hot-rolled weathering steel plate for a highway guardrail according to claim 1, characterized by: ​ 3. The method of producing a hot-rolled weathering steel plate for a highway guardrail according to claim 1, characterized by: ​ 4. The method of producing a hot-rolled weathering steel plate for a highway guard bar according to claim 1, characterized by: ​ 5. The method of producing a hot-rolled weathering steel plate for a highway guardrail according to claim 1, characterized in that: ​ 6. The method of producing a hot-rolled weathering steel plate for a highway guard bar according to claim 1, characterized in that: ​ 7. Process for the production of hot-rolled weathering steel sheets for highway guard rails according to any one of claims 1 to 6, characterized in that: The single-section guardrail made of the high-strength hot-rolled weather-resistant steel plate for highway guardrails has energy consumption ≥7.92×10 5 J. ​

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