JPH111734A - Seawater corrosion resisting material for antisticking of marine living things - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a seawater corrosion resisting material for antisticking of marine living things, superior in strength and corrosion resistance than the conventional materials. SOLUTION: This material has a composition consisting of, by weight ratio, 2-<12% Al, 1.5-<20% Cr, 30-<80% Cu, 0.3-<10% of Ni or/and Mo, <0.2% C, <0.25% Si, <2% Mn, <0.05% P, <0.005% S. 0.1-<1%, independently or in combination, of Nb, Ti, or V, and the balance iron with inevitable impurities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seawater desalination system pipe, a heat exchanger pipe, and other marine facilities, etc., which have a marine organism adhesion preventing property which can be used alone or in combination with other materials. It relates to an excellent seawater resistant material.

[0002]

2. Description of the Related Art In recent years, various structures have been installed in the sea to effectively utilize various resources and energy existing in the sea. Also, in the energy field, there are many cases where seawater is used as cooling water for power plants, and many pipes for heat exchangers and the like are used for this purpose. In the Middle and Near East, a large-scale seawater desalination plant is operating for desalination from seawater.

[0003] In any of these devices and facilities, the biggest problem is the adhesion of marine organisms such as barnacles, crows and seaweeds. In other words, in the case of a floating offshore structure, the buoyancy is reduced by these marine organisms, in ships, fuel consumption increases due to a decrease in navigation speed, and in the case of a heat exchanger, the heat transfer coefficient decreases. It raises various serious problems.

As a material for solving such a problem,
Conventionally, copper and copper alloys have been used. In both cases, the toxicity of the eluted Cu ions is utilized, but it cannot be said that the corrosion resistance and strength to maintain the function as a structural material are not sufficient even in a variety with a sufficient amount of elution required for antifouling properties. It is the current situation. For example, although cupronickel obtained by adding Ni to Cu is used alone or as a composite material with steel having excellent strength, strength alone is low,
In addition, the antifouling property is not sufficient, the corrosion and strength of the interface are not sufficient in the case of the composite material, and the high cost is a problem.

On the other hand, JP-A-57-5837, JP-A-59-263520, and JP-A-61-2
JP-A-35527 and JP-A-62-151538 propose a copper alloy in which the balance between corrosion and antifouling properties is controlled by adding mainly Ni, Mn or the like to Cu. However, since these materials are copper alloys, there is a problem that the strength is still poor.

Japanese Unexamined Patent Publication (Kokai) No. 6-100968l discloses a material in which corrosion is suppressed by adding Al to an alloy composed of two phases of Cu and high-strength Fe having antifouling properties. However, it was found that in this material, the corrosion resistance of the Fe phase was not sufficient, and rust was generated in the long term and the antifouling property was lost. That is, a material having both antifouling properties and strength, and more excellent corrosion resistance, by an alloy made of two phases of Cu and high-strength Fe having antifouling properties has been desired.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a novel seawater-resistant material excellent in antifouling properties, strength and corrosion resistance, which can economically prevent the adhesion of marine organisms, especially the adhesion of barnacles. The purpose is to:

[0008]

In order to achieve the above-mentioned object, the present invention provides a method for manufacturing a semiconductor device comprising: Al: 2% or more and less than 12%;
r: 1.5% or more and less than 20%, Cu: 30% or more and 80%
Less than 0.3% with Ni or Mo alone or in combination
Not less than 10%, C: less than 0.2%, Si: 0.25%
, Mn: less than 2%, P: less than 0.05%, S: 0.
It is a seawater resistant material containing less than 005%, the balance being iron and unavoidable impurities, for preventing marine organisms from adhering. In addition, Al: 2% or more and less than 12%, Cr: 1.5% or more and 20% by weight. , Cu: 30% or more and less than 80%, Ni or Mo alone or in combination 0.3% or more and less than 10%, C: less than 0.2%, Si: less than 0.25%, Mn:
Less than 2%, P: less than 0.05%, S: less than 0.005%, 0.1 or more of Nb, Ti or V alone or in combination.
This is a seawater resistant material for preventing marine organisms from adhering, containing at least 1% and less than 1%, with the balance being iron and unavoidable impurities.

Hereinafter, the present invention will be described in detail. The features of the present invention are:
Cu—F that cannot be produced by a normal process because cracks occur by containing Al of 2% or more and less than 12%
e) The hot workability of the two-phase alloy was improved and the corrosion resistance was improved at the same time. Ni or Mo was used alone or in combination.
By containing 3% or more and less than 10%, the corrosion resistance due to seawater is remarkably improved. Further, by containing Nb, Ti or V alone or in combination with 0.1% or more and less than 1%, workability and corrosion resistance are improved. That is, the strength was improved without loss.

The reasons for limiting each component in the present invention will be described below. Al is an important element that facilitates production by hot working and improves corrosion resistance. This effect is 2
If it is less than 12%, it may not be expected, and if it is more than 12%, it may form an intermetallic compound and become brittle, thereby impairing hot workability.

[0011] Cr is an element that improves the corrosion resistance of the Fe phase and also improves the workability. In order to obtain the effect, 1.5% or more is required, and the reason for setting the content to less than 20% is that embrittlement is recognized on the contrary.

The reason why the content of Cu is set to 30% or more and less than 80% is that 30% is used for securing the antifouling property for preventing the adhesion of marine organisms.
This is because the above is necessary, and if it is 80% or more, the strength is not sufficient.

The reason that Ni or Mo is used alone or in combination with 0.3% or more and less than 10% is that
In order to improve the corrosion resistance of the phase, 0.3% or more is necessary. However, when 10% or more is added, the workability is significantly reduced,
And it is not economical.

Each element of C, Si, Mn, P and S is Fe
In order to ensure the strength and corrosion resistance of the phase or to pay attention when using an inexpensive Fe raw material, its components are limited for the following reasons. The reason for setting C: less than 0.2% is that when C is 0.2% or more, embrittlement occurs.
Si: Less than 0.25% is because Si is 0.25%
This is because the hot workability is significantly reduced in the above.

The reason that Mn is less than 2% is that Mn is 2%.
This is because embrittlement occurs. The reason for setting P: less than 0.05% is that if P is 0.05% or more, hot workability and corrosion resistance deteriorate. The reason for setting S: less than 0.005% is that if S is 0.005% or more, hot workability and corrosion resistance deteriorate.

The reason that Nb, Ti or V is used alone or in combination with 0.1% or more and less than 1% is that 0.1% or more is necessary in order to improve the strength of the Fe phase.
This is because the above addition causes embrittlement.

According to the present invention, the material composed of the above chemical components is melted in a converter, an electric furnace, or the like, and then subjected to a process of ingot and lumping, or a process such as rolling after continuous casting. It is used as a plate, pipe, wire, or rod. Also, it can be used after being formed into a shape close to the final shape by casting.

[0018]

EXAMPLES Table 1 shows the components and properties of the material of the present invention and the comparative material. In each case, alloys having the components shown in Table 1 were melted in a vacuum melting furnace to form a 50 kg ingot, which was then hot-rolled into a 10 mm thick plate.

For examining the antifouling property, a test piece having a width of 50 mm, a length of 100 mm and a thickness of 2 mm was sampled from the center of the rolled plate, and the entire surface was mechanically polished and degreased to obtain a sample. This sample was completely immersed in seawater 1 m below the sea surface for one year, and the state of attachment of marine organisms such as barnacles was observed. Table 1 shows the results.
The corrosion resistance was determined by observing the state of rust of the same sample immersed in seawater for one year. The results are also shown in Table 1. Further, the tensile strength was investigated by processing a tensile test piece from a rolled plate and conducting a test according to the method specified in JIS Z 2241. Table 1 shows the results.

[0020]

[Table 1]

From Table 1, it can be seen that the material of the present invention is superior to the comparative material in antifouling properties for preventing marine organisms from adhering, and is superior in both corrosion resistance to seawater and strength.

[0022]

According to the present invention, it is possible to omit maintenance which requires a great deal of labor and cost due to the attachment of marine organisms.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C22C 38/00 302 C22C 38/00 302Z 38/58 38/58

Claims (2)

[Claims] 1. Al: 2% or more and less than 12% by weight,
Cr: 1.5% or more and less than 20%, Cu: 30% or more and 80
%, Less than 0.3 of Ni or Mo alone or in combination
% To less than 10%, C: less than 0.2%, Si: 0.25
%, Mn: less than 2%, P: less than 0.05%, S:
A seawater-resistant material containing less than 0.005%, the balance being iron and unavoidable impurities, for preventing marine organisms from adhering. 2. Al: 2% or more and less than 12% by weight,
Cr: 1.5% or more and less than 20%, Cu: 30% or more and 80
%, Less than 0.3 of Ni or Mo alone or in combination
% To less than 10%, C: less than 0.2%, Si: 0.25
%, Mn: less than 2%, P: less than 0.05%, S:
A seawater-resistant material containing less than 0.005%, Nb, Ti or V alone or in combination, in an amount of 0.1% or more and less than 1%, with the balance being iron and unavoidable impurities.