JP3668743B2 - Salt particle generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of this application relates to a salt particle generator. More specifically, the invention of this application relates to a salt particle generator useful for a corrosion acceleration test for evaluating the corrosion of a metal material.
[0002]
[Prior art and its problems]
2. Description of the Related Art Conventionally, a salt spray test apparatus defined in JIS-Z2371 has been used as a corrosion acceleration test apparatus necessary for estimating and evaluating the corrosion amount of metal materials.
Also in the CASS test method defined in ISO-9227, a salt spray test is defined as an accelerated test for metal corrosion.
[0003]
Furthermore, as a salt spray test apparatus used for a corrosion promotion test method using sea salt, an automatic salt spray test apparatus for surface-treated steel sheets is disclosed in Japanese Patent Application Laid-Open No. 09-178646.
However, in these conventional methods, salt water, which is the cause of corrosion, is atomized and sprayed on the test piece, or salt water is directly showered and sprayed on the test piece, so the test piece is always wet. This was far from the corrosion conditions of the materials that were actually placed in the natural environment.
[0004]
On the other hand, the inventors of this application installed a gold test piece which does not cause corrosion in an actual beach and a salt spray test apparatus, and attempted to observe salt particles adhering to the test piece under a microscope. The specimen was fixed on the actual coast, and the sea salt particles flying from the sea and adhering to the specimen were observed with a scanning electron microscope.
FIG. 1 of the accompanying drawings shows a scanning electron micrograph of sea salt particles collected on the coast.
[0005]
As shown in FIG. 1, sea salt particles collected in an actual environment have a small size of about 30 μm, and salt crystals are deposited at the center. On the other hand, the salt particles collected in the conventional accelerated test apparatus were soaked in the whole that a large salt lump that could not be observed with a scanning electron microscope or the like was formed.
That is, in the conventional corrosion acceleration test equipment, salt particles that are completely different from the actual environment are attached, so the corrosion situation is essentially different. Therefore, the result of evaluation with the corrosion acceleration test equipment is the actual environment. There was a problem that it did not agree with the result.
[0006]
Then, this invention makes it a subject to provide the corrosion acceleration | stimulation test apparatus which can reproduce the adhesion condition of the sea salt particle | grains in a natural environment.
[0007]
[Means for Solving the Problems]
The invention of this application, as to solve the problem as described above, includes an apparatus for use in accelerated corrosion tests, salt water supply device, water flow generator, the buffer space, the test piece holding tank, and a blower, a buffer space is arranged between the running water generator specimen holding tank, the wind speed blower occurs as V (m · sec ^-1), the length of the buffer space and L (m), the relationship between them The salt particle generator is characterized in that the value of V / L is in the range of 0.2 (sec ⁻¹ ) or more and 2.5 (sec ⁻¹ ) or less .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The invention of this application has the features as described above. Next, embodiments of the invention will be described.
FIG. 2 of the accompanying drawings illustrates the configuration of the salt particle generator of the present invention.
[0010]
As shown in FIG. 2, the apparatus, salt water supply device (1), running water generator (2), the buffer space (3), the test piece holding tank (4), and is composed of the blower (5) It is.
[0011]
The salt water replenisher (1) is not particularly limited in terms of its mechanism and structure, but has a mechanism for continuously replenishing a constant amount of salt water to the flowing water generator (2) and reusing the drainage. desirable.
Further, the flowing water generator (2) is not particularly limited in terms of its structure, and generates a constant flow of waterfall-like flowing water, or generates a constant flow of fountain-like flowing water and drops it. Is. Furthermore, it is desirable to be able to sufficiently generate fine particles of salt water having a size of 50 μm or less by combination with the blower (5). Although there is no problem with the flow rate as much as possible, practically it is preferably between 0.1 l / min and 10 l / min.
[0012]
The buffer space (3) is a space that is sorted by the particle diameter while the salt particles are transported from the flowing water generator (2) to the test piece holding tank (4).
The specimen holding tank (4) is not particularly limited in terms of its mechanism and structure, but when holding a plurality of specimens, it is necessary to consider that the amount of salt particles adhering to each specimen does not change. For this reason, a mechanism for rotating the test piece or changing the position is appropriately selected.
[0013]
The blower (5) is used to blow the flowing water generated by the flowing water generator (2) and generate fine particles of water, and is not particularly limited in structure, but at least 1 What generates a wind speed of (m / sec) or higher is desirable.
Furthermore, in this invention, the relationship between the wind speed generated by the blower (5) and the length of the buffer space (3) between the flowing water generator (2) and the test piece holding tank (4) can be set and changed. To be considered.
[0014]
The salt particles generated by the flowing water generator (2) fly inside the buffer space (3), are selected according to the particle diameter, and reach the test piece holding tank (4). The length of the buffer space (3) is L (m), the wind speed is V (m · sec ⁻¹ ), and the relationship between the two is that the value of V / L is 0.2 (sec ⁻¹ ) or more. Sea salt closer to the actual environment can be obtained within a range of 5 (sec ^-1 ) or less. If it is less than this range, the size of the salt particles is large. For example, as shown in the photograph of A of Example 1, particles exceeding 50 μm are mixed, resulting in a state different from the actual atmospheric environment. On the other hand, if it is above this range, the salt particles will be too small and the amount of flying will be small, making it impractical.
[0015]
The present invention provides a salt particle generator that enables the realization of a new corrosion acceleration test that has never been achieved with the above-described configuration. The configuration and features of the operation and effect thereof will be described in more detail below. A description will be given along an example. Of course, the present invention is not limited to the following examples.
[0016]
【Example】
Example 1
Using the apparatus illustrated in FIG. 2 of the accompanying drawings, the value of V / L is set to 0.1, 1.0, 3.0, artificial seawater is used as a solution, and Au that does not corrode at room temperature is used. Salt particles were adhered to the test piece.
[0017]
In FIG. 3 of the attached drawings, A is set to V / L = 3.0, B is set to V / L = 1.0, and C is set to V / L = 0.1. FIG. 2 illustrates a microphotograph of adhered salt particles. FIG.
FIG. 3B shows the result in the desired V / L range as described above. On the other hand, FIG. 3A shows the case where V / L is not less than the above range, and FIG.
[0018]
In FIG. 3B of the attached drawings, the particle diameter is almost the same as the salt particles deposited on the test piece on the actual coast shown in FIG. 1, and the appearance is very similar. On the other hand, in FIG. 3A, the size of the attached salt particles is large and the density is too high. In FIG. 3C, the size of the salt particles is small and the amount thereof is also small.
[0019]
In other words, by using the apparatus according to the present invention, it is possible to arbitrarily deposit a very large salt particle, a salt particle having a shape very close to the actual state of adhesion on the coast, and a fine salt particle on the test piece. It was confirmed that there was.
Example 2
A stainless steel plate equivalent to SUS304 was installed in the same apparatus of the present invention as in Example 1 using a NaCl aqueous solution as the solution, and salt particles were adhered under the condition of V / L = 1.0, and the amount of salt particles changing with time. Was measured. For the measurement of the amount of salt particles, the test piece was washed with distilled water and the Cl component contained therein was chemically analyzed to determine the amount of adhesion.
[0020]
FIG. 4 of the accompanying drawings is a graph showing the relationship between time and the amount of adhering salt particles.
As is clear from FIG. 4, the amount of salt attached is proportional to time, and it was confirmed that the amount of salt attached to the surface of the test piece can be controlled by time using the apparatus of the present invention.
[0021]
【The invention's effect】
As described above in detail, by using the salt particle generating apparatus provided by the invention of this application, it is possible to deposit on the specimen to a known amount of salt particles of interest in the same state as the natural environment, Accelerated test with high accuracy of outdoor corrosion can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an electron micrograph of sea salt particles collected on a coast.
FIG. 2 is a schematic configuration diagram illustrating the configuration of the salt particle generating device of the present invention.
FIG. 3 is a view illustrating a micrograph of salt particles attached to an Au test piece by the apparatus of the present invention. A is the result when V / L = 3.0, B is V / L = 1.0, and C is V / L = 0.1.
FIG. 4 is a diagram illustrating the relationship between time and the amount of adhering salt particles using a stainless steel plate as a test piece.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Salt water replenisher 2 Flowing water generator 3 Buffer space 4 Test piece holding tank 5 Blower

Claims (1)

An apparatus for use in accelerated corrosion tests, salt water supply device, water flow generator, the buffer space, the test piece holding tank, and equipped with a blower, the buffer space is arranged between the running water generator specimen holding tank The velocity of the air generated by the blower is V (m · sec ⁻¹ ), the length of the buffer space is L (m), and the relationship between the two is that the value of V / L is 0.2 (sec ⁻¹ ) or more. A salt particle generator characterized by being in a range of 2.5 (sec ^-1 ) or less .

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