JP2001247953A - Thermal spray coated member excellent in corrosion resistance, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the early corrosion and wear rate, under a natural environment, of steel structures, such as bridges and towers and drums, which are constructed in heavy industry areas and marine climate areas. SOLUTION: A corrosion preventive sprayed deposit is formed on the surface of a steel structure by using a powder material which has a composition consisting of 1-30 wt.% of free aluminum metal or its alloy and the balance metal component having an electric potential electrochemically equivalent to or nobler than that of carbon steel. Further the deposit is subjected to heating in a heat source for thermal spraying and to heating after film deposition. By this procedure, owing to the exothermic reaction attendant on the formation of an Al intermetallic compound, such as Al-Fex, Al-Nix, Al-Cox and Al-Crx, and the action of the aluminum metal in a molten state, the mutual bonding power of particles constituting the deposit can be improved and pores can be dissipated, and as a result, the thermal spray coated member excellent in seawater resistance can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray-coated member having excellent corrosion resistance against seawater and salt and a method for producing the same, and more particularly, to a method for depositing a metal component having an electrochemically noble potential on a substrate surface. This is a proposal for a technology created based on a completely new concept of forming a coating containing a film and preventing corrosion. The technology of the present invention can also be used as a corrosion-resistant coating for steel structures and industrial machinery members or aluminum and aluminum alloy members constructed in heavy industrial areas, rural areas, and the like.

[0002]

[Prior Art] Used for bridges, building steel frames, tower tanks, etc.
Many of the steel materials that are produced generate red rust in the natural environment.
Wear. In particular, sulfur oxides (SO_x) And nitrogen oxides
 (NO _x) Steel structure constructed in heavy industrial area with high content
The object is strongly corrosive due to acid rain, etc.
Steel structures built in marine weather areas
It is known that corrosion due to water and sea salt particles causes significant wear.
Have been. Therefore, these steel structures usually have
A device designed to control corrosion by applying anti-corrosion surface treatment
Have been A typical example is a coating process or
Are hot-dip galvanizing and hot-dip aluminum
There is.

As another anticorrosion method, there is a method of forming a sprayed coating of zinc, aluminum, or an alloy thereof having an electrochemically low potential on the surface of carbon steel by spraying. For example, JIS H8300 (1999) has been established as thermal spraying of zinc and aluminum and their alloys. The anti-corrosion technology by thermal spraying is based on the fact that the coatings of Zn, Al and their alloys exhibit excellent corrosion resistance in the first place, and that even if the coating is partially worn out and the substrate is exposed, the remaining coatings This is based on the fact that metal has the property of protecting a steel substrate electrochemically (sacrificial anode action). In many cases, the surface of these thermal spray coatings is subjected to a so-called heavy-corrosion treatment for further applying a coating to maintain long-term durability.

[0004] However, in recent steel structures, in addition to those newly constructed, maintenance and inspection of existing steel structures have required enormous manpower and expenses, and the conventional steel structures described above have been required. The fact is that it is no longer possible to deal with corrosion prevention technology for steel structures based on the concept alone.

[0005]

The conventional anti-corrosion technology using a coating applied to a steel structure or a metal spray coating such as Zn or Al has a certain anti-corrosion effect. In the case of a film, since it is porous, it is necessary to perform re-working, and there are also the following problems. (1) Thermal spray coating using Zn, Al and their alloys, which have an electrochemically low potential with respect to the base material, is a method of protecting steel structures by sacrificial anode action. Although the corrosion of the material can be suppressed to some extent, on the other hand, when viewed from the side of the Zn and Al metal coatings, it means that they are quickly worn away, and there is a problem that re-spraying must be performed frequently. (2) Especially in the case of thermal sprayed coating, it is porous, and in areas such as Japan where there are many heavy industries and long shorelines, in addition to the corrosive action of SO _x and NO _x , it is easily affected by salt damage. In addition, there was a problem that the corrosion wear rate of the steel structure was high.

[0006] The main object of the present invention is to provide a method for treating seawater, NO _x , S
And to provide a good spray coating member in durability against corrosive gases, such as O _x. Another object of the present invention is to improve the life of the coating by providing a dense and excellent adhesion thermal sprayed coating, thereby reducing the number of times of reconstructing itself and suppressing the burden and cost of maintenance work. . Still another object of the present invention is to propose a technique for easily and inexpensively manufacturing a spray-coated member having excellent salt water resistance and the like.

[0007]

As a result of earnestly examining the above-mentioned problems of the prior art, it is advantageous to employ technical means based on the following knowledge to solve the problems. all right. (1) Compared to conventional sacrificial anodic action on metal base materials such as carbon steel, this base material has the same or noble potential electrochemically and is particularly excellent in corrosion resistance If a free metal Al or an alloy thereof is contained in a thermal spray coating coated by spraying using this material, excellent corrosion resistance will be exhibited. (2) Low melting metal Al or its alloy is easily melted in a thermal spraying heat source, causes a metallurgical reaction with the coexisting corrosion-resistant metal material, generates an aluminum intermetallic compound, and this reaction involves heat generation. In addition, the temperature at which the substrate is exposed is substantially increased, the mutual bonding force of the particles constituting the coating is improved, and the good adhesion to the carbon steel substrate is exhibited. (3) Due to the above phenomenon (2), the presence of pores peculiar to the thermal sprayed coating is significantly reduced, and for example, the intrusion of seawater or the like serving as a corrosive medium can be effectively prevented. Therefore, even if a small amount of seawater penetrates into the inside through the pores of the coating, unreacted metal Al or its alloy present in a free state in the coating exerts a sacrificial anode effect, and the carbon steel base material and Corrosion of other spray particles is suppressed.

The present invention, which has been developed based on the above findings,
On the surface of the metal substrate, a thermal sprayed anticorrosion film of a corrosion-resistant metal having an electrochemically noble potential equal to or higher than that of the substrate metal is formed. Or 1-30wt aluminum alloy
%, Which is a spray-coated member having excellent corrosion resistance.

In a further preferred form of the present invention, a thermal sprayed anticorrosion coating of a corrosion-resistant metal having a noble potential that is electrochemically equal to or higher than that of the base metal is formed on the surface of the metal base, In addition, the sprayed anticorrosion coating contains 1 to 30 wt% of free metallic aluminum or aluminum alloy.
% Of an Al intermetallic compound formed by a metallurgical reaction between aluminum and the metal material having a noble potential.
It is a spray-coated member excellent in corrosion resistance characterized by containing 3 to 15% by weight.

[0010] The method of the present invention for producing the above-mentioned member comprises the steps of:
At the same time as forming a thermal sprayed anti-corrosion film by spraying a powder material composed of a corrosion-resistant metal having a noble potential equal to or greater than the electrochemically with respect to the base metal included as a balance, a metal in a free state is contained in the film. Aluminum or its alloy
It is characterized by being left in an amount of about 30% by weight.

Another method of the present invention is to provide a method in which a surface of a metal base material has a potential which is electrochemically equal to or higher than metal aluminum or its alloy and the base metal contained as the balance. At the same time as forming a thermal sprayed anti-corrosion film by spraying a powder material composed of a corrosion-resistant metal, 1-30 metal aluminum or its alloy in a free state is contained in the film.
wt.%, and then heat-treating the thermal sprayed anticorrosion film at a temperature higher than the melting point of aluminum to further generate and disperse Al intermetallic compounds in the film.

In the present invention, the metal base material is
If carbon steel, electrochemically equivalent to carbon steel
Or, if the corrosion-resistant metal component showing a noble potential is Ni, Cr, C
Any one or more selected from o, Cu, Ti, Mo and Fe
Consisting of a metal or alloy of
Fe in the film₃Al, FeAl, FeAl₂, FeAl₃, NiAl₃, Ni
₂Al₃, NiAl, Ni₃Al, Co₂Al₉, Co₄Al₁₂, Co₂Al
₅, CoAl, CrAl₇, Cr₂Al₁₁, Cr₄Al₉, Cr₅Al₈You
And Cr₂One or more Al intermetallic compounds selected from Al
It can be said that the preferred embodiment is included.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention focuses on carbon steel as a base material of a steel structure, and has the same electrochemical potential or noble potential as carbon steel on the surface of the carbon steel while simultaneously Forms a thermal sprayed anticorrosion coating mainly composed of a corrosion resistant metal having excellent corrosion resistance. And in the film,
It is characterized by containing 30 wt% of free metal Al or its alloy.

Here, when the base material is carbon steel (SS material), Ni, Ni, etc., which are electrochemically equivalent to or have a noble potential electrochemically equivalent to the corrosion potential (-0.440 V vs. SCE) of this carbon steel.
There are Cr, Co, Cu, Ti, Mo, Fe and the like, and as practical metals, various stainless steels, incoloy alloys, inconel alloys, hastelloy alloys, stellite alloys, Ni-Cr alloys and the like are known. In addition, even if the alloy contains Al like a Kanthal alloy, some Ni-Cr-Al alloys may be completely alloyed with Al or be contained as an intermetallic compound.
(SS material) is a material showing a noble potential with respect to (SS material). In addition,
Pure metals such as Cr and Ti show a lower potential than Fe when there is no oxide film, but in a natural environment, Cr ₂ O ₃ , T
Since an oxide film such as iO ₂ is generated, the potential is higher than that of Fe. Cr contained in incoloy alloys, inconel alloys, various stainless steels, etc. shows the same phenomenon and improves corrosion resistance.

That is, the base metal described above, for example, steel (SS)
Metals and alloys that have a noble potential with respect to (steel) have basically higher seawater resistance than carbon steel, and exhibit stable performance over a long period of time even in a natural environment. However, by spraying these materials,
When a coating is formed on the surface of a carbon steel base material, there are the following problems derived from a porous film which is an essential characteristic of the thermal spraying process. This is because a general thermal spray coating always has pores, and has a coating structure in which seawater, rainwater, and the like easily enter the inside. For this reason, for example, seawater that has penetrated the inside of the film exerts an electrolytic action,
(High potential) thermal spray coating becomes the cathode,
(Low potential) carbon steel base material becomes the anode, creating a so-called corrosion battery, which has the basic problem that corrosion of the carbon steel base material progresses as a result of the flow of corrosion current from the anode to the cathode. ing. Therefore, in the present invention, a noble potential means a metal exhibiting a more negative potential (low potential), while a noble potential means a metal exhibiting a more positive potential (high potential). It shall be.

Further, in a general thermal spray coating, the thermal spray material exhibits a structure in which the fine particles are flattened when flying in a thermal spray airflow and laminated on a base material, and each fine particle is heated and melted. At this time, since it is oxidized by the air in the spraying atmosphere, an oxide film always forms on the surface. Therefore, the flattened laminated particles have a film configuration in which they are in contact with each other via the oxide film. For this reason, there is a disadvantage that the bonding force with the carbon steel base material as well as the bonding force between the laminated particles is weakened. In addition, the oxide film on the surface of the flattened laminated sprayed particles has poor ductility and does not fuse like metal, which causes the formation of minute voids, which is the path of internal penetration of an aqueous solution such as seawater. It has become.

Such a phenomenon also occurs in sprayed coatings of Zn, Al and their alloys. However, since these metal sprayed coatings originally have an electrochemically lower potential (lower potential) than carbon steel, Even if seawater has entered,
Since the reverse corrosion current flows through the carbon steel base material as the cathode, a corrosion prevention action is provided. Therefore, many of the current anticorrosion coatings are relatively low relative to substrates such as Zn and Al.
(Low potential) It is common to apply a thermal spray coating of metal. The so-called present invention intends to prevent corrosion by coating a metal or alloy having a potential (high potential) electrochemically more noble than carbon steel, and forming a thermal sprayed anticorrosion film as described below. It can be called technology.

That is, the technology according to the present invention is to use a metal or alloy which is originally considered to be sacrificed to be a coating material, and more specifically, to electrochemically equal or so-called carbon steel. Even if the metal material shows a noble potential, if the metal itself has excellent corrosion resistance, in some cases, it is possible to prevent the influence of pores in the fate spray coating, which is a fate. is there. First, metal Al is added to the thermal sprayed material, and after thermal spraying, the metal Al in a free state is dispersed and dispersed in the coating, thereby sealing the pores with free metal Al. In addition, it is to improve the mutual bonding force of the fine particles constituting the thermal spray coating and the bonding force with the carbon steel base material. In addition,
Thermal spray coatings formed in accordance with the present invention are characterized by unreacted residual metal
Since Al penetrates into the pores and seals, a high-density film is formed. That is, the density of the film according to the present invention is as low as 0.2 to 0.5 as compared with the porosity of the conventional film of 1 to 3%,
In particular, there is a feature that through pores disappear.

Secondly, after the thermal spray coating is formed, if the metal Al, which is independently dissolved in the coating, is contained in a free state, the free metal Al is contained in the coating. It acts as a so-called anode for the electrochemically noble metal particles and the carbon steel base material, and serves as a sacrificial anode to protect the metal particles and the carbon steel base material.

For example, the surface of SUS 304 stainless steel particles
Sprayed metal coated with metal Al using granulation method
When a film is formed using a material, the following reaction occurs. (1) In the thermal spray heat source, first, metal Al with a low melting point on the surface is melted.
As well as the stainless steel particles inside it
Respond. (2) By the above metallurgical reaction, Fe₃Al, FeAl, FeAl₂, Fe
Al₃, NiAl₃, Ni₂Al ₃, NiAl, Ni₃Al, CrAl₇, Cr₂
Al₁₁, Cr₄Al₉, Cr₅Al and Cr₂Between metals such as Al
A compound is formed. All of these reactions are exothermic
Lower the viscosity by raising the temperature of the molten / semi-molten particles.
Let it down. As a result, the molten and semi-molten particles
When colliding with particles, the particles often flatten and stack
Improves bond strength between particles and helps to reduce pores
(The heat generated during the formation of NiAl intermetallic compound
The amount of adiabatic combustion temperature is about 1900K). (3) Thermal spray particles passing through the thermal spray heat source
Reaction (1/100 to 1/1000 second), the reaction in (2) above is complete.
Impacts the surface of the carbon steel substrate without sintering,
All reactions remain non-equilibrium and Al remains unreacted
State, that is, at least a part of the film remains free
Will be done. (4) Since the above-mentioned unreacted metal Al is in a molten state,
It promotes mutual bonding with stainless steel particles and has good fluidity.
It improves the adhesion when colliding with the carbon steel base material.
Let In addition, the pores of the film are affected by the unreacted metal Al.
It will be sealed by entry. (5) Since molten metal Al has a deoxidizing effect,
Suppresses the oxide film formation reaction of stainless steel particles. This means that
Contributes to improvement of the mutual bonding force between stainless steel particles and metallic Al
You. In addition, when the thermal spray material containing Co and Al undergo a metallurgical reaction,
Co₂Al₉, Co₄Al₁₂, Co₂Al₅Or CoAl
Produces intermetallic compounds. (6) Al intermetallic compound generated in thermal spray coating is hard
Therefore, the film has improved wear resistance and blast erosion resistance.
Has the effect of raising.

The thermal spraying material used in the present invention that exhibits an electrochemically equivalent or noble potential includes Ni, Cr, Co, Cu,
Metals such as Ti and Mo and alloys containing these metals as main components, for example, Fe alloys (for example, stainless steel: 18 wt% Cr-
8wt% Ni-residual Fe) and Al alloy (for example, Kanthal alloy: 23wt)
% Cr-6 wt% Al-2 wt% Co-residual Fe) can be used. Note that the Fe alloy and the Al alloy were made of Fe before spraying.
Although Al and Al are dissolved as an alloy or are contained as an intermetallic compound, they are all kinds of metallic materials that show noble behavior to carbon steel. Table 1 shows an example of the measurement of the corrosion potential of these metals and alloy materials.

[0022]

[Table 1]

In the present invention, the amount of free metal Al contained in the thermal spray coating is preferably in the range of 1 wt% to 30 wt%.
If the amount of metal Al is less than 1 wt%, the sacrificial anode effect of the Al does not occur, and the effect of addition is poor. On the other hand, if the amount is more than 30% by weight, the above-mentioned action and effect of the present invention do not become extremely large, so that it is not practical.

The method of adding metal Al is best to use a material coated with metal Al so as to cover the surface of sprayed material particles having a potential that is electrochemically more noble than the base metal. Of course, it may be simply a physical mixture of metal Al particles. Here, as examples of the Al alloy, for example, all the alloys specified in JIS H4000 and JIS H4040 can be used.

Effective methods for forming the above-mentioned sprayed coating having corrosion resistance include the use of powdery sprayed materials such as plasma spraying, flame spraying, high-speed flame spraying, and explosive spraying. Although a suitable thermal spraying method is well suited, the thermal spraying method itself is not particularly limited. The particle diameter of the thermal spray powder material used in the above thermal spraying method is 5 to 5.
The range is preferably 80 μm, particularly preferably 10 to 50 μm. If the particle size is smaller than 5 μm, the fluidity is poor, and if the particle size is 80 μm or more, the heating rate in the thermal spraying heat source is slowed down, so that the production of Al intermetallic compound tends to be difficult to complete smoothly.

[0026]

Example 1 In this example, an experiment was conducted using an alloy having a composition shown in Table 2 as a thermal spray material. All of these sprayed materials and sprayed coatings show an electrochemically noble potential with respect to carbon steel (-0.440 V). It shows excellent corrosion resistance. The coating is formed by adding metal Al to each of the above-mentioned sprayed materials so that the content of metal Al becomes 8 wt% (the surface of the sprayed particles is coated with metal Al by a granulation method), and then by high-speed flame spraying. , 150μ on a carbon steel specimen (SS400 size: width 50 x length 100 x thickness 5mm)
Then, the end face and the back face of the test piece were subjected to rust-preventive coating, and were processed so that there was no exposed portion of carbon steel. Thereafter, a salt spray test specified in JIS Z2371 was conducted to investigate the occurrence of red rust on the sprayed coating surface. As a comparative test piece, a 150 μm-thick thermal sprayed coating made of the thermal spraying material shown in Table 1 to which no metal Al was added was used.

Table 3 shows the results of the salt spray test. In the comparative examples (Nos. 8 to 14), red rust had already formed in a dotted shape after the salt spray test for 24 hours, and the occurrence rate of red rust after 48 hours reached 1 to 10% (surface area ratio). However, it was recognized that the carbon steel base material was poor in rust prevention. On the other hand, in the present invention example using the thermal spray coating containing metal Al, generation of red rust was not recognized even after 96 hours,
It was found that carbon steel base material had excellent rust prevention ability.

The reason for the above results is that, in the sprayed coating of the comparative example, salt water penetrates into the inside through the pores to form a local battery between the coating and the base material, and is electrochemically low. It is considered that corrosion progressed as the carbon steel base material became an anode, and the eluted ions became red rust and emerged on the film surface. On the other hand, in the thermal spray coating conforming to the present invention containing metal Al, when the thermal spray particles are heated in a heat source, the metal Al having a low melting point is quickly melted to promote the mutual bonding of the particles. This is considered to be due to the elimination of the pores and the prevention of the intrusion of the salt water. As is clear from the results in Table 3, the sprayed coating of No. 10 had red rust already generated after 24 hours despite the use of an alloy containing 6 wt% of Al in the sprayed material. I have. That is, it is completely alloyed in the sprayed metal material
It is clear that those containing Al have poor anticorrosion properties,
It is necessary that the form of metallic Al in the film is solid solution in a non-reacted state as free metallic Al.

[0029]

[Table 2]

[0030]

[Table 3]

Example 2 From the results of Example 1, it is considered that the thermal spray coating containing metal Al in the free state formed on the test piece according to the present invention has no pores. Therefore, of these coatings, those which do not contain iron (Fe) in the material components (DG) were selected, and after forming a sprayed coating in the same manner as in Example 1, the JIS
H8666 The presence or absence of through-pores in the coating was investigated by the prescribed ferroxyl test method. Table 4 shows the results of this test. In the sprayed coatings of Comparative Examples (Nos. 5 to 8), blue spots were clearly observed, whereas the sprayed coatings of the present invention (No. In (4), only small blue spots occurred in one or two places. Next, the sprayed coating having blue spots was kept in an electric furnace maintained at 700 ° C. for 15 minutes, and then subjected to a ferroxyl test again.
No new blue spots occurred.

From these results, the thermal spray material was heated in the thermal spraying heat source, and the metallic Al added to the material was added.
It is important that the bonding force between particles be completed by melting the particles. If the interparticle bonding force is insufficient, it has been found that an operation of completing the above-mentioned action by heating the film to a temperature higher than the melting point of Al (660 ° C.) after film formation is effective. In contrast, the thermal spray coatings of Comparative Examples (Nos. 6 and 8)
), No sealing effect due to heating was observed, and many blue spots were generated.

[0033]

[Table 4]

Example 3 In this example, assuming a steel structure constructed in a heavy industrial zone adjacent to the coast, the atmosphere of the salt spray test of Example 1 was acidified (pH 4.0) with sulfuric acid. A corrosion test was performed. As the thermal spray coating of the comparative example, the current JIS H8300 (199
9) High-speed flame spraying of specified materials such as Zn, Zn-10wt% Al, Al, and Al-5wt% Mg was used to test the coating.

Table 5 shows the results. Since the test atmosphere was extremely severe, the coating of the comparative example was significantly dissolved after 48 hours, and red rust was generated from the carbon steel substrate over the entire surface. On the other hand, the thermal spray coating containing free metal Al of the present invention exhibits good corrosion resistance as a whole, though spot red rust is observed in some of the coatings (Nos. 1 and 2). There was found.

[0036]

[Table 5]

Embodiment 4 In this embodiment, a sprayed material 70 of carbon steel of the same quality as carbon steel is used.
wt%, metal Al, Al-3wt% Si alloy, Al-5wt% Zn
Carbon steel test specimens (SS400 dimensions: width 50 x length 100 x thickness 5) were prepared by high-speed flame spraying using a powder-sprayed material containing 30 wt% of each of Al and Al-5 wt% Mg alloys.
mm) was formed to a thickness of 200 μm according to the present invention. In addition, part of the test piece was
Heat treatment was performed for 1 hour. At the time of heating, Ar gas was passed to prevent oxidation of the carbon steel. The salt spray test was performed on the thermal sprayed coating prepared as described above in the same manner as in Example 1.

Table 6 summarizes the results.
Each of the carbon steel and the carbon steel sprayed coating of the comparative example was 48
Although red rust was generated over the entire surface after the time, the thermal sprayed coating of the present invention generated red rust having about 1 to 4 spots, but did not show any significant development and showed excellent corrosion resistance. Further, after the film was formed, the heat treatment tended to reduce the occurrence of spot-like red rust somewhat.

[0039]

[Table 6]

[0040]

As described above, according to the present invention,
Even if the carbon steel substrate is coated with a material that shows electrochemically equivalent or noble potential, the free metal Al that plays the role of sacrificial anode on the substrate is mixed into the film. In the case where an Al intermetallic compound is generated in the coating by heating with a thermal spraying heat source or by heat treatment after film formation, it is also possible to eliminate pores by the heat generated by the heating. It has become possible to sufficiently exhibit the original corrosion resistance of the material. Therefore, according to the present invention, it is possible to provide a sea water or NO _x, spray coating member having excellent adhesion durability against corrosive gases such as SO _x. In addition, according to the present invention, the durability of Zn, Al and their alloy sprayed coatings can be overcome, the problem of which has been shortened due to environmental pollution. And at the same time, the life of the film can be greatly improved.

Claims (8)

[Claims] 1. A thermal sprayed anticorrosion coating of a corrosion-resistant metal having an electrochemically noble potential equal to or higher than that of a base metal is formed on the surface of a metal base. A spray-coated member excellent in corrosion resistance, characterized by containing 1 to 30% by weight of metal aluminum or aluminum alloy in a free state. 2. A thermal sprayed anticorrosion coating of a corrosion resistant metal having a potential no less than electrochemically equivalent to the base metal is formed on the surface of the metal substrate, and the thermal sprayed anticorrosion coating includes Containing 1 to 30% by weight of metal aluminum or aluminum alloy in a free state, and Al formed by a metallurgical reaction between aluminum and the metal material having a noble potential.
A spray-coated member excellent in corrosion resistance characterized by containing 0.3 to 15 wt% of an intermetallic compound. 3. When the metal substrate is carbon steel, the corrosion-resistant metal components having an electrochemically equivalent or noble potential with respect to carbon steel include Ni, Cr, Co, Cu, Ti, Mo and The thermal spray coated member according to claim 1, wherein the thermal spray coated member is made of at least one metal or alloy selected from Fe. 4. The thermal spray protection according to claim 2, wherein:
In the film, Fe₃Al, FeAl, FeAl₂, FeAl₃, NiAl₃,
Ni₂Al₃, NiAl, Ni₃Al, Co₂Al₉, Co₄Al ₁₂, Co₂
Al₅, CoAl, CrAl₇, Cr₂Al₁₁, Cr₄Al₉, Cr₅Al₈
And Cr₂One or more Al intermetallic compounds selected from Al
Thermal spray coating with excellent corrosion resistance characterized by being included
Element. 5. A powder material comprising metal aluminum or an alloy thereof and a corrosion-resistant metal having a noble potential that is electrochemically equal to or higher than that of the base metal contained as a balance on the surface of a metal base. A method for producing a spray-coated member having excellent corrosion resistance, comprising forming a sprayed anti-corrosion coating by spraying and leaving 1 to 30 wt% of free metal aluminum or its alloy in the coating. 6. A powder material composed of metallic aluminum or an alloy thereof and a corrosion-resistant metal having a noble potential electrochemically equal to or more than the base metal contained as a balance on the surface of a metal base material. At the same time as spraying to form a thermal sprayed anti-corrosion coating, 1 to 30 wt% of free metal aluminum or its alloy is left in the coating, and then the thermal sprayed anti-corrosion coating is heat-treated at a temperature higher than the melting point of aluminum. And a method for producing a thermal spray-coated member having excellent corrosion resistance, further comprising forming and dispersing an Al intermetallic compound in the coating. 7. When the metal substrate is carbon steel, the corrosion-resistant metal component having an electrochemically equivalent or noble potential with respect to carbon steel includes Ni, Cr, Co, Cu, Ti, Mo and The method according to claim 5, wherein the method comprises at least one metal or alloy selected from Fe. 8. The thermal spray protection according to claim 6, wherein
In the film, Fe₃Al, FeAl, FeAl₂, FeAl₃, NiAl₃,
Ni₂Al₃, NiAl, Ni₃Al, Co₂Al₉, Co₄Al ₁₂, Co₂
Al₅, CoAl, CrAl₇, Cr₂Al₁₁, Cr₄Al₉, Cr₅Al₈
And Cr₂One or more Al intermetallic compounds selected from Al
Thermal spray coating with excellent corrosion resistance characterized by being included
Manufacturing method of the member.