JP2023158870A - Construction capable of preventing adhesion of marine organisms thereto - Google Patents

Abstract

To provide a construction capable of preventing adhesion of marine organisms thereto so that adhesion of organisms such as shellfish and algae in the sea can be less than the prior art or even prevented, thereby capable of reducing the effort and cost of work to remove adhering organisms and avoiding negative effects on the marine water environment and the like.SOLUTION: The construction capable of preventing adhesion of marine organisms thereto is used under the sea, or used in potential contact with seawater, and comprises nickel silver which consists of, by mass%: Cu in an amount from 63.0% to 67.0% inclusive; Pb in an amount from 0 or more than 0 to 0.03% inclusive; Fe in an amount from 0 or more than 0 to 0.25% inclusive; Mn in an amount from 0 or more than 0 to 0.50% inclusive; Ni in an amount from 8.5% to 11.0% inclusive; and the remainder consisting of Zn and unavoidable impurities. Further, a layer consisting of the nickel silver of the composition above may be formed on a surface of the structure contacting seawater.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a structure capable of preventing the attachment of living organisms such as underwater shellfish and algae (i.e., marine organisms).

In power plants, chemical plants, etc., seawater is used as cooling water, so piping, etc. are immersed in the sea to take water. Since marine organisms such as shellfish and algae from the sea adhere to these pipes, removal of these marine organisms is carried out regularly, consuming a great deal of labor and expense.
The same applies to buildings, ship shells, piping, and even offshore structures that come into contact with seawater, especially if these structures are coated with paint to prevent shellfish from adhering to them. , the paint will be released into the sea, and large amounts of metal raw materials will be released into the natural world throughout the year, which may have a negative impact on the seawater environment. Furthermore, when repainting the paint, it is necessary to manually remove the currently applied paint and then reapply the new paint, which may pose a health hazard due to the dust generated during the peeling process.

Currently, aluminum brass, titanium, and stainless steel are used as materials for tube sheets of heat exchangers that use seawater as cooling water for the purpose of preventing corrosion (see, for example, Patent Document 1).
However, these materials did not have the ability to prevent marine organisms from adhering to them.

Japanese Unexamined Patent Publication No. 138093/1983

The present invention was made in view of the above circumstances, and it is possible to suppress or even prevent the attachment of organisms such as shellfish and algae in the sea than before, thereby reducing the labor and cost associated with removing attached organisms. It is an object of the present invention to provide a structure capable of preventing the adhesion of marine organisms, which can reduce the amount of water and prevent harmful effects on the seawater environment, etc.

The present inventors have developed a variety of metal materials in order to find metal materials suitable for use in the sea and in areas where sea water is a factor, that is, metal materials that can suppress or even prevent the adhesion of living things such as shellfish and algae. actually carried out the experiment.
As a result, we came up with the chemical composition of nickel silver, which will be described later, as the above-mentioned metal material.
This nickel silver is used as a material for electronic devices such as crystal oscillator cases, transistor caps, volume sliders, and watch dials due to its excellent strength and spring characteristics.It is also used for its beautiful luster and corrosion resistance. It is also widely used in decorative items, Western tableware, wind instruments, etc.
In other words, the present inventors have found a new use for nickel silver, which can prevent marine organisms from adhering to it and is suitable for use in the sea and in areas where seawater can affect it.

A structure capable of preventing the adhesion of marine organisms according to the first invention in accordance with the above-mentioned object is provided with a structure in which, in mass %, Cu: 63.0% or more and 67.0% or less, Pb: 0 or 0. 0.03% or less, Fe: 0 or more than 0 and 0.25% or less, Mn: 0 or more than 0 and 0.50% or less, Ni: 8.5% or more and 11.0% or less, the remainder A nickel silver layer consisting of Zn and unavoidable impurities is formed.

A structure capable of preventing the adhesion of marine organisms according to a second invention in accordance with the above object is used in the sea or in a state where it can come into contact with seawater, and has Cu: 63.0% or more in mass %67 .0% or less, Pb: 0 or more than 0 and 0.03% or less, Fe: 0 or more than 0 and 0.25% or less, Mn: 0 or more than 0 and 0.50% or less, Ni: 8.5% 11.0% or less, with the remainder being nickel silver consisting of Zn and unavoidable impurities.

The above-mentioned nickel silver is a Cu-Ni-Zn alloy, and corresponds to alloy number C7451 specified in JIS H3110 (2018).

The structure capable of preventing the adhesion of marine organisms according to the present invention can be produced by forming a layer of marine silver having the above-described chemical composition on the surface of the structure that comes into contact with seawater, or By constructing the structure itself that is used in a state where it can come into contact with nickel silver having the chemical composition described above, it is possible to suppress and even prevent the attachment of organisms such as underwater shellfish and algae to a greater extent than before. .
This makes it possible to reduce the frequency of maintenance work compared to conventional methods, which reduces the labor and cost associated with removing attached organisms.It also reduces the negative impact on the seawater environment, etc. due to not using paints to prevent attached organisms. It can be prevented.

It is a photograph showing the state of adhesion of shellfish to the test piece according to the example and the test piece according to the comparative example that were immersed in the sea. It is a photograph which shows the state of adhesion of shellfish before and after immersing a test piece in the sea according to a conventional example. It is a photograph showing the state of adhesion of shellfish to a test piece according to a conventional example after being immersed in the sea.

Next, embodiments embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention.
A structure capable of preventing the attachment of marine organisms according to an embodiment of the present invention is capable of suppressing and even preventing attachment of marine organisms such as shellfish and algae than before, and is capable of suppressing and even preventing the attachment of marine organisms such as shellfish and algae, and is capable of suppressing and even preventing the attachment of marine organisms such as shellfish and algae. It is suitable for use in
This will be explained in detail below.

Structures are structures to which organisms such as shellfish and algae from the sea adhere, or are likely to adhere, due to the influence of the sea and seawater. Specifically, power generation plants (components such as joints (flanges and elbows), piping, wire rods, etc.), chemical plants, ship components (bottoms, screws, rudders, etc.), offshore structures (offshore wind power generation equipment), etc. There is.
A layer of nickel silver (nickel silver layer) is formed on the surface of this structure that comes into contact with seawater. The nickel silver layer is formed by plating nickel silver on the surface of the object that will come into contact with seawater, for example, by electroplating or hot-dip plating, by coating nickel silver by thermal spraying, or by coating nickel silver on the surface of the object that will come into contact with seawater. It can be formed by processing and pasting a thin plate material (with a thickness of about 4 mm or less).
Further, the structure itself (itself) can be made of nickel silver (the structure can be formed by processing, casting, etc. using nickel silver).

Nickel silver is mass%, Cu (copper): 63.0% or more and 67.0% or less, Pb (lead): 0 or more than 0 and 0.03% or less, Fe (iron): 0 or more than 0. 0.25% or less, Mn (manganese): 0 or more than 0 and 0.50% or less, Ni (nickel): 8.5% or more and 11.0% or less, the balance being Zn (zinc) and inevitable impurities. It is a Cu-Ni-Zn alloy consisting of, for example, an alloy corresponding to alloy number C7451 specified in JIS H3110 (2018).
This nickel silver is rich in flexibility and bendability, has relatively good corrosion resistance, and is superior to brass in mechanical properties such as tensile strength. Generally, as Ni increases, the springiness increases, as Zn increases, the strength increases, and as Cu increases, the malleability increases. Also, like general metals, it is a conductor.
As a result of actually conducting various experiments, the present inventors newly discovered that the above-mentioned nickel silver also has the function of suppressing and even preventing the adhesion of marine organisms.

Next, examples performed to confirm the effects of the present invention will be described.
(Test 1)
The test pieces of Examples and Comparative Examples were immersed in the sea, and the results of checking the state of adhesion of shellfish will be explained with reference to FIG.
Here, an experiment was conducted by immersing four types of test specimens in seawater at Port A and Port B, which have different seawater conditions. The test pieces used were nickel silver with alloy number C7451 mentioned above as an example (the left end of the upper diagram in Figure 1 and the lower diagram in Figure 1), and brass castings (specified in JIS H5120 (2016)) as a comparative example. Brass casting type 1 (alloy code CAC201): second and third from the left in the top diagram of FIG. 1) and nickel silver with alloy number C7701 (right end in the top diagram of FIG. 1) were used, respectively. This nickel silver with alloy number C7701 is an alloy specified in JIS H3130 (2018), and in mass %, Cu: 54.0% to 58.0%, Pb: 0 or more than 0.03 % or less, Fe: 0 or more than 0 and 0.25% or less, Mn: 0 or more than 0 and 0.50% or less, Ni: 16.5% or more and 19.5% or less, the balance being Zn (zinc) It is an alloy (nickel silver for springs) containing less Cu and more Ni than the nickel silver with alloy number C7451 used as an example.

As shown in the upper diagram of Figure 1, no shellfish was observed on the test piece of the example even after 2 years of immersion, but the test piece of the comparative example, the brass casting, and the It was confirmed that soil, algae, and barnacles were attached to the white surface.
In addition, as shown in the lower diagram of FIG. 1, when the test piece of the example was immersed in different seawater, no shellfish adhesion was observed even after two years had passed since the immersion.
In this way, the test pieces of the examples were able to suppress and even prevent the attachment of organisms such as underwater shellfish and algae compared to the test pieces of the comparative examples. It has been found that by using a certain nickel silver with alloy number C7451, very good results in preventing the adhesion of marine organisms can be obtained compared to the comparative example of nickel silver with alloy number C7701.

(Test 2)
The results of confirming the adhesion speed of shellfish by immersing metal materials conventionally used in environments where they come into contact with seawater into the sea will be explained with reference to FIGS. 2 and 3.
Here, an experiment was conducted by immersing five types of test specimens in seawater at Port A. The test pieces were made of copper (the left end before the start of immersion and after 18 days in Figure 2, and the left end in the upper diagram of Figure 3), and those made of four common brass-based materials (Figure 2). 2, and the left end of the upper diagram of FIG. 3).
When five types of test specimens were immersed in seawater under the conditions shown in the upper diagram of Figure 2, despite the winter season when the seawater temperature was low, shellfish appeared after 18 days, as shown in the lower diagram of Figure 2. Adhesion occurred. Furthermore, as shown in the upper diagram of FIG. 3, further adhesion of shellfish was observed on all test pieces after two months had passed. The middle and lower figures in FIG. 3 are enlarged photographs of the test piece made of brass-based material in the upper figure.

Therefore, it was confirmed that the structure capable of preventing the attachment of marine organisms of the present invention can suppress or even prevent the attachment of organisms such as shellfish and algae in the sea than before.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the configuration described in the embodiments described above, and the matters described in the claims are as follows. It also includes other embodiments and modifications that may be considered within the scope. For example, it is also within the scope of the present invention to configure a structure capable of preventing the adhesion of marine organisms of the present invention by combining some or all of the above-described embodiments and modifications.
In the above embodiments, examples of structures include power plants, chemical plants, ship components, and offshore structures, but structures that are used underwater or in a state where they can come into contact with seawater If so, there are no particular limitations.

The structure capable of preventing the attachment of marine organisms according to the present invention can suppress or even prevent the attachment of marine organisms such as shellfish and algae in the sea compared to conventional structures. This makes it possible to reduce the labor and cost associated with removing attached organisms, and also to prevent adverse effects on the seawater environment and the like due to non-use of paint for preventing attached organisms.

Claims (2)

On the surface in contact with seawater, in mass%, Cu: 63.0% or more and 67.0% or less, Pb: 0 or more than 0 and 0.03% or less, Fe: 0 or more than 0 and 0.25% or less, It is characterized by the formation of a nickel silver layer containing Mn: 0 or more than 0 and 0.50% or less, Ni: 8.5% or more and 11.0% or less, and the remainder consisting of Zn and inevitable impurities. Structures that can prevent marine organisms from adhering to them. Used in the sea or used in a state where it can come into contact with seawater, Cu: 63.0% or more and 67.0% or less, Pb: 0 or more than 0 and 0.03% or less, Fe: 0 or more than 0 and 0.25% or less, Mn: 0 or more than 0 and 0.50% or less, Ni: 8.5% or more and 11.0% or less, and the balance consists of Zn and inevitable impurities. A structure capable of preventing the adhesion of marine organisms, characterized in that: