JP2001078615A - Iron ion supplying member and man-made gathering-place for fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject member as an assembly of 2 types of steel materials different from each other in chemical composition, formed in a short time into an algae ground on which fish and shellfish grow in a coastal area, allowing the iron ions it contains to effectively elute out, capable of solving the algae blighting phenomenon in a short time, and useful as an excellent man-made gathering-place for fish and shellfish. SOLUTION: This iron ion supplying member is an assembly of 2 types of steel materials 1 and 2 different from each other in chemical composition, satisfying the formula [C]1+2[S]1) [C]2+2[S]2)>=0.10 ([C]1: carbon content of the steel material 1, [S]1: sulfur content of the steel material 1, [C]2: carbon content of the steel material 2, and [S]2: sulfur content of the steel material 2), and is obtained by bringing the steel materials 1 and 2 into electrically contact with each other. It is preferable to use the steel material 2 as the structural member which sustains strength and rigidity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fishing reef, and more particularly, to an artificial steel reef made of steel, in which a seaweed bed, which is a breeding ground for seafood in the coastal waters, can be created in a very short time.

[0002]

2. Description of the Related Art In the sea, there are seaweed beds, which are useful breeding grounds for fish and shellfish, and these are good natural reefs. However, in recent years, the phenomenon of so-called "iso-yake" in which seaweed beds disappear has been increasing. Therefore, a method has been adopted in which artificial reefs are installed in the sea and seaweeds are propagated on the artificial reefs.
As artificial fishing reefs, concrete submerged in the sea was mainly used as a substrate for attaching seaweed. However, in such artificial artificial reefs made of concrete,
It took several years to 10 or more years for the fish to become effective as a reef because the components that had an adverse effect on organisms were likely to flow out as the concrete melted, and lacked immediate effectiveness.

[0003] On the other hand, in recent studies on rocky shores, deficiency of iron ions flowing in from rivers is considered to be a main cause of rocky shores.
An artificial steel reef made of steel is considered.

For example, in Japanese Patent Application Laid-Open No. 4-108327,
On each side of the frame composed of truncated pyramids with rebar,
A horizontal bar is extended with a reinforcing bar, and a vertical bar for reinforcement is further attached so as to be orthogonal to the bar. ing. The technology described in JP-A-4-108327 is
It is a proposal for the structure of a fish reef frame.However, when steel structures are immersed in seawater, the steel material corrodes and supplies an appropriate amount of iron into the seawater. According to the report, zooplankton will increase and food will be abundant. However, Japanese Patent Laid-Open No. 4-10
In the technology described in Japanese Patent No. 8327, there is no technical idea of actively dissolving iron ions, and there is a problem that the elution rate of iron ions is left to the natural and the elution rate of iron ions is low.

To solve such a problem, Japanese Patent Laid-Open No. 6-206804
Japanese Patent Application Publication No. JP-A-2005-64131 has a block made of cellular concrete in which iron oxide and a foam base material are mixed in cement, and a hollow portion is formed in the block, and the hollow portion has an opening on the block surface. The reef structure is filled with iron or a metal with a higher potential than iron and iron, for example, a mixture of graphite and activated carbon, and then immersed in the sea with iron or mixed metal filled in the hollow of the reef structure. -Type fish reef structure, three iron-filled fish reef structures with hollows filled with iron are juxtaposed, and the iron-filled fish reef structure located in the center and the iron-filled fish reef structures arranged on the left and right sides Change the electrical polarity with the object at regular intervals, or arrange a metal with a higher potential than iron on the left and right sides of the iron-filled fish reef structure,
A fish reef intended to increase the elution rate of iron ions by electrically connecting an iron-filled fish reef structure and both metals has been proposed. However, in the technique described in Japanese Patent Application Laid-Open No. 6-206804, it is necessary to apply a special processing to a concrete block, and it is structurally complicated, and it is necessary to constantly maintain an energized state. As a result, the manufacturing cost and the maintenance and management cost are increased, leaving a problem in terms of practicality.

As a method for actively controlling iron ions, Japanese Patent Application Laid-Open No. H11-113440 discloses a method in which a noble metal such as copper, stainless steel, titanium, gold, silver, nickel or the like is pasted on a steel pipe. There has been proposed a steel tube fish nest which aims to form a local battery and release iron ions from the steel tube. However, in the technique described in Japanese Patent Application Laid-Open No. 11-113440, the metals to be stuck, such as gold, silver, stainless steel, titanium, and nickel, are extremely much smaller than ordinary steel generally used as fish reefs. There are problems that it is expensive and that stainless steel, which is a relatively inexpensive metal, has low weldability and difficulties in welding and assembling on site.

[0007]

In order to promote the coastal fishery, a large amount of iron ions are efficiently and inexpensively and continuously supplied to the artificial artificial reef made of steel at a low cost, so that the sea can be grilled in a short time. It is strongly desired to eliminate the phenomenon. At the same time, artificial steel reefs are required to have a life span of 30 years or more as a structure.

[0008] The present invention has been developed to meet such a demand.
An object of the present invention is to provide an excellent steel artificial reef which can maintain a long life of about one year and can supply iron ions to seawater at extremely low cost.

[0009]

Means for Solving the Problems In order to achieve the above object, the present inventors have intensively studied measures for supplying iron ions to seawater at low cost. As a result, the inventors of the present invention, the chemical composition of steel, which has not been focused on at all,
In particular, almost no cost increase as an alloy component,
Alternatively, attention was paid to C and S, which are elements whose refining costs are rather reduced by containing them. And (C + 2)
S) When two types of steel materials whose amounts satisfy a specific relationship are electrically contacted and immersed in the sea, the elution of iron ions from the steel materials is promoted, and moreover, a large amount of iron ions can be stably inexpensively and stably introduced into the sea. I found that it would be possible to supply.

Further, the present inventors have proposed such (C +
2S) When two types of steel materials satisfying a specific relationship are electrically contacted, iron melts in one of the steel materials (a steel material having a large amount of (C + 2S)), and a large amount of iron ions are supplied. On the other hand, it has been found that the other steel material (a steel material having a small amount of (C + 2S)) suppresses the dissolution of iron. Steel material in which dissolution of iron is suppressed (steel material with a small amount of (C + 2S))
, As a structural member that maintains strength and rigidity,
Structure with low corrosion and long life (steel artificial reef)
It is thought that it can be.

The present invention has been completed based on the above findings.

[0012] That is, the present invention provides a method for preparing a compound having different chemical components.
A member assembled with various types of steel materials 1 and 2;
Content [C] ₁ , S content [S] _1, and C
The content [C] ₂ and the S content [S] ₂ are represented by the following formula (1): {[C] ₁ +2 [S] ₁ }-{[C] ₂ +2 [S] ₂ } ≧ 0.10 1) (However, [C] ₁ , [S] ₁ : C and S contents of steel material 1 (wt%), [C] ₂ and [S] ₂ : C and S contents of steel material 2 (wt%)) And the steel material 1 and the steel material 2 are in electrical contact with each other.

Further, the present invention provides a steel material 1 having a C content [C]
₁ , S content [S] ₁ , C content [C] _{2 of} steel material ₂ ,
The S content [S] ₂ satisfies the above expression (1), and the iron ion supply member in which the steel material 1 and the steel material 2 are in electrical contact is disposed as at least a part of the member. It is an artificial reef characterized by being constructed.

[0014] The present invention also provides a method for reducing the number of chemical components.
Artificial reef constructed by assembling two types of steel materials 1 and 2
And the C content [C] of the steel material 1₁, S content
[S] ₁And the C content of steel 2 [C]_Two, S content
[S]_TwoSatisfy the expression (1), and the steel material 1
And the steel material 2 are electrically contacted.
It is an artificial reef, and in the present invention,
It is preferable to dispose it as a structural member responsible for rigidity.
New

The steel material referred to in the present invention is smelted by a commonly known smelting method such as a converter and an electric furnace, cast into a rolled material such as a slab by a continuous casting method, and then subjected to hot rolling. It is manufactured and includes a hot-rolled steel sheet, a hot-rolled H-section steel, a hot-rolled steel bar, etc., and further includes all steel materials satisfying the above-mentioned formula (1), such as as-cast steel materials.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A member for supplying iron ions according to the present invention comprises:
This is a member in which steel materials 1 and 2 having different chemical components are assembled and brought into an electrically contacting state. In the present invention, the shape of this member is not particularly limited. The shape may be appropriately determined according to, for example, a desired shape of the reef.

In the member of the present invention, of the chemical components of the steel material 1 and the steel material 2, the respective C content and S content are as follows (1).
Formula {[C] ₁ +2 [S] ₁ }-{[C] ₂ +2 [S] ₂ } ≧ 0.10 (1) (However, [C] ₁ , [S] ₁ : C and S content of steel material 1 Steel material 1 and steel material 2 are selected, assembled, and contacted so as to satisfy the amount (wt%), [C] ₂ , [S] ₂ : C and S contents (wt%) of steel material 2). State. The steel material 1 and the steel material 2 may be assembled as long as there is a portion where they are electrically in contact with each other. The method is not particularly limited, but it is preferable to perform welding or bolt fixing.

When the member in such a state is immersed in seawater, the steel material 1 having a large amount of (C + 2S) becomes the cathode side, a local cell is formed, the dissolution of iron is promoted, and a large amount of iron ions is contained in the seawater. Supplied to On the other hand, in the steel material 2 having a small amount of (C + 2S), the dissolution of iron is rather suppressed. By bringing steel materials having different chemical components into contact with each other as in the present invention, iron ions are eluted more than simply increasing the surface area to twice as compared with the case where steel materials having the same component are brought into contact.

Usually, in steel, C is a carbide such as Fe ₃ C,
S is present as a sulfide such as MnS, and it is considered that when the formula (1) is satisfied, pitting corrosion locally occurs around these precipitates, and the dissolution of iron is promoted. Steel material 1
And the C and S contents of the steel material 2 do not satisfy the expression (1),
That is, {[C] ₁ +2 [S] ₁ }-｛[C] ₂ +2
When [S] ₂未 満 is less than 0.10, a remarkable increase in the cathodic reaction does not occur, so that the elution of iron ions in seawater is small. From the viewpoint of the elution rate of iron ions, it is preferable that {[C] ₁ +2 [S] ₁ }-{[C] ₂ +2 [S]
₂ 0.2 is 0.2 or more.

Although the C content of steel is generally determined in consideration of the strength and toughness of the steel, the C content is reduced during the smelting process with almost no increase in production cost. It is possible to control. The S content is ppm
Except for a special case where the amount is reduced to the extremely low S region on the order, the amount can be controlled without increasing the manufacturing cost as in the case of C. In the present invention, the chemical components of the steel material other than C and S are not particularly limited.

A member in which two kinds of steel materials satisfying the above formula (1) are assembled and brought into an electrically contacting state can supply a large amount of iron ions not only in seawater but also in freshwater, This has the effect of promoting the growth of algae that feed on and promoting the growth of aquatic organisms.

Further, such a member for supplying iron ions is
It is preferable to provide the steel artificial reef as at least a part of the artificial reef. As a result, a large amount of iron ions are continuously supplied to the seawater, the generation of phytoplankton and the growth of algae are promoted, and a fishery gathering place or a breeding place can be provided as an excellent artificial reef.

In the steel artificial reef according to the present invention, the arrangement of the members in which the two types of steel materials 1 and 2 satisfying the above-mentioned expression (1) are arranged in a state where the steel materials 1 and 2 are in electrical contact. , And is not limited basically. In order to make the life of the structure longer, the dissolution of iron is suppressed, and the steel material 2 with a small amount of (C + 2S) is placed in a portion such as a column or a main beam, which is responsible for strength and rigidity. It is preferred to do so. On the other hand, it is preferable that the steel material 1 having a large amount of (C + 2S) is mainly disposed at a place where the demand for strength and rigidity is relatively small as a feeder of iron ions, but it is not always necessary to assign the strength and rigidity as a fishing reef structural member. Absent. For example, the present invention can be applied to a steel material 1 having a large amount of (C + 2S) as an accessory of a steel artificial reef, and only electrically contacting a steel material 2 having a small amount of (C + 2S), and simply acting as a supplier of iron ions. The effect of is fully exhibited.

FIG. 1 shows a structure of a steel artificial reef according to the present invention.
An example is shown schematically. Note that the present invention is not limited to this.

In FIG. 1, of the two types of steel materials satisfying the above equation (1), the steel material 2 having a small amount of (C + 2S) is used as the column 11a,
11b, 11c, 11d, and main beams 12a, 12b, 12c,
It is placed at 12d to ensure the strength and rigidity of the structure. On the other hand, the steel material 1 having a large amount of (C + 2S) is replaced with the horizontal beams 13a and 15a and the vertical beams 14a, 14b and 14c, which share less strength and rigidity.
, 14d are joined to the steel material 2 by welding or the like and arranged in an electrically contacting state.

With such a structure, the steel 1
Is mainly responsible for the role of an iron ion supplier, and continues to supply iron ions. The steel material 2 is suppressed in dissolution of iron, is responsible for strength and rigidity, and can have a long life as a structure.

In the artificial reef of the present invention, the foundation may be reinforced with concrete, or stones or the like may be loaded into the reef. Needless to say, these are necessary for making a reef and do not impair the effects of the present invention.

In the present invention, it is preferable that the artificial reef is constructed using only two types of steel materials 1 and 2 as described above, but all the members are the two types of steel materials 1 and 2 described above. There is no need to arrange at least one place where the steel material 1 and the steel material 2 are brought into electrical contact, and the initial purpose can be achieved.

[0029]

EXAMPLE Two types of steel materials 1 and 2 were selected from hot-rolled steel sheets having the chemical components shown in Table 1, and a test material (6 mm thick × 175 mm width × 300 mm) was selected from the selected steel materials 1 and 2. (Length) was collected, and in the combinations shown in Table 2, the entire periphery was joined by welding to produce a member in an electrically contacting state.

These members were immersed in artificial seawater at 25 ° C., and the elution rate of iron ions from the steel material 1 was measured. In addition,
The elution rate of iron ions from the steel material 1 was converted into an iron ion elution rate by measuring the weight loss of the member after one year and dividing by the surface area.

Table 2 shows the results. The elution rate ratio shown in Table 2 means the ratio between the elution rate of iron ions from steel material 1 in each member and the elution rate of iron ions from steel material 1 in member No. 3. Material No. 3 is made of ordinary material (SS 400
This is a conventional example in which materials are joined together.

[0032]

[Table 1]

[0033]

[Table 2]

In the present invention, the elution rate ratio of iron ions is 5.
7 or more and a conventional example of joining ordinary materials (member No. 3)
The elution of iron ions is remarkably promoted as compared with the case of the present invention. On the other hand, in the comparative example out of the range of the present invention, 1.
It is about 7 times, and no remarkable promotion of iron ion elution is seen.

According to the present invention, by contacting steel materials having different chemical components so as to satisfy the above-mentioned formula (1), it is possible to simply contact ordinary steel materials having the same components to increase the surface area of the steel material more than twice. Can be.

If steel materials having different chemical components are brought into contact with each other and disposed on a reef or the like, or if steel materials having different chemical components are brought into contact to form an artificial reef, it is advantageous in seawater or freshwater. As a result, iron ions can be supplied to the fish and the growth of algae serving as food for aquatic organisms including fish is promoted, so that the proliferation and aggregation of aquatic organisms such as fish and shellfish can be expected.

[0037]

As described above, according to the present invention,
Iron ions are effectively eluted, and the shore burning phenomenon can be eliminated in a short period of time. As an excellent artificial reef, fishery resources can be easily secured and industrially significant effects can be expected.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the configuration of an artificial reef according to one embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Michio Komatsubara, Inventor 1-chome, Kawasaki-dori, Mizushima, Kurashiki-shi, Okayama Pref. Inside the Mizushima Works, Kawasaki Steel Corp. (72) Mineo Muraki, 1-Mizushima Kawasaki-dori, Kurashiki-shi, Okayama Chome (without address) Mizushima Works, Kawasaki Steel Corporation (72) Inventor Katsuhiro Takebayashi 1-chome, Mizushima, Kawasaki-dori, Kurashiki City, Okayama Prefecture (without address) Mizushima Works, Kawasaki Steel Corporation (72) Koji Hanaoka Okayama Prefecture 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi (No. 1) Mizushima Works, Kawasaki Steel Co., Ltd. (72) Inventor Takashi Kono 1-chome, Mizushima-Kawasaki-Dori, Kurashiki-shi, Okayama Prefecture (No. 1) Mizushima Works, Kawasaki Steel Co., Ltd. Reference) 2B003 AA01 BB02 BB04 DD02 EE04

Claims (4)

[Claims] 1. A member in which two types of steel materials 1 and 2 having different chemical components are assembled, wherein a C content [C] ₁ and an S content [S] ₁ of the steel material ₁ and a C content of the steel material 2 are included. The iron ion, wherein the content [C] ₂ and the S content [S] ₂ satisfy the following expression (1), and the steel material 1 and the steel material 2 are in an electrically contacting state. Supply member. Note {[C] ₁ +2 [S] ₁ }-{[C] ₂ +2 [S] ₂ } ≧ 0.10 (1) where [C] ₁ , [S] ₁ : C and S content of steel material 1 (Wt
%) [C] ₂ , [S] ₂ : C, S content of steel 2 (wt%) 2. An artificial reef comprising the iron ion supplying member according to claim 1 as at least a part of the member. 3. An artificial reef constructed by assembling at least two types of steel materials 1 and 2 having different chemical components, wherein the steel material 1 has a C content [C] ₁ and an S content [S] _1.
And C content [C] ₂ and S content [S] _{2 of} the steel material 2,
Satisfies the following expression (1), and the steel material 1 and the steel material 2 are in electrical contact with each other. Note {[C] ₁ +2 [S] ₁ }-{[C] ₂ +2 [S] ₂ } ≧ 0.10 (1) where [C] ₁ , [S] ₁ : C and S content of steel material 1 (Wt
%) [C] ₂ , [S] ₂ : C, S content of steel 2 (wt%) 4. The artificial reef according to claim 3, wherein said steel material 2 is provided as a structural member for providing strength and rigidity.