Test method for simulating corrosion course of low alloy steel under marine industrial atmospheric environment

A low-alloy steel and atmospheric environment technology, used in weather resistance/light resistance/corrosion resistance, measuring devices, instruments, etc.

Inactive Publication Date: 2013-05-15
中广核工程有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there are not many reports on the corrosion of low-alloy steels in the marine industrial atmospheric environment, and there are few reports on the corrosion research of simulated low-alloy steels in the marine industrial atmospheric environment

Method used

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  • Test method for simulating corrosion course of low alloy steel under marine industrial atmospheric environment
  • Test method for simulating corrosion course of low alloy steel under marine industrial atmospheric environment
  • Test method for simulating corrosion course of low alloy steel under marine industrial atmospheric environment

Examples

Experimental program
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Effect test

Embodiment 1

[0041] The test material is the above-mentioned low-alloy steel P265GH, and a certain concentration ratio of NaCl and NaHSO is prepared in advance. 3 solution, the solvent is distilled water and absolute ethanol mixed at a volume ratio of 1:1. In the present embodiment, calculate the concentration of the prepared solution according to the following formula:

[0042] C NaHSO3 =S×R SO3 × M NaHSO3 ×k / (V×M SO3 ) (1)

[0043] C NaCl =S×R Cl × M NaCl ×k / (V×M Cl ) (2)

[0044] in:

[0045] The surface area of ​​a single surface of the sample S = 2.4cm × 2.0cm = 4.80cm 2 ;

[0046] Amplification factor k=10, unit is d (day);

[0047] The volume V of the salt solution taken by the micro-sampler = 10×10 -3 mL;

[0048] The sulfation rate R of the actual atmosphere in the simulated area SO3=1.154mg / 100cm 2 d(day);

[0049] The sedimentation rate R of sea salt particles in the simulated area Cl =0.079mg / 100cm 2 d(day);

[0050] m NaHSO3 , M SO3 , M NaCl...

Embodiment 2

[0054] The test material is the above-mentioned low-alloy steel P265GH, and a certain concentration ratio of NaCl and NaHSO is prepared in advance. 3 solution, the solvent is distilled water and absolute ethanol mixed at a volume ratio of 1:1. In this example, NaHSO 3 The concentrations of NaCl and NaCl are the same as in Example 1, being 72mg / mL and 6.24mg / mL respectively.

[0055] Use a micropipette to take 10 μL of the solution and apply it evenly on both surfaces of the sample, and then dry it slowly with a hair dryer. Cycle once every 24 hours according to the sequence of "wet→dry", in which: the test temperature is 30°C, the wet and dry process are both 12h, the relative humidity of the wet and dry process is 80% and 10% respectively, and the test time is 1, 7 , 14, 28, 42 days. From image 3 It can be seen from the curve of simulated corrosion weight loss versus time in the simulation test that the corrosion weight loss of the simulation test is in line with the pow...

Embodiment 3

[0056] Embodiment 3 (comparative example)

[0057] According to the ISO-4542 standard, the atmospheric exposure test of low alloy steel P265GH was carried out in a coastal area of ​​Liaoning, and the time was 3, 6 and 12 months respectively. From Figure 5 It can be seen that the corrosion weight loss of the samples increases with the increase of exposure time. The X-ray diffraction spectrum of corrosion products shows that the rust layer is mainly composed of β-FeOOH, α-FeOOH and γ-FeOOH ( Figure 4 ). Table 2 shows the comparison of element distribution in the cross-section of the outdoor exposure test for 6 months and the indoor simulation test for 14 days. The rust layer cross-sections all contain foreign elements such as Cl and S.

[0058] Table 2. Comparison of cross-sectional element distribution between outdoor exposure test and indoor simulation test

[0059]

[0060] It can be seen from the examples and comparative examples that the corrosion weight loss of th...

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Abstract

The invention relates to simulation technology of atmospheric corrosion of low alloy steel, and particularly provides a test method for simulating corrosion course of low alloy steel under marine industrial atmospheric environment. According to the invention, low alloy steel is used as a test material, and NaHSO3 and NaCl of different concentration ratios are deposited on the surface of a sample to be tested in advance, and alternate dry and wet tests are carried out according to the order of a wet test first and a dry test next, wherein test temperature is 30 DEG C, a wet test and a dry testboth last for 12 hours, relative humidity of the wet test and the dry test are 80% and 10% respectively, and the whole test lasts for 1 to 42 days. The test method provided in the invention has the characteristics of simulation, acceleration capability and reproducibility, and can be used to simulate marine industrial atmospheric corrosion course, to study corrosion behavior of various low alloy steel under an environment similar to the atmospheric environment and to evaluate and predict corrosion resistance of low alloy steel to marine industrial atmosphere, providing the basis for reasonable selection of low alloy steel and selection of appropriate protection methods.

Description

technical field [0001] The invention relates to atmospheric corrosion simulation technology of low-alloy steel, and in particular provides a test method for simulating the corrosion process of low-alloy steel in marine industrial atmospheric environment. Background technique [0002] Low-alloy steel is a structural material widely used in the nuclear power industry. At present, most of the nuclear power projects built and under construction in my country are distributed in coastal areas, such as Daya Bay Nuclear Power Plant and Hongyanhe Nuclear Power Plant. Most nuclear power plants are located in the marine atmospheric environment. When industrial enterprises are involved, it will lead to changes in trace elements in the local atmosphere of the region. In addition to a large number of sea salt particles, the atmosphere also contains a certain amount of industrial pollutants (such as SO 2 Wait). Study shows: sea salt particle deposition and SO 2 Pollution is the main envir...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N17/00
Inventor 魏伟汪川于全成谢陈平王振尧
Owner 中广核工程有限公司
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