Rapid evaluation method for atmospheric corrosion resistance of weathering resistant steel and application of rapid evaluation method

Abstract

The invention discloses a rapid evaluation method for atmospheric corrosion resistance of weathering resistant steel and application thereof, the evaluation method comprises the following steps: S1, calculating an atmospheric corrosion resistance index I of the weathering resistant steel based on chemical components of the weathering resistant steel according to the following formula: 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, and if I is greater than or equal to 6.2, entering subsequent test evaluation; s2, performing a neutral salt spray test on the sample meeting the step S1 for 72 hours, then calculating the salt spray corrosion rate, and if the salt spray corrosion rate is less than or equal to 1.16 g / (m < 2 >. H), judging that the sample is qualified; s3, if the weathering resistant steel is used in the high-humidity atmospheric environment, a periodic infiltration test needs to be carried out, and if the periodic infiltration corrosion rate is smaller than or equal to 1.958 g / (m < 2 >. H), it is judged that the weathering resistant steel is applicable; and S4, if the weathering resistant steel is used for a typical atmospheric environment with high temperature, high humidity and serious corrosion, an atmospheric exposure test needs to be performed for 12 months, and if the stable corrosion rate is smaller than or equal to 0.031 g / (m < 2 >. H), it is judged that the weathering resistant steel is applicable. The weather-resistant steel corrosion performance evaluation system is established by analyzing the atmospheric corrosion resistance index of the weather-resistant steel and the corrosion results of different materials in different typical environments.

Description

Technical Field

[0001] This invention belongs to the field of metallic material evaluation, and in particular relates to a rapid evaluation method for the atmospheric corrosion resistance of weathering steel and its application. Background Technology

[0002] Weathering steel, also known as atmospheric corrosion resistant steel, is a type of low-alloy structural steel with excellent corrosion resistance in natural atmospheric environments. Compared to ordinary carbon structural steel, weathering steel, through the addition of small amounts of alloying elements such as copper, chromium, nickel, and phosphorus, forms a dense, stable, and self-healing protective rust layer (commonly referred to as a "stabilized rust layer") on its surface, significantly inhibiting further erosion of the base metal by corrosive media (such as moisture, oxygen, and sulfur dioxide). Studies have shown that the atmospheric corrosion resistance of weathering steel can be 2 to 8 times that of ordinary carbon steel, and its corrosion resistance becomes more significant with extended service life.

[0003] In addition to its excellent weather resistance, weathering steel also possesses good mechanical properties, weldability, and cold and hot working properties, allowing it to serve for extended periods without painting or requiring only simple protection, significantly reducing total life-cycle maintenance costs. Therefore, weathering steel is widely used in various engineering fields, including railway vehicles, bridges, high-rise buildings, containers, power transmission and communication towers, construction machinery, automobiles, agricultural machinery, ships, boilers and pressure vessels, pipeline systems, road guardrails, and urban sanitation facilities.

[0004] However, the actual corrosion behavior of weathering steel is significantly affected by factors such as humidity, temperature, and pollutant (such as Cl- and SO2) concentrations in the service environment (e.g., industrial atmosphere, marine atmosphere, rural atmosphere). Corrosion rates and rust evolution mechanisms vary considerably across different regions and climatic conditions. Currently, the evaluation of the corrosion resistance of weathering steel in engineering practice largely relies on long-term outdoor exposure tests, which are time-consuming, costly, and data-lagging, failing to meet the urgent needs for rapid screening of new materials and selection of engineering materials. Although some laboratory accelerated corrosion testing methods (such as salt spray tests, damp heat cycling, and SO2 corrosion tests) have been used to simulate atmospheric corrosion processes, their correlation with the actual atmospheric environment remains unclear, and a systematic, unified, and quantifiable corrosion resistance evaluation process is lacking.

[0005] Therefore, there is an urgent need to develop a rapid evaluation method for the corrosion performance of weathering steel under typical atmospheric conditions. Summary of the Invention

[0006] In view of this, the present invention provides a rapid evaluation method for the atmospheric corrosion resistance of weathering steel. This method analyzes the atmospheric corrosion resistance index of weathering steel and the corrosion results of different materials in different typical environments, obtains the basic laws of atmospheric corrosion resistance of weathering steel, and establishes an evaluation system for the corrosion performance of weathering steel.

[0007] This invention provides a method for evaluating the atmospheric corrosion resistance of weathering steel, comprising the following steps:

[0008] S1. Calculate the atmospheric corrosion resistance index I based on the chemical composition of weathering steel. The index I is calculated according to the following formula: I = 26.01Cu + 3.88Ni + 1.20Cr + 1.49Si + 17.28P - 7.29Cu×Ni - 9.10Ni×P - 33.39(Cu) 2 Where Cu, Ni, Cr, Si, and P are the mass percentages of the corresponding elements in the steel; if I ≥ 6.2, then proceed to subsequent experimental evaluation;

[0009] S2. Conduct a neutral salt spray test on the samples that meet the requirements of step S1 for 72 hours, and then calculate the salt spray corrosion rate. If the salt spray corrosion rate is ≤1.16 g / (m²), the corrosion rate is determined. 2 If the result is ·h), then it is considered qualified;

[0010] S3. If weathering steel is used in a high-humidity atmospheric environment, a periodic immersion test is also required to calculate the periodic immersion corrosion rate. If the periodic immersion corrosion rate is ≤1.958g / (m 2 If ·h), then it is determined to be applicable;

[0011] S4. If used in typical atmospheric environments with high temperature, high humidity, and severe corrosion, a 12-month atmospheric exposure test is also required, with a stable corrosion rate ≤0.031 g / (m³). 2 If ·h), then it is determined to be applicable.

[0012] Preferably, the specific steps of the neutral salt spray test are as follows: a 50 g / L sodium chloride aqueous solution is used, and the test is conducted at 25°C. One side of the sample is exposed, and the non-exposed side is protected. After the test, a 1:1 hydrochloric acid solution containing 3.5 g / L hexamethylenetetramine is used to remove the corrosion products, and the sample is accurately weighed. Then, the corrosion rate is calculated.

[0013] Preferably, the sample used in the neutral salt spray test is prepared by cutting it into 50×50×5mm samples using wire cutting and then grinding it to achieve a surface accuracy Ra of 0.7μm.

[0014] Preferably, the sample is punched and marked before testing, then cleaned with acetone and alcohol and weighed, with the mass accurate to 0.0001g.

[0015] Preferably, the specific method of the cyclic immersion test is as follows: it is carried out in a DW-UD-3 type immersion dry-wet composite cycle tester, each cycle is 60 minutes, each cycle is first immersed at 40°C for 6 minutes, wetted for 6 minutes, and then dried at 50°C for 48 minutes, for a total of 72 cycles.

[0016] Preferably, the method for preparing the specimens used in the periodic immersion test is as follows: using wire cutting to cut specimens with dimensions of 100mm×50mm×2mm, and grinding to achieve a surface roughness Ra≤0.7μm.

[0017] Preferably, the method further includes characterizing the morphology and thickness of the rust layer of the corroded sample: a scanning electron microscope is used to observe a 10mm×10mm surface sample and a 10mm×10mm×3mm cross-sectional sample, wherein the cross-sectional sample is hot-mounted, gradually ground to 2000 grit sandpaper, polished and gold-sprayed before observation.

[0018] Preferably, the atmospheric exposure test is conducted according to GB / T6464-1997. The test specimens are 50mm×50mm×3mm in size and are exposed at a typical atmospheric environment site for 12 months. The corrosion rate during the stable phase is used as the evaluation criterion.

[0019] Preferably, the "high humidity atmospheric environment" refers to coastal or subtropical areas with an annual average relative humidity of ≥70%; the "high temperature, high humidity and severely corrosive atmospheric environment" refers to areas with an annual average temperature of ≥20℃, relative humidity of ≥80%, and containing salt or industrial pollutants.

[0020] This invention also provides the application of the above-mentioned rapid evaluation method for the atmospheric corrosion resistance of weathering steel. The method is applied to the rapid screening of the corrosion resistance of weathering steel used in power transmission towers, bridges, building steel structures, containers, engineering machinery and road guardrails.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention provides a rapid evaluation method for the atmospheric corrosion resistance of weathering steel. By studying the corrosion behavior of new weathering steel under different typical atmospheric environments and the corrosion behavior under accelerated laboratory tests, and by comparing and analyzing the atmospheric corrosion resistance index of weathering steel with the corrosion results of different materials in different typical environments, the basic laws of atmospheric corrosion resistance of weathering steel are obtained, thereby establishing a method for evaluating the corrosion performance of weathering steel. This method plays an important role in promoting the application of weathering steel in power transmission and transformation projects, and can effectively control the corrosion performance of weathering steel used in power transmission and transformation projects, thus enabling weathering steel structural components to reach their designed service life. Attached Figure Description

[0023] Figure 1 This is a flowchart for evaluating the corrosion performance of weathering steel.

[0024] Figure 2 Macroscopic morphology of different samples in neutral salt spray corrosion test.

[0025] Figure 3 This graph shows the relationship between atmospheric exposure time and corrosion rate in different regions.

[0026] Figure 4 Macroscopic morphology of samples exposed to atmospheric corrosion for one month in different regions.

[0027] Figure 5 Macroscopic morphology of samples exposed to atmospheric corrosion for three months in different regions.

[0028] Figure 6 Macroscopic morphology of samples exposed to atmospheric corrosion for six months in different regions.

[0029] Figure 7 Macroscopic morphology of samples exposed to atmospheric corrosion in different regions for twelve months. Detailed Implementation

[0030] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0031] Example 1

[0032] like Figure 1 As shown in the figure, this embodiment provides a method for evaluating the atmospheric corrosion resistance of weathering steel, including the following steps:

[0033] S1. Calculate the atmospheric corrosion resistance index I based on the chemical composition of weathering steel. The index I is calculated according to the following formula: I = 26.01Cu + 3.88Ni + 1.20Cr + 1.49Si + 17.28P - 7.29Cu×Ni - 9.10Ni×P - 33.39(Cu) 2 Where Cu, Ni, Cr, Si, and P are the mass percentages of the corresponding elements in the steel; if I ≥ 6.2, then proceed to subsequent experimental evaluation.

[0034] S2. Conduct a neutral salt spray test on the samples that meet the requirements of step S1 for 72 hours, and then calculate the salt spray corrosion rate. If the salt spray corrosion rate is ≤1.16 g / (m²), the corrosion rate is determined. 2 If the result is ·h), then it is considered qualified;

[0035] Specifically, the samples were cut into 50×50×5mm pieces using wire cutting and then machined to a surface finish Ra of 0.7μm. Before testing, the samples were punched and marked, then cleaned with acetone and alcohol and weighed to an accuracy of 0.0001g.

[0036] The neutral salt spray corrosion test of the samples was conducted in a TC-J-1 type salt spray corrosion test chamber. The test solution was a 50 g / L sodium chloride distilled aqueous solution, and the neutral salt spray test (NSS test) method was used for 72 hours at a temperature of 25℃. The samples were subjected to single-sided corrosion, with the non-corroded side protected. After corrosion, the samples were immersed in a 1:1 (volume ratio) hydrochloric acid solution with 3.5 g / L hexamethylenetetramine corrosion inhibitor to remove corrosion products, and then dried and weighed. The corrosion rate was calculated according to the formula... Calculation, where W is the atmospheric corrosion rate, g / (m²). 2 .h); G0 and G1 are the original mass and the mass after corrosion and rust removal of the sample, respectively, in g; a and b are the length and width of the sample, respectively, in mm; t is the test time, in h.

[0037] S3. If weathering steel is used in a high-humidity atmospheric environment, a periodic immersion test is also required to calculate the periodic immersion corrosion rate. If the periodic immersion corrosion rate is ≤1.958g / (m 2 If ·h), then it is determined to be applicable;

[0038] Specifically, 100mm×50mm×2mm samples were cut using wire cutting, and the surface accuracy Ra was achieved to 0.7μm after grinding. Before the test, holes were drilled and marked, and then the samples were cleaned with acetone and alcohol and weighed with a mass accurate to 0.0001g.

[0039] The cyclic immersion test of the samples was conducted in a DW-UD-3 type immersion-wet composite cyclic testing machine. The immersion solution was 0.01 mol / L NaHSO3, and each cycle was 60 min, consisting of immersion at 40℃ for 6 min, wetting for 6 min, and drying at 50℃ for 48 min. The samples underwent accelerated corrosion for 72 cycles. After corrosion, the weight loss rate was calculated according to TB / T2883. Five parallel samples were taken from each group, and the average value was used. Corrosion rate determination: Rust removal from the cyclic immersion test samples was performed according to standard GB / T16545-2015 "Corrosion of Metals and Alloys - Removal of Corrosion Products from Corrosion Specimens". An analytical balance with an accuracy of 0.0001 was used to measure the rust removal rate of the samples. The cyclic immersion corrosion rate was determined according to the formula... Calculations are performed. In the formula, W represents the atmospheric corrosion rate, in g / (m³). 2 h); G0 and G1 are the original mass and the mass after corrosion and rust removal of the sample, respectively, in g; a, b, and c are the length, width, and thickness of the sample, respectively, in mm; t is the test time, in h.

[0040] S4. If weathering steel is used in a typical atmospheric environment with high temperature, high humidity, and severe corrosion, a 12-month atmospheric exposure test is required, and the corrosion rate must be calculated. The corrosion rate at the steady-state stage should then be used as the evaluation criterion. If the steady-state corrosion rate is ≤0.031 g / (m³), the corrosion rate is considered stable.2 If ·h), then it is determined to be applicable.

[0041] Specifically, the samples were prepared according to standard GB / T6464-1997, with sample dimensions of 50mm×50mm×3mm, and rust layer analysis samples with dimensions of 10mm×10mm×3mm. The atmospheric exposure test was designed with four test cycles: 1 month, 3 months, 6 months, and 12 months.

[0042] S5. The morphology and thickness of the rust layer of the samples after corrosion by S2, S3 and S4 were characterized: The 10mm×10mm surface sample and the 10mm×10mm×3mm cross-sectional sample were observed by scanning electron microscopy. The cross-sectional sample was hot-mounted, ground step by step to 2000 grit sandpaper, polished and gold-sprayed before observation.

[0043] Example 2 This example examines the atmospheric corrosion resistance index (I) of weathering steel.

[0044] In this embodiment, the weathering steel is S-345NH steel plate, and the mass percentage of the corresponding elements in the steel is shown in Table 1 below:

[0045] Table 1. Chemical and gas analysis of elemental content (mass fraction, %) in S-345NH steel

[0046] element C Mn Ni Si Nb Al content 0.072 1.32 0.21 0.39 0.013 0.037 element Cr S P Cu O N content 0.40 0.002 0.016 0.26 0.0010 0.0058

[0047] The I value calculated using step S1 of Example 1 is 6.75, which is greater than 6.2, thus the atmospheric corrosion resistance index I of S-345NH steel plate is qualified.

[0048] Example 2 investigated the corrosion rate of two different materials under neutral salt spray.

[0049] In this embodiment, 345J2W weathering steel and Q235 steel plate were selected. Neutral salt spray test was carried out according to the method of step S2 in Example 1, and the neutral salt spray corrosion rate of 345J2W weathering steel and Q235 steel plate was calculated and recorded in Table 2 below.

[0050] Table 2 Corrosion rates from neutral salt spray corrosion tests

[0051] Sample Name time <![CDATA[Corrosion rate g / m 2 .h]]> S-345NH 72h <![CDATA[1.16g / m 2 .h]]> Q235 72h <![CDATA[1.74g / m 2 .h]]>

[0052] Table 3 shows that the corrosion rate of S-345J2W weathering steel is 1.16 g / m. 2 The corrosion rate of Q235 steel plate is 1.74 g / m. 2 The corrosion rate of .h is 1.5 times that of weathering steel.

[0053] Then, the surface and cross-section of the rust layer were observed according to step S4 in Example 1. After the neutral salt spray corrosion test, the macroscopic morphology of the corrosion samples of the two materials differed significantly. Figure 4 (S-345NH is on the left, Q235 is on the right). From Figure 4 As can be seen, after corrosion, the rust layer of the S-345NH sample adheres to the substrate surface, has a certain depth, and is complete and dense. The rust layer of the Q235 sample is incomplete after corrosion; as corrosion deepens, the rust layer gradually falls off, only to be followed by further corrosion, thus creating a cycle. Some localized rust spots remain, providing some protection to the substrate.

[0054] Example 3 examines the corrosion rate of two different materials under cyclic immersion.

[0055] In this embodiment, S-345NH and Q235 steel plates were selected and subjected to cyclic immersion tests according to the method in step S3 of Example 1. The cyclic immersion corrosion rates of S-345NH and Q235 steel plates were calculated and recorded in Table 3 below.

[0056] Table 3 Comparison of Cyclic Immersion Corrosion Results between S-345NH and Q235 Steel Plates

[0057] Corrosion methods Time / h <![CDATA[S-345NH corrosion rate g / m 2 .h]]> <![CDATA[Corrosion rate of Q235 g / m 2 .h]]> Cyclic immersion corrosion 75 <![CDATA[1.958g / (m 2 ·h)]]> <![CDATA[3.805g / (m 2 ·h)]]>

[0058] As shown in Table 3, the cyclic wetting corrosion rate of S-345NH is 1.958 g / (m²). 2 The corrosion weight loss rate of S-345NH is only half that of Q235 steel, indicating that S-345NH has high atmospheric corrosion resistance.

[0059] Example 4 This example investigates the effects of exposure to different atmospheric conditions on the corrosion of S-345NH steel plates.

[0060] In this embodiment, atmospheric exposure experiments were conducted under different atmospheric conditions (Dalian, Liangxiang, Wuhan, and Pingtan). S-345NH weathering steel samples were prepared according to standard GB / T 6464-1997, with sample dimensions of 50mm × 50mm × 3mm. Rust layer analysis samples were 10mm × 10mm × 3mm in size. The atmospheric exposure test was designed with four test periods: 1 month, 3 months, 6 months, and 12 months.

[0061] The changes in corrosion rate of samples from different regions over different time periods are shown in the figure. Figure 2 It can be seen that as the exposure time increases, the corrosion rate gradually decreases, eventually stabilizing at 0.02–0.04 g / (m²). 2 Between ·h).

[0062] Corrosion samples exposed to different atmospheres were observed on the surface and cross-section of the rust layer using a HITACHI S-3400N scanning electron microscope. The macroscopic morphology varied, and the macroscopic morphology of the samples after different corrosion times at various sites is shown in the figure. Figure 4-7 ,in, Figure 4-7 From left to right, the locations are Dalian, Liangxiang, Wuhan, and Pingtan.

[0063] The relationship between the rust depth of the corroded section and the corrosion time is shown in Table 4 below.

[0064] Table 4 Corrosion Time and Rust Depth

[0065]

[0066]

[0067] Combination Figure 4-7 As shown in Table 4, after one month of corrosion, the rust layer of the Zhuanghe sample was shallow and discontinuously distributed; after three months, it became continuously distributed, and the rust layer depth gradually increased with the extension of corrosion time. The rust layer of the Liangxiang sample remained continuously distributed and narrow, with its depth gradually increasing over time. The rust layer of the Wuhan sample was continuously distributed, reaching a depth of 40-50 μm after one month of corrosion, and then gradually increasing. The rust layer of the Pingtan sample was continuously distributed, reaching a depth of 40-50 μm after one month of corrosion; after six months, the depth in some areas exceeded 100 μm; and after twelve months, the depth in some areas exceeded 130 μm. Therefore, it can be concluded that the rust layer depth basically follows the same pattern as the corrosion rate.

[0068] Example 5 This example examines the effect of different conditions on the corrosion rate of S-345NH.

[0069] In this embodiment, the corrosion rate of S-345NH was determined by laboratory accelerated testing according to steps S2-S4 in Example 1. Atmospheric exposure tests were conducted for 12 months under different atmospheric conditions (Dalian, Beijing, Wuhan, Fujian) to calculate the atmospheric corrosion rate. The stable value of the atmospheric corrosion rate over 12 months was then used, and the data are recorded in Table 5 below.

[0070] Table 5 Corrosion rates of S-345NH weathering steel under different conditions

[0071]

[0072] As can be seen from the data in Table 5, the corrosion rate in the accelerated laboratory test is nearly 100 times different from the corrosion rate in the actual atmospheric environment. Therefore, the accelerated laboratory test can be used to judge the atmospheric corrosion resistance of weathering steel.

[0073] Based on the above embodiments and the combined results of cyclic immersion corrosion and neutral salt spray tests, it can be seen that the present invention can establish a corrosion performance evaluation process for weathering steel and related index requirements as follows: corrosion resistance index I ≥ 6.2 and the corrosion rate of the sample under test in the neutral salt spray corrosion test must be lower than 1.16 g / m³. 2 • h; If it is a high-humidity atmospheric environment, a perimeter immersion corrosion evaluation is required, and the corrosion rate of the sample to be tested must be lower than 1.958 g / m. 2 •h; If the sample is in a high-temperature, high-humidity, and severely corrosive atmospheric environment, an atmospheric exposure test is required, and the corrosion rate of the sample must be less than 0.031 g / (m²). 2 ·h).

[0074] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A method for rapidly evaluating the atmospheric corrosion resistance of a weathering steel, characterized in that, The method comprises the following steps: S1, calculate the atmospheric corrosion resistance index I of the weathering steel based on its chemical composition, the index I is calculated according to the following formula: I = 26.01Cu + 3.88Ni + 1.20Cr + 1.49Si + 17.28P - 7.29Cu x Ni - 9.10Ni x P - 33.39(Cu) 2 Wherein, Cu, Ni, Cr, Si, P are the mass percentage content of corresponding elements in the steel; if I≥6.2, enter the subsequent test evaluation; S2, performing a neutral salt spray test on the sample satisfying step S1, and then calculating a salt spray corrosion rate, wherein if the salt spray corrosion rate is ≤1.16 g / (m 2 ·h), it is determined to be qualified; S3, if the weathering steel is used in high humidity atmosphere, a periodic immersion test is also needed, the periodic immersion corrosion rate is calculated, if the periodic immersion corrosion rate is ≤1.958g / (m 2 ·h), it is determined to be applicable; S4, if the weathering steel is used in a typical atmospheric environment with high temperature, high humidity and severe corrosion, a 12-month atmospheric exposure test is also required. If the stable corrosion rate is ≤0.031 g / (m 2 ·h), it is determined to be applicable.

2. The method for rapidly evaluating the atmospheric corrosion resistance of a weathering steel according to claim 1, characterized by, The specific steps of the neutral salt spray test are as follows: 50g / L sodium chloride aqueous solution is used, the test is carried out at 25℃, the sample is exposed on one side, the non-exposed side is protected, after the test, the corrosion product is removed by using 1:1 hydrochloric acid solution containing 3.5g / L hexamethylenetetramine, and the sample is accurately weighed, and then the corrosion rate is calculated.

3. The method for rapidly evaluating the atmospheric corrosion resistance of a weathering steel according to claim 1 or 2, characterized in that, The sample used in the neutral salt spray test is prepared by using wire cutting to cut a sample with a size of 50*50*5mm, and the surface precision Ra of the sample is processed to 0.7μm by a grinding machine.

4. The method for rapidly evaluating the atmospheric corrosion resistance of a weathering steel according to claim 3, characterized by, The sample is punched and numbered before the test, then washed by acetone and alcohol, and weighed, and the mass is accurate to 0.0001g.

5. The method for rapidly evaluating the atmospheric corrosion resistance of the weathering steel according to claim 1, characterized by, The sample used in the periodic immersion test is prepared by using wire cutting to cut a sample with a size of 100mm*50mm*2mm, and the surface roughness Ra of the sample is processed to be less than or equal to 0.7μm by a grinding machine.

6. The method for rapidly evaluating the atmospheric corrosion resistance of a weathering steel according to claim 5, characterized by, The specific method of the periodic immersion test is as follows: the test is carried out in a DW-UD-3 type immersion dry-wet combined cycle test machine, each cycle period is 60 minutes, and each cycle period is immersion at 40℃ for 6 minutes, humidification for 6 minutes, and drying at 50℃ for 48 minutes, and a total of 72 cycle periods are carried out.

7. The method for rapidly evaluating the atmospheric corrosion resistance of the weathering steel according to claim 1, characterized by, S5, the rust layer morphology and thickness of the sample corroded in steps S2, S3 and S4 are characterized: 10mm*10mm surface samples and 10mm*10mm*3mm cross-section samples are observed by using a scanning electron microscope, wherein the cross-section sample is observed after being hot-embedded, gradually polished to 2000# sandpaper, polished and gold-sprayed.

8. The method for rapidly evaluating the atmospheric corrosion resistance of the weathering steel according to claim 1, characterized by, The atmospheric exposure test is prepared according to GB / T6464-1997, the size of the prepared sample is 50mm*50mm*3mm, the sample is exposed in a typical atmospheric environment station for 12 months, and the corrosion rate in the stable stage is taken as the evaluation basis.

9. The method for rapidly evaluating the atmospheric corrosion resistance of the weathering steel according to claim 1, characterized by, The "high-humidity atmospheric environment" refers to a coastal or subtropical region with an annual average relative humidity of greater than or equal to 70%; and the "high-temperature and high-humidity atmospheric environment with severe corrosion" refers to a region with an annual average temperature of greater than or equal to 20℃, a relative humidity of greater than or equal to 80%, and containing salt or industrial pollutants.

10. Use of a method for the rapid evaluation of the atmospheric corrosion resistance of a weathering steel according to any one of claims 1 to 9, characterized in that, The method is applied to the rapid screening of the corrosion performance of weathering-resistant steel for power transmission towers, bridges, building steel structures, containers, engineering machinery and road guardrails.

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