CN113933232B - Material corrosion acceleration test method for simulating south China sea island reef environment - Google Patents

Abstract

The invention relates to a material corrosion accelerated test method for simulating a south sea island reef environment, which comprises the following steps: circulating the material to be testedThe method comprises the following steps of (1) performing a circular acceleration test, wherein test items in one period of the circular acceleration test are a coral salt coating test, a salt spray test and a solar radiation test in sequence; wherein, the conditions of the salt spray test comprise: the temperature is 45-55 ℃, and the salt spray sedimentation rate is as follows: 1-2 mL/h.80cm ² (ii) a The conditions of the solar radiation test include: irradiance adopts 1110-1130W/m ² Instantaneous extreme value or 5700-5710W/m ² The intensity conversion values are accumulated. The accelerated experiment method can better accord with the atmospheric corrosion characteristics of the south sea island reef of typical equipment materials, and the test result has strong correlation with the actual environment and higher result validity.

Description

Material corrosion accelerated test method for simulating South China Sea island and reef environment

technical field

The invention relates to the technical field of material environment testing, in particular to a material corrosion acceleration test method for simulating the South China Sea island reef environment.

Background technique

The islands and reefs in the South China Sea are located at low latitudes near the equator and belong to the tropical marine climate. The main climate characteristics of the islands and reefs in the South China Sea are: long hours of sunshine, strong radiation, high temperature all year round, abundant rainfall, high humidity, strong wind, and little fog. Part of the equipment structure continues to suffer from "high temperature, high humidity, high salt, strong solar radiation" in the South China Sea and the dry/wet cycle erosion of splashed sea water. The corrosion problem is serious, which greatly affects the life of the equipment structure and the safe use of the equipment.

Because the traditional natural environment test period is too long, and the sensitivity of different structural materials to the environment is not the same, in order to determine the corrosion effect of the natural environment on the equipment structure, it is necessary to establish the equivalent relationship between the natural environment spectrum and the laboratory accelerated environment spectrum, and design the corresponding The accelerated test spectrum can be used to quickly obtain the corrosion damage law of equipment structural materials and protection systems in the island and reef environment of the South China Sea.

Traditional accelerated corrosion tests include: Standard GB/T 25834-2010 Outdoor Atmospheric Accelerated Corrosion Tests for Metals and Alloys Corrosion Iron and Steel. General requirements for accelerated corrosion tests of iron and steel, such as test procedures, requirements, devices, etc.; standard GB/T 20853-2007 Corrosion of metals and alloys specifies the test values of the relevant components of the sodium chloride solution used for accelerated tests, where the test The solution is prepared by dissolving sodium chloride in distilled or deionized water whose conductivity does not exceed 2mS/m at 25°C±2°C. It illustrates the test method for the corrosion resistance of metals in the presence of chloride ions. The traditional accelerated corrosion tests mentioned above are not suitable for the actual environment of the islands and reefs in the South China Sea, and it is difficult to accurately reflect the corrosion situation in the actual environment of the islands and reefs in the South China Sea.

In addition, according to the marine environmental corrosion problems faced by typical equipment, some scholars have compiled a cycle acceleration spectrum such as periodic infiltration, an acceleration spectrum composed of ultraviolet radiation and periodic infiltration based on the typical marine atmospheric environment spectrum. There are also papers that study the performance change law of typical aviation materials in the South China Sea marine environment after different cycle tests, and calculate the accelerated test method for the South China Sea environment with three test combinations of damp heat, light aging and salt spray. However, in the actual application of the above research, the correlation between the acceleration spectrum and the test results of the actual environment of the islands and reefs in the South China Sea is still weak.

Contents of the invention

Based on this, the present invention provides an accelerated material corrosion test method for simulating the environment of islands and reefs in the South China Sea, which conforms to the characteristics of atmospheric corrosion of islands and reefs in the South China Sea for typical equipment materials, and has strong correlation and high validity of results.

The specific technical scheme is as follows:

An accelerated test method for material corrosion simulating the South China Sea island and reef environment, comprising the following steps:

Carry out a cyclic acceleration test on the material to be tested, and the test items in one cycle of the cyclic acceleration test are coral salt coating, salt spray test and solar radiation test in sequence;

Among them, the conditions of the salt spray test include: the temperature is 45°C-55°C, and the salt spray settling rate: 1-2mL/h.80cm ² ;

The conditions of the solar radiation test include: the irradiance adopts the instantaneous extreme value of 1110-1130W/m ² or the cumulative intensity conversion value of 5700-5710W/m ² .

In one embodiment, the conditions of the salt spray test include: a temperature of 50° C., and a salt spray deposition rate of 1˜2 mL/h.80 cm ² .

In one embodiment, the salt spray solution used in the salt spray test is a neutral modified ASTM-D1141 artificial seawater simulated liquid, wherein the mass fraction of Cl ^- is 3%-4%.

In one of the embodiments, the conditions of the solar radiation test include: the instantaneous extreme value of the irradiance is 1120W/m ² or the cumulative intensity conversion value of 5708.16W/m ² .

In one of the embodiments, the conditions of the solar radiation test further include: the temperature is 45°C-50°C.

In one of the embodiments, the temperature used in the solar radiation test is 49°C.

In one of the embodiments, the step of applying coral salt includes:

Mix coral salt powder and artificial seawater simulation liquid to prepare coral salt solution;

The coral salt solution is coated on the surface of the material to be tested.

In one of the embodiments, the coral salt powder has a mesh size of 800 mesh to 1200 mesh.

In one of the embodiments, the mass fraction of the coral salt powder in the coral salt solution is 8%-12%.

In one of the embodiments, the mass fraction of the coral salt powder in the coral salt solution is 10%.

In one embodiment, in one cycle, the duration of the salt spray test is 14-15 hours, and the duration of the solar radiation test is 9 hours-10 hours.

In one of the embodiments, in one cycle, the time for the salt spray test is 14.5 hours, and the time for the solar radiation test is 9.5 hours.

The above-mentioned accelerated test method for simulating the corrosion of materials in the environment of islands and reefs in the South China Sea, considering the test items, test sequence, and test values, etc., has determined an accelerated test plan that can accurately simulate the corrosion of materials in the environment of islands and reefs in the South China Sea, and can effectively ensure that the test The correlation and validity of the accelerated spectrum and the actual South China Sea island and reef environment test can be directly used in the accelerated test of key equipment and structural materials in the South China Sea island and reef environment, and the corrosion situation during the use of materials can be quickly predicted. Provide data support and technical guidance for the corrosion protection design and corrosion life extension work of the use and maintenance units.

Description of drawings

Fig. 1 is an accelerated spectrum pattern of a material corrosion accelerated test method for simulating the South China Sea island and reef environment in an embodiment of the present invention.

detailed description

The material corrosion acceleration test method for simulating the South China Sea island and reef environment of the present invention will be further described in detail below in conjunction with specific examples. The present invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

In the present invention, the technical features described in open form include closed technical solutions consisting of the enumerated features, as well as open technical solutions including the enumerated features.

In the present invention, when referring to a numerical interval, unless otherwise specified, the above numerical interval is considered continuous, and includes the minimum and maximum values of the range, and every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum of the range is included. Furthermore, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein.

The percentage content involved in the present invention, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid phase mixing, and refers to volume percentage for liquid-liquid phase mixing.

The percentage concentration involved in the present invention refers to the final concentration unless otherwise specified. The final concentration refers to the proportion of the added component in the system after the component is added.

The temperature parameters in the present invention, unless otherwise specifically limited, allow either constant temperature treatment or treatment within a certain temperature range. The isothermal treatment allows the temperature to fluctuate within the precision of the instrument control.

The invention provides a material corrosion accelerated test method for simulating the South China Sea island and reef environment, comprising the following steps:

Carry out a cyclic acceleration test on the material to be tested, and the test items in one cycle of the cyclic acceleration test are coral salt coating, salt spray test and solar radiation test in sequence;

Among them, the conditions of the salt spray test include: the temperature is 45°C-55°C, and the salt spray settling rate: 1-2mL/h.80cm ² ;

The conditions of the solar radiation test include: the irradiance adopts the instantaneous extreme value of 1110-1130W/m ² or the cumulative intensity conversion value of 5700-5710W/m ² .

Specifically, the material to be tested is a typical aerospace material. Further, the material to be tested is a surface-treated substrate. The material of the base material includes but not limited to aluminum or aluminum alloy, structural steel stainless steel, composite materials, etc .; the surface treatment method includes but not limited to chemical conductive oxidation treatment and epoxy coating.

In the above material corrosion accelerated test method, according to the characteristics of the South China Sea island and reef environment test of the material to be tested, on the basis of determining the set of test items, the test items are arranged according to the order of the corrosion factors experienced by a large amount of experience in the actual use of the material . Specifically, because the salt spray test will produce corrosion products, the solar radiation test will modify the corrosion products, so the salt spray test is placed before the solar radiation test; because the coating of coral salt is easy to produce salt, moisture accumulation, and corrosion. , so the coral salt coating is placed before the salt spray test. Based on this, the determined test sequence is: coral salt coating→salt spray test→solar radiation test, and so on. At the same time, it was found that the key parameters affecting the test results in the salt spray test are temperature and salt spray sedimentation rate, and the key parameters affecting the test results in the solar radiation test are irradiance. Reasonable control of the above key parameters can effectively ensure the acceleration spectrum of the test. The relevance and effectiveness of the actual South China Sea island and reef environmental tests.

Specifically, the temperature of the salt spray test is 45°C to 55°C. The temperature includes but not limited to: 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C. Further, the conditions of the salt spray test include: the temperature is 50° C., and the salt spray deposition rate is 1˜2 mL/h.80 cm ² .

In some specific examples, the salt spray solution used in the salt spray test is a neutral modified ASTM-D1141 artificial seawater simulated liquid, wherein the mass fraction of Cl ^- is 3%-4%. Further, the mass fraction of Cl ^- is 3.034%. This can improve the acceleration effect.

Specifically, taking 40L as an example, the composition of the neutral modified ASTM-D1141 artificial seawater simulation fluid is shown in Table 1 below:

Table 1 Chemicals content in 40L artificial seawater (unit g)

In some specific examples, the conditions of the solar radiation test include: the instantaneous extreme value of the irradiance is 1120W/m ² or the cumulative intensity conversion value of 5708.16W/m ² . Further, the instantaneous extreme value of irradiance used in the solar radiation test is 1120W/m ² . This makes the accelerated test more feasible and convenient for popularization and application.

In some specific examples, the conditions of the solar radiation test further include: a temperature of 45°C-50°C. The temperature includes but not limited to: 45°C, 46°C, 47°C, 48°C, 49°C, 50°C. Further, the temperature used in the solar radiation test is 49°C.

In some of these specific examples, the steps of applying coral salt include:

Mix coral salt powder and artificial seawater simulation liquid to prepare coral salt solution;

Coral salt solution is coated on the surface of the material to be tested.

In some specific examples, the artificial seawater simulant fluid is ASTM-D1141 artificial seawater simulant fluid.

In some specific examples, the coral salt powder has a mesh size of 800 mesh to 1200 mesh. Specifically, the mesh numbers of coral salt powder include but are not limited to: 800 mesh, 900 mesh, 1000 mesh, 1100 mesh, and 1200 mesh. Further, the mesh number of the coral salt powder is 1000 mesh.

In some specific examples, the mass fraction of the coral salt powder in the coral salt solution is 8%-12%. Specifically, the mass fraction of the coral salt powder in the coral salt solution includes, but is not limited to: 8%, 9%, 10%, 11%, and 12%. Further, the mass fraction of coral salt powder in the coral salt solution is 10%.

In some specific examples, in one cycle, the time for the salt spray test is 14-15 hours, and the time for the solar radiation test is 9 hours-10 hours. Further, in one cycle, the time for the salt spray test is 14.5 hours, and the time for the solar radiation test is 9.5 hours.

In some specific examples, the accelerated spectrum pattern of the material corrosion accelerated test method for simulating the South China Sea island and reef environment is shown in Figure 1: taking 24 hours as a cycle, the salt spray test time is 14.5 hours, and the solar radiation test time is 9.5 hours. h; Coral salt is coated before the salt spray test; the temperature of the salt spray test is 50°C, and the salt spray solution is a neutral modified ASTM-D1141 artificial seawater simulation liquid (Cl ^- mass fraction reaches 3.304%), and the salt spray settlement rate is : 1~2mL/h.80cm ² ; the instantaneous extreme value of irradiance used in the solar radiation test is 1120W/m ² , and the temperature is 49°C.

The following are specific examples.

Example 1

Sample: The base material is 2524 aluminum alloy, and the surface treatment method of the base material is chemical conductive oxidation treatment.

Test steps and conditions:

(1) Spray coral salt solution: take real coral salt and grind it into powder, use a 1000-mesh sieve to dry out the coral powder, mix it with ASTM-D1141 artificial seawater simulation liquid, and configure a coral salt solution with a mass fraction of 10%. Put it into a magnetic stirring device and rotate it evenly, and spray it on the sample until the surface is uniformly formed into a film.

(2) Salt spray test:

Temperature: 50°C, the salt spray solution is a neutral modified ASTM-D1141 artificial seawater simulation solution (use ASTM-D1141 artificial seawater as the bottom liquid, add NaCl for neutral modification, so that the Cl ^- mass fraction reaches 3.034%), salt The fog deposition rate is 1.0-2.0ml/h.80cm ² .

(3) Solar radiation test:

Temperature: 49°C, the solar radiation test adopts the instantaneous extreme value of 1120W/m ² . 24 hours is a cycle, the salt spray test time is 14.5 hours, and the solar radiation test time is 9.5 hours.

(4) The number of accelerated environmental test cycles is 30 times.

During the test, the weight, electrochemical impedance spectrum and polarization curve were tested. Among them, the weight loss analysis is to first use the derusting solution to derust it, and the configuration of the derusting solution is carried out in accordance with the relevant requirements in GB/T 16545-1996 "Clearing of Corrosion Products on Corrosion and Corrosion Specimens of Metals and Alloys". After derusting, rinse with distilled water and dry with cold wind, weigh with an analytical balance, and record the mass W ₁ after derusting. The electrochemical test uses the electrochemical workstation to test the electrochemical impedance spectrum and polarization curve of the sample after the test. In the electrochemical test, the traditional three-electrode system was adopted, the saturated calomel electrode was used as the reference electrode, the 20mm×20mm Pt electrode was used as the auxiliary electrode, the test sample was used as the working electrode, and its working area was 10mm×10mm. The disturbance voltage of the electrochemical impedance test is 20mV, and the scanning frequency range is 100KHz～0.01Hz. The scan rate of the potentiodynamic polarization test was 0.5mV·s ^-1 , and the voltage scan range (vs OCP) was -0.5V～1.5V. The test solution is 5% (mass fraction) NaCl solution.

In order to verify the effectiveness of the test, the weight and electrochemical test results during the accelerated environmental test were compared with those of the natural environment test on islands and reefs in the South China Sea. The results are shown in Table 2.

Table 2 Test results

Taking the weightlessness and low-frequency impedance modulus as characteristic parameters, the rank correlation coefficient method was used to evaluate the correlation between the accelerated environmental test and the natural environment test on islands and reefs in the South China Sea. strong correlation.

Taking the weightlessness and low-frequency impedance modulus as the characteristic parameters, the results of the 12-month natural environment test on South China Sea islands and reefs are basically the same as the 22-day accelerated environmental test. The acceleration factor AF is 13.78, and the acceleration is better.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, which are convenient for a specific and detailed understanding of the technical solution of the present invention, but should not be construed as limiting the protection scope of the invention patent. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. It should be understood that technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are within the protection scope of the appended claims of the present invention. Therefore, the scope of protection of the patent for the present invention shall be based on the content of the appended claims, and the description and drawings may be used to interpret the content of the claims.

Claims (11)

1. A material corrosion accelerated test method simulating the South China Sea island reef environment, is characterized in that, comprises the steps: Carry out a cyclic acceleration test on the material to be tested, and the test items in one cycle of the cyclic acceleration test are coral salt coating, salt spray test and solar radiation test in sequence; Among them, the conditions of the salt spray test include: the temperature is 45°C~55°C, the salt spray settlement rate: 1~2mL/h.80cm ² ; the salt spray solution used in the salt spray test is neutral modified ASTM-D1141 artificial seawater Simulated liquid, the mass fraction of Cl ⁱⁿ the salt spray solution is 3% ~ 4%; The conditions of the solar radiation test include: the temperature is 45°C~50°C, the irradiance adopts the instantaneous extreme value of 1110~ ^1130W /m2 or the cumulative intensity conversion value of 5700~ ^5710W /m2; The step of coating coral salt comprises: mixing coral salt powder and artificial seawater simulation liquid, preparing coral salt solution, coating said coral salt solution on the surface of said material to be tested, said coral salt in said coral salt solution The mass fraction of powder is 8%~12%; In one cycle, the time for salt spray test is 14h~15h, and the time for solar radiation test is 9h~10h. 2. The material corrosion accelerated test method for simulating the environment of islands and reefs in the South China Sea according to claim 1, characterized in that the conditions of the salt spray test include: the temperature is 50°C, and the salt spray settlement rate: 1~2mL/h.80cm ² . 3. The material corrosion accelerated test method for simulating the environment of islands and reefs in the South China Sea according to claim 1, wherein the material to be tested is a typical aviation material. 4. The material corrosion accelerated test method for simulating the South China Sea island and reef environment according to claim 1, characterized in that the conditions of the solar radiation test include: the instantaneous extreme value of the irradiance adopted is 1120W/ ^m2 or 5708.16W/m ² Cumulative intensity conversion values. 5. The material corrosion accelerated test method for simulating the South China Sea island and reef environment according to claim 1, characterized in that the instantaneous extreme value of irradiance used in the solar radiation test is 1120W/m ² . 6. The material corrosion accelerated test method for simulating the South China Sea island and reef environment according to claim 1, characterized in that the temperature used in the solar radiation test is 49°C. 7. The accelerated test method for material corrosion simulating the environment of islands and reefs in the South China Sea according to claim 1, characterized in that the mass fraction of Cl ⁱⁿ the salt spray solution is 3.034%. 8. The material corrosion accelerated test method for simulating the environment of islands and reefs in the South China Sea according to claim 1, wherein the coral salt powder has a mesh size of 800 mesh to 1200 mesh. 9. The material corrosion accelerated test method for simulating the South China Sea island and reef environment according to claim 8, wherein the coral salt powder has a mesh number of 1000 mesh. 10. The material corrosion accelerated test method for simulating the environment of islands and reefs in the South China Sea according to claim 9, wherein the mass fraction of the coral salt powder in the coral salt solution is 10%. 11. The material corrosion accelerated test method for simulating the South China Sea island and reef environment according to claim 10, characterized in that, in one cycle, the time for the salt spray test is 14.5 hours, and the time for the solar radiation test is 9.5 hours.

Images