A method for monitoring the corrosion capacity of a cyclic salt spray test chamber

Abstract

The method discloses a kind of monitoring cyclic salt fog test box corrosion ability method, S1: preparation material and reagent;S2: material is placed in acetone ultrasonic cleaning 6 minutes after drying and weighing;S3: after cleaning 3 series / 7 series composite layer round pipe is placed in 60 degrees deionized water heating 1 minute, and it is sealed;S4: these 3 series / 7 series composite layer round pipe is placed in three different positions in corrosion chamber horizontally, with sample and carries out SWAAT test;S5: clean 3 series / 7 series composite layer round pipe is placed in concentrated nitric acid with concentration of 67%, using ultrasonic cleaning technology to it washes 6 minutes;S6: with deionized water washes residual nitric acid and carries out weighing;S7: calculate the average area of weight loss.The method disclosed in the method for monitoring the corrosion ability of cyclic salt fog test box, the performance of the test sample is stable during the experiment, sensitive to the corrosion environment, can timely response the change of corrosion chamber environment, easy to operate in the process of test, overall cost is lower.

Description

TECHNICAL FIELD

[0001] The present method relates to the field of aluminum alloy, in particular to a method for monitoring the corrosion capacity of a cyclic salt spray test chamber. BACKGROUND

[0002] With the continuous development and maturity of the aluminum industry, the reliability of aluminum alloy materials in terms of corrosion resistance becomes particularly important, especially for aluminum heat exchangers. Corrosion testing and subsequent evaluation of the results are a very important test method for their development. Today, there are many corrosion laboratories that can test the corrosion performance of various types of aluminum alloy products and evaluate the corrosion results. However, the corrosion capacity of the corrosion chamber often changes abnormally due to changes in parameters, accessories, and the surrounding environment, which affects the results and may result in different results from different laboratories, or even different results from different test chambers in the same laboratory. This has a great impact on the evaluation and research of the corrosion performance of the product.

[0003] ASTM G-85 A3 and PV1208 are one of the main test reference standards for aluminum heat exchangers. In this standard, at least 16 hours of continuous spraying solution is collected, and the settlement rate is calculated to check the corrosion capacity of the corrosion test chamber. However, this test method has the following disadvantages: 1. Since the settlement rate test is different from the test method during the formal test, it can only be performed before and after the formal test, and it cannot monitor the corrosion capacity of the corrosion chamber during the formal test; 2. When testing, changes in temperature, humidity, or other parameters that may cause changes in the test chamber environment cannot be monitored. In addition, there are many parameter specifications in this standard, all of which are within a certain range, such as the settlement rate value range requirement of 1 ml / (h·80cm 2 )-2 ml / (h·80cm 2 ), and the placement position of the settlement rate collector. The adjustable range is very large during corrosion testing, resulting in different test results. Therefore, if appropriate corrosion capacity monitoring measures are not taken during the experiment, abnormal corrosion capacity may occur during the experiment, which will not be discovered, further leading to abnormal corrosion results, and thus causing misjudgment of the corrosion performance of aluminum alloy products, and also causing large differences in test results of the same product between different corrosion test chambers and different laboratories, but no reason for the difference can be found.

[0004] Therefore, it is necessary to propose a method for monitoring the corrosion capacity of a cyclic salt spray test chamber to solve the above problems.

[0005] Method content

[0006] The main purpose of the present method is to provide a method for monitoring the corrosion capacity of a cyclic salt spray test chamber, which can effectively solve the problems in the background art.

[0007] To achieve the above object, the technical scheme adopted by the method is:

[0008] A method for monitoring the corrosion capacity of a cyclic salt spray test chamber, comprising the following operation steps:

[0009] S1: Prepare materials and reagents, materials include 3 / 7 composite layer circular pipe, weighing device, drying machine, heating vessel, rubber plug, corrosion chamber, soft brush, reagents include acetone, deionized water, concentrated nitric acid and alcohol;

[0010] S2: Place the 3 / 7 composite layer circular pipe in acetone and ultrasonically clean for 6 minutes, dry at a temperature of 37°C, and then weigh and record the weight after drying;

[0011] S3: Place the cleaned 3 / 7 composite layer circular pipe in deionized water at 60°C for 1 minute, then quickly seal the two ends of the pipe with a rubber plug that matches the size of the 3 / 7 composite layer circular pipe, and the heat of the 3 / 7 composite layer circular pipe can ensure good sealing effect of the rubber plug;

[0012] S4: Place the 3 / 7 composite layer circular pipes horizontally at three different positions in the corrosion chamber, and test the samples, which need to be tested for 7 days, then remove the pipes and remove the rubber plug;

[0013] S5: Rinse the surface of the 3 / 7 composite layer circular pipe with deionized water, gently brush the accumulated salt on the surface with a soft brush, then clean the 3 / 7 composite layer circular pipe with concentrated nitric acid with a concentration of 67% using ultrasonic cleaning technology for 6 minutes;

[0014] S6: Clean the residual nitric acid with deionized water, rinse the 3 / 7 composite layer circular pipe with alcohol, and weigh the 3 / 7 composite layer circular pipe after drying at a temperature of 37°C;

[0015] S7: Calculate the average area weight loss in mg / cm 2 .

[0016] Preferably, during the test, the test is sensitive to the corrosion environment of the corrosion test chamber, when the corrosion chamber settlement rate, temperature, humidity or other parameters change, the weight loss of the selected 3 / 7 composite layer circular pipe will change, at this time the abnormal reason can be found out to ensure the accuracy of the results.

[0017] Preferably, the weight of the 3 / 7 composite layer circular pipe before and after corrosion needs to be weighed, and the change of the corrosion capacity at different positions in the test chamber can be reflected by the placement position and number during the monitoring process.

[0018] Beneficial effects

[0019] Compared with existing technologies, this method provides a way to monitor the corrosion resistance of a cyclic salt spray test chamber, which has the following advantages:

[0020] 1. This method for monitoring the corrosion capacity of a cyclic salt spray test chamber uses a 3-series / 7-series composite layered round tube as the reference sample for monitoring corrosion capacity. The outer layer is a 7-series alloy. The 7-series composite layer exhibits transverse corrosion in cyclic corrosion tests, and its weight loss increases linearly with the number of corrosion days. This method can effectively reflect the changing trend of the corrosion capacity of the corrosion chamber over time. Even in short-cycle tests, this type of reference tube can show significant weight loss. During the test, the test is sensitive to the corrosion environment of the corrosion test chamber. When the sedimentation rate, temperature, humidity, or other parameters of the corrosion chamber change, the weight loss of the reference tube will also change, facilitating timely identification of abnormal causes and ensuring the accuracy of the results. The method is easy to operate, requiring only weighing before and after corrosion. The changes in corrosion capacity at different locations within the test chamber can be reflected by the placement and quantity of the reference tubes. Simultaneously, the corrosion capacity of the corrosion test chamber is monitored during the cyclic corrosion test, ensuring the accuracy of the results. Furthermore, the aluminum alloy reference sample will not contaminate the test chamber used for aluminum alloy corrosion tests. The reference sample exhibits stable performance during the experiment, is sensitive to the corrosion environment, and can promptly reflect changes in the corrosion chamber environment. The operation is simple and the overall cost is low. Attached Figure Description

[0021] Figure 1 This is a graph of the weightlessness data of the reference tube involved in this method. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this method easier to understand, the following describes the method in more detail with reference to specific implementation methods.

[0023] like Figure 1 As shown, a method for monitoring the corrosion resistance of a cyclic salt spray test chamber includes the following steps:

[0024] S1: Prepare materials and reagents. Materials include 3-series / 7-series composite layered round tubes, weighing apparatus, dryer, heating dish, rubber stopper, corrosion chamber, and soft brush. Reagents include acetone, deionized water, concentrated nitric acid, and alcohol.

[0025] S2: Place the 3-series / 7-series composite layered round tube in acetone for ultrasonic cleaning for 6 minutes, dry it at a temperature of 37℃, weigh it after drying and record the weight.

[0026] S3: After cleaning, the 3 / 7 composite layer round pipe is heated in deionized water at 60°C for 1 minute, then a rubber plug is used to quickly seal the two ends of the pipe, and the heat of the 3 / 7 composite layer round pipe can ensure good sealing effect of the rubber plug.

[0027] S4: Place the 3 / 7 composite layer round pipes horizontally in three different positions in the corrosion chamber, and conduct salt spray test on the samples. The test needs to last for 7 days, and after seven days, the pipes are taken out and the rubber plugs are removed.

[0028] S5: Rinse the surface of the 3 / 7 composite layer round pipe with deionized water, and gently brush the accumulated salt on the surface with a soft brush. Then place the 3 / 7 composite layer round pipe in concentrated nitric acid with a concentration of 67%, and use ultrasonic cleaning technology to clean it for 6 minutes.

[0029] S6: Clean the residual nitric acid with deionized water, rinse the 3 / 7 composite layer round pipe with alcohol, and then weigh the 3 / 7 composite layer round pipe after drying at a temperature of 37°C.

[0030] S7: Calculate the average area weight loss in mg / cm 2 ， During the test, the test is sensitive to the corrosion environment of the corrosion test chamber. When the corrosion chamber's settlement rate, temperature, humidity, or other parameters change, the weight loss of the selected 3 / 7 composite layer round pipe will also change. At this time, the cause of the abnormality can be found to ensure the accuracy of the results. The weight of the 3 / 7 composite layer round pipe before and after corrosion needs to be weighed, and the change in corrosion capacity at different positions in the test chamber can be reflected by the placement position and number during the monitoring process.

[0031] It should be noted that the method is a method for monitoring the corrosion ability of a cyclic salt spray test chamber, and a 3 / 7 composite layer circular tube is selected as a reference sample for monitoring the corrosion ability, the outer layer is a 7 alloy, the 7 composite layer shows transverse corrosion in the salt spray test, and the weight loss will increase linearly with the corrosion days, which can well reflect the change trend of the corrosion ability of the corrosion chamber with time, even if the test period is short, such reference tube can also show obvious weight loss, in the test process, the test is sensitive to the corrosion environment of the corrosion test chamber, when the corrosion chamber settlement rate, temperature, humidity or other parameters change, the weight loss of the reference tube will change, which is convenient for finding abnormal reasons in time, ensuring the accuracy of the results, the operation is convenient, only the weight before and after corrosion needs to be weighed, the change of the corrosion ability of the test chamber at different positions can be reflected by the placement position and quantity, and the corrosion ability of the corrosion test chamber in the salt spray test process is monitored, the accuracy of the results is ensured, and the reference sample made of aluminum alloy does not pollute the test chamber for corrosion test of aluminum alloy, the performance of the reference sample is stable in the experiment process, sensitive to the corrosion environment, can timely reflect the change of the corrosion chamber environment, the operation is simple during the test process, and the overall cost is low.

[0032] The above shows and describes the basic principles and main features of the method and the advantages of the method. Those skilled in the art should understand that the method is not limited by the above examples, the above examples and descriptions in the specification are only to illustrate the principles of the method, and various changes and improvements can be made to the method without departing from the spirit and scope of the method, and these changes and improvements all fall within the scope of the claimed method. The scope of protection of the method is defined by the appended claims and their equivalents.

Claims

1. A method of monitoring the corrosion capacity of a cyclic salt spray test chamber, characterised by: The method comprises the following steps: S1: preparing materials and reagents, the materials include 3 / 7 composite layer round pipe, weighing device, drying machine, heating vessel, rubber plug, corrosion chamber, soft brush, and the reagents include acetone, deionized water, concentrated nitric acid and alcohol, the outer layer is 7 alloy, the 7 composite layer shows transverse corrosion in the salt spray test, and the weight loss will increase linearly with the corrosion days; S2: placing the 3 / 7 composite layer round pipe in acetone for ultrasonic cleaning for 6 minutes, drying at a temperature of 37 DEG C, and then weighing and recording the 3 / 7 composite layer round pipe after drying; S3: placing the cleaned 3 / 7 composite layer round pipe in deionized water at 60 DEG C for heating for 1 minute, then quickly sealing the two ends of the pipe with a rubber plug matched with the size of the 3 / 7 composite layer round pipe, and the heat of the 3 / 7 composite layer round pipe can ensure good sealing effect between the rubber plug and the pipe; S4: placing the 3 / 7 composite layer round pipes horizontally at three different positions in the corrosion chamber, and carrying out corrosion test on the samples, and the test needs to last for 7 days, then the pipes are taken out, and the rubber plug is removed; S5: rinsing the surface of the 3 / 7 composite layer round pipe with deionized water, gently brushing the adhered salt on the surface with a soft brush, then cleaning the 3 / 7 composite layer round pipe in concentrated nitric acid with a concentration of 67% for 6 minutes by using ultrasonic cleaning technology; S6: cleaning residual nitric acid with deionized water, rinsing the 3 / 7 composite layer round pipe with alcohol, and weighing the 3 / 7 composite layer round pipe after drying at a temperature of 37 DEG C; S7: calculating the average area weight loss, in mg / cm2.

2. The method for monitoring the corrosion capability of a cyclic salt spray test chamber according to claim 1, characterized in that: During the test, when the corrosion box settlement rate, temperature, humidity or other parameters change, the weight loss of the selected 3 / 7 composite layer round pipe will also change, at this time, the abnormal reason can be found to ensure the accuracy of the results.

3. The method for monitoring the corrosion capability of a cyclic salt spray test chamber according to claim 1, characterized in that: The weight of the 3 / 7 composite layer round pipe before and after corrosion needs to be weighed, and the change of corrosion capacity at different positions in the test chamber is reflected by the placement position and quantity during the monitoring process.

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