Accelerated test method for evaluating failure behavior of metal anti-rust oil in protection process

Abstract

The invention provides an accelerated test method for evaluating a failure behavior in a protection process of metal anti-rust oil, which comprises the following steps: testing basic physical and chemical properties of anti-rust oil, determining a chemical aging acceleration coefficient, determining a physical aging acceleration coefficient, determining a physical-chemical aging coupling acceleration coefficient, and performing an accelerated test on the failure behavior in a storage process of an anti-rust oil-metal test piece. The method comprehensively considers the chemical oxidation and physical volatilization processes of the failure behavior of the metal anti-rust oil, is consistent with the aging process and failure mechanism of a real anti-rust oil application environment, and can accurately carry out an accelerated test for simulating the real aging process of the metal anti-rust oil; the method has the advantages of simple operation, high test accuracy, fast and efficient evaluation of the anti-aging capability of the anti-rust oil, and short test time and obvious evaluation effect of the accelerated test of the metal anti-rust oil by using the test method compared with a natural storage test.

Description

Technical Field

[0001] The invention relates to the technical field of material chemical industry and petroleum engineering, and in particular to an accelerated test method for evaluating failure behavior of metal anti-rust oil during storage protection. Background Art

[0002] Rust-preventive oil is a composition obtained by adding one or more rust-preventive additives (also known as oil-soluble corrosion inhibitors) and other auxiliary additives to a petroleum-based base oil. It is often used for temporary rust prevention during the inter-process, transportation, or storage of metal products (mainly steel products). It has the advantages of good effect, ease of use, low cost, easy construction, simple operation, and easy removal, and thus occupies an important position in the entire rust prevention work. It is an important means for protecting the surface of metal products and is currently produced and used in large quantities both at home and abroad. However, rust-preventive oil can undergo oxidation and deterioration and volatilization of the active ingredients during the long-term protection process of actual application, resulting in the loss of its rust-preventive ability. Therefore, the failure behavior of its storage protection process needs to be evaluated. The main methods currently used for evaluation include storage environment aging method and accelerated test method. However, the storage environment aging method usually requires several years or even longer time span, which is difficult to meet the rapid evaluation demand for the storage stability of rust-preventive oil. Therefore, it is urgent to develop an accelerated test method for evaluating the failure behavior of rust-preventive oil during storage.

[0003] Currently, commonly used accelerated testing methods typically examine aging indicators of rust preventive oils due to accelerated oxidation, such as appearance, flash point, viscosity, acid value, and compositional changes, at a defined accelerated test temperature. This allows the acceleration coefficient of the rust preventive oil's accelerated oxidation at high temperatures to be determined relative to that of the oil stored at room temperature. However, this method only focuses on chemical oxidation and deterioration during storage, while ignoring the physical aging process caused by the volatilization of active components during storage. In light of this, the present invention proposes an accelerated testing method that couples physical and chemical aging acceleration coefficients to evaluate the failure behavior of rust preventive oils during storage. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the present invention provides an accelerated test method for evaluating the failure behavior of rust preventive oil during storage, comprising: Basic physical and chemical properties test of rust-proof oil; Furthermore, the test is carried out in accordance with national or industry standard methods, including appearance, flash point, viscosity, acid value, pour point, and component composition tests.

[0005] Chemical aging acceleration factors were established; The temperature for the accelerated test is selected to be 25-100°C.

[0006] Furthermore, according to the fact that the self-oxidation rate of rust-proof oil follows the Arrhenius equation (Formula 1), oxidation experiments of rust-proof oil were carried out at different temperatures to obtain the corresponding relationship between oxidation rate and test temperature, thereby establishing the chemical aging acceleration coefficient.

[0007] (1) Where r is the reaction rate, A is the pre-exponential factor, ΔE is the reaction activation energy, T is the temperature, and R is a constant. Under unchanged storage conditions, the reaction activation energy ΔE and the pre-exponential factor A remain constant, and the oxidation rate is exponentially related to the test temperature. Therefore, increasing the temperature can accelerate the oxidation rate and accelerate storage.

[0008] Physical aging acceleration factors are established; The temperature for the accelerated test is selected to be 25-150°C.

[0009] Furthermore, the liquid evaporation rate is calculated according to Formula 2: (2) Where v represents the evaporation rate of the solvent, A is a constant, P represents the saturated vapor pressure of the solvent, RH represents the relative humidity, Ea is the activation energy, R is the gas constant, and T is the absolute temperature. Under normal conditions, the saturated vapor pressure, storage relative humidity, and activation energy of rust-proof oil are all constants, so the above formula can be simplified to Formula 3: (3) Based on the above formula, after testing the volatilization rate of the anti-rust oil at different temperatures, the anti-rust oil volatilization rate-temperature curve was fitted to establish the physical aging acceleration coefficient.

[0010] Furthermore, based on the chemical aging coefficient and the physical aging coefficient, the smaller acceleration coefficient is used as the physical-chemical aging coupling acceleration coefficient; Accelerated test of failure behavior of rust-proof oil-metal specimens during storage; Furthermore, the accelerated test of failure behavior of the rust-proof oil-metal test piece during storage includes: weighing the metal test piece, weighing the metal test piece after oiling, nitrogen purging, sealing the rust-proof oil-metal test piece, aging test of the rust-proof oil-metal test piece, and salt spray test; The weighing of the metal test piece includes: numbering, photographing, weighing and recording the mass of the metal test piece; The weighing of the metal test piece after oiling includes: immersing the metal test piece in anti-rust oil, hanging it to dry for 15 minutes, weighing the metal test piece again and recording the weight.

[0011] The nitrogen purge includes: placing the numbered metal test pieces on a customized test stand, then placing the test stand in the test box, fixing the test stand in the middle of the test box with high-temperature resistant tape, placing the N2 pipeline at the deepest part of the test box, covering the test box lid, turning on the N2, and purging for 15 minutes.

[0012] The anti-rust oil-metal test piece sealing includes: after the N2 purge is completed and the N2 pipeline is pulled out, the test box cover is immediately closed and sealed with a high-temperature resistant tape.

[0013] The rust-proof oil-metal test piece aging test includes: completing the preparation of all metal test pieces, opening the high and low temperature test chamber, reaching the test temperature and stabilizing for 2 hours, placing all test chambers in the high and low temperature test chamber in order, recording the time, and starting the test.

[0014] The salt spray test includes: after reaching the specified aging period, taking out the test box, videotaping the metal test piece, weighing it and recording the weight, placing the metal test piece in the salt spray test box for salt spray testing, and performing a neutral salt spray corrosion test in an artificial atmosphere. The test time is 1-9 days.

[0015] As can be seen from the above, the accelerated test method for the failure behavior of rust preventive oil during storage provided by this application includes testing of the basic physical and chemical properties of rust preventive oil, establishing a chemical aging acceleration factor, establishing a physical aging acceleration factor, establishing a physical-chemical aging coupling acceleration factor, and accelerating the failure behavior of rust preventive oil on metal specimens during storage. It comprehensively considers the chemical oxidation and physical volatilization processes of the failure behavior of rust preventive oil, and is consistent with the aging history and failure mechanism of the actual rust preventive oil application environment. It can accurately simulate the actual aging history of rust preventive oil and has high test accuracy. Compared with natural storage tests, the accelerated test of rust preventive oil using this test method accelerates the aging time by 1.53 times for every 10°C increase in the accelerated test temperature, resulting in high test accuracy and a short test time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the overall flow chart of the present invention. DETAILED DESCRIPTION

[0017] The following embodiments of the present invention are described in detail. The embodiments described below are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this field or the product specifications are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be obtained commercially.

[0018] In one aspect of the present invention, the present invention provides an accelerated test method for evaluating the failure behavior of rust preventive oil during storage, comprising the following steps: Basic physical and chemical properties test of rust-proof oil; Furthermore, referring to national or industry standard methods, the test process including appearance, flash point, viscosity, acid value, pour point, and component composition is as follows: (1) Flash point: The open cup flash point of rust-proof oil is tested according to GB / T 267 “Determination of flash point and fire point of petroleum products” (open cup method).

[0019] (2) Viscosity: Test the viscosity of anti-rust oil according to GB / T 265 "Determination of kinematic viscosity and calculation of dynamic viscosity of petroleum products".

[0020] (3) Acid value (neutralization value): The acid value of rust-proof oil is tested according to GB / T 7304 "Determination of neutralization value of petroleum products and lubricants" (potentiometric titration method).

[0021] (4) Pour point test: Refer to GB / T 3535-2006 Determination of pour point of petroleum products to test the pour point of rust-proof oil.

[0022] (5) Component composition: Infrared spectrometer is used to test the characteristic peaks of functional groups of each component of anti-rust oil.

[0023] Chemical aging acceleration factors were established; The temperature for the accelerated test is selected to be 25-100°C.

[0024] Furthermore, according to the fact that the self-oxidation rate of rust-proof oil follows the Arrhenius equation (Formula 1), oxidation experiments of rust-proof oil were carried out at different temperatures to obtain the corresponding relationship between oxidation rate and test temperature, thereby establishing the chemical aging acceleration coefficient.

[0025] (1) Where r is the reaction rate, A is the pre-exponential factor, ΔE is the reaction activation energy, T is the temperature, and R is a constant. Under unchanged storage conditions, the reaction activation energy ΔE and the pre-exponential factor A remain constant, and the oxidation rate is exponentially related to the test temperature. Therefore, increasing the temperature can accelerate the oxidation rate and accelerate storage.

[0026] Physical aging acceleration factors are established; The temperature for the accelerated test is selected to be 25-150°C.

[0027] Furthermore, the liquid evaporation rate is calculated according to Formula 2: (2) Where v represents the evaporation rate of the solvent, A is a constant, P represents the saturated vapor pressure of the solvent, RH represents the relative humidity, Ea is the activation energy, R is the gas constant, and T is the absolute temperature. Under normal conditions, the saturated vapor pressure, storage relative humidity, and activation energy of rust-proof oil are all constants, so the above formula can be simplified to Formula 3: (3) Based on the above formula, after testing the volatilization rate of the anti-rust oil at different temperatures, the anti-rust oil volatilization rate-temperature curve was fitted to establish the physical aging acceleration coefficient.

[0028] Furthermore, based on the chemical aging coefficient and the physical aging coefficient, the smaller acceleration coefficient is used as the physical-chemical aging coupling acceleration coefficient; Accelerated test on failure behavior of rust-proof oil-metal sheets during storage; Furthermore, the accelerated test of failure behavior of the rust-proof oil-metal test piece during storage includes: weighing the metal test piece, weighing the metal piece after oiling, nitrogen purging, sealing the rust-proof oil-metal piece, aging test of the rust-proof oil-metal piece, and salt spray test; The weighing of the metal test piece includes: numbering, photographing, weighing and recording the mass of the metal test piece; The weighing of the metal test piece after oiling includes: immersing the metal test piece in anti-rust oil, hanging it to dry for 15 minutes, weighing the metal test piece again and recording the weight.

[0029] The nitrogen purge includes: placing the numbered metal test pieces on a customized test stand, then placing the test stand in the test box, fixing the test stand in the middle of the test box with high-temperature resistant tape, placing the N2 pipeline at the deepest part of the test box, covering the test box lid, turning on the N2, and purging for 15 minutes.

[0030] The anti-rust oil-metal test piece sealing includes: after the N2 purge is completed and the N2 pipeline is pulled out, the test box cover is immediately closed and sealed with a high-temperature resistant tape.

[0031] The rust-proof oil-metal test piece aging test includes: completing the preparation of all metal test pieces, opening the high and low temperature test chamber, reaching the test temperature and stabilizing for 2 hours, placing all test chambers in the high and low temperature test chamber in order, recording the time, and starting the test.

[0032] The salt spray test includes: after reaching the specified aging period, taking out the test box, videotaping the metal test piece, weighing it and recording the weight, placing the metal test piece in the salt spray test box for salt spray testing, using the artificial atmosphere neutral salt spray corrosion test method, and the test time is 1-9 days.

[0033] In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples. Example

[0034] Example 1: Test materials: The anti-rust oil is F20-1 thin layer anti-rust oil, and the metal test piece is a martensitic steel sheet.

[0035] First, refer to national or industry standard methods for testing, including appearance, flash point, viscosity, acid value, pour point, and component composition. The test process is as follows: (1) Flash point: The open cup flash point of rust-proof oil is tested according to GB / T 267 “Determination of flash point and fire point of petroleum products” (open cup method).

[0036] (2) Viscosity: Test the viscosity of anti-rust oil according to GB / T 265 "Determination of kinematic viscosity and calculation of dynamic viscosity of petroleum products".

[0037] (3) Acid value (neutralization value): The acid value of rust-proof oil is tested according to GB / T 7304 "Determination of neutralization value of petroleum products and lubricants" (potentiometric titration method).

[0038] (4) Pour point test: Refer to GB / T 3535-2006 Determination of pour point of petroleum products to test the pour point of rust-proof oil.

[0039] (5) Component composition: Infrared spectrometer is used to test the characteristic peaks of functional groups of each component of anti-rust oil.

[0040] The accelerated test temperature was selected as 90°C. Based on the Arrhenius equation (Formula 1) for the auto-oxidation rate of rust-preventive oil, the corresponding relationship between the oxidation rate and the test temperature was obtained, thus establishing a chemical aging acceleration factor of 2, meaning that the chemical oxidation rate doubles for every 10°C increase in temperature.

[0041] The accelerated test temperatures were selected at 80°C, 100°C, 120°C, and 140°C. Based on the rust preventive oil volatilization rate formula (Formula 3), the corresponding relationship between volatilization rate and test temperature was obtained, thus establishing a physical aging acceleration factor of 1.53, meaning that the chemical oxidation rate increases by 0.53 times for every 10°C increase in temperature.

[0042] In the accelerated temperature simulation test, the temperature coefficient of accelerated oxidation deterioration is 2, and the temperature coefficient of accelerated volatilization is 1.53. Since the results of long-term storage of accelerated oxidation show that oxidation deterioration is not the main cause of the failure of the rust-proof oil, the temperature coefficient of accelerated volatilization of 1.53 is used as the physical-chemical coupling acceleration coefficient. Because the coefficient of accelerated volatilization is smaller than the coefficient of accelerated oxidation, the oxidation of the rust-proof oil is still carried out at the same time during accelerated volatilization, and the actual oxidation time is longer than the test equivalent time, so oxidation will not affect the simulation test results of the rust-proof oil volatilization failure.

[0043] After comprehensive analysis of the test data after accelerated aging and accelerated volatilization, the accelerated temperature and acceleration factor were determined to be 155°C and 1.53. Metal specimens were prepared with dimensions of 250×180×2mm (length×width×thickness). The specimens were polished with 2000# sandpaper to remove any surface coating or passivation, wiped clean with petroleum ether, allowed to air dry, and weighed. Anti-rust oil was evenly sprayed onto the metal specimens using a spray gun. The metal specimens were then suspended and allowed to stand for 24 hours until the oil stopped dripping. The oil-sprayed metal specimens were weighed and placed horizontally on a metal rack. The rack was then placed in a metal packaging box. The opening of the box was wrapped with a breathable multi-layer non-woven fabric to prevent the air from the environmental test chamber from directly hitting the metal specimens. The box was then placed in the environmental test chamber and accelerated aging tests were conducted for 69.6 hours, corresponding to a two-year storage period. After the simulated two-year storage period, all metal specimens were removed and subjected to a nine-day salt spray test to determine the rust weight gain of the metal specimens.

[0044] Example 2: The test method was essentially the same as in Example 1, except that the accelerated aging test was initiated in an environmental chamber for 174 hours, corresponding to a 5-year storage period. After the simulated 5-year storage period, all metal specimens were removed and subjected to a 9-day salt spray test to determine the rust and weight gain of the metal specimens.

[0045] Example 3: The test method was essentially the same as in Example 1, except that the accelerated aging test was initiated in an environmental chamber for 417.6 hours, corresponding to a 12-year storage period. After the simulated 12-year storage period, all metal specimens were removed and subjected to a 9-day salt spray test to determine their rust weight gain.

[0046] Example 4: The test method was essentially the same as in Example 1, except that the accelerated aging test was initiated in an environmental chamber for 626.4 hours, corresponding to an 18-year storage period. After the simulated 18-year storage period, all metal specimens were removed and subjected to a 9-day salt spray test to determine their rust weight gain.

[0047] Comparative Example 1: Metal specimens coated with anti-rust oil that had been naturally aged for two years were used as control samples. After the two-year storage period, all metal specimens were taken out and subjected to a nine-day salt spray test to obtain the rust weight gain of the metal specimens.

[0048] The storage aging test results of Examples 1-4 and Comparative Example 1 are shown in Table 1.

[0049] Table 1 Any matters not mentioned above shall be subject to the existing technology.

[0050] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0051] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art of the present invention may make various modifications or additions to the described specific embodiments or replace them in similar ways, but they will not deviate from the direction of the present invention or exceed the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the scope of protection of the present invention.

Claims

1. An accelerated test method for evaluating the failure behavior of rust-preventive oil during storage, characterized in that: include: Obtain basic physical and chemical performance data of rust-proof oil, establish chemical aging acceleration coefficient and physical aging acceleration coefficient; Obtaining a physical-chemical aging coupling acceleration coefficient based on the chemical aging acceleration coefficient and the physical aging acceleration coefficient; An accelerated test of failure behavior of the rust-proof oil-metal sheet during storage is performed based on the physical-chemical aging coupling acceleration coefficient; wherein the accelerated test includes weighing the metal sheet, weighing the metal sheet after oiling, nitrogen purging, sealing the rust-proof oil-metal sheet, aging test of the rust-proof oil-metal sheet, and salt spray test.

2. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The chemical aging acceleration factor is established and calculated according to the following formula: Where r is the reaction rate, A is the pre-exponential factor, △E is the reaction activation energy, T is the temperature, and R is a constant. When the storage conditions remain unchanged, the reaction activation energy △E and the pre-exponential factor A remain constant, and the oxidation rate is exponentially related to the test temperature. Therefore, increasing the temperature can speed up the oxidation rate and accelerate the storage effect.

3. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The chemical aging acceleration factor is established and calculated according to the following formula: In the formula, v represents the volatilization rate of the solvent, A is a constant, P represents the saturated vapor pressure of the solvent, RH represents the relative humidity, Ea is the activation energy, R is the gas constant, and T is the absolute temperature. Under normal conditions, the saturated vapor pressure, storage relative humidity, and activation energy of the rust-proof oil are all constants, so the above formula can be simplified to the following formula: 。 4. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The physical-chemical aging coupling acceleration coefficient is established by selecting the smaller acceleration coefficient of the chemical aging coefficient and the physical aging coefficient.

5. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The weighing of the metal piece after oiling includes: immersing the metal test piece in anti-rust oil, hanging it to dry for 15 minutes, weighing the metal test piece again and recording the weight.

6. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The weighing of the metal piece after oiling includes: immersing the metal test piece in anti-rust oil, hanging it to dry for 15 minutes, weighing the metal test piece again and recording the weight.

7. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The nitrogen purge includes: placing the numbered metal test pieces on a customized test stand, then placing the test stand in the test box, fixing the test stand in the middle of the test box with high-temperature resistant tape, placing the N2 pipeline at the deepest part of the test box, covering the test box lid, turning on the N2, and purging for 15 minutes.

8. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The anti-rust oil-metal sheet sealing includes: after the N2 purge is completed and the N2 pipeline is pulled out, the test box cover is immediately closed and sealed with a high-temperature resistant tape.

9. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The anti-rust oil-metal sheet aging test includes: completing the preparation of all metal test pieces, opening the high and low temperature test chamber, reaching the test temperature and stabilizing for 2 hours, placing all test chambers in the high and low temperature test chamber in order, recording the time, and starting the test.

10. The accelerated test method for failure behavior of rust preventive oil during storage according to claim 1, characterized in that: The salt spray test includes: after reaching the specified aging period, taking out the test box, videotaping the metal test piece, weighing it and recording the weight, placing the metal test piece in the salt spray test box for salt spray testing, and performing a neutral salt spray corrosion test in an artificial atmosphere. The test time is 1-9 days.

Images