JP3224166B2 - Material for molten metal bath - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member for a molten metal bath, and particularly to various rolls, bearings, sleeves, bushes, and plating used in the fields of hot-dip galvanizing, hot-dip zinc-aluminum alloy plating, hot-dip aluminum plating, and the like. It is a proposal for a surface treatment technique for a molten metal bath member such as a metal fitting for adjusting the amount.

[0002]

2. Description of the Related Art Plating layers such as hot-dip galvanized coating, hot-dip aluminum coating, and hot-dip zinc-aluminum alloy plating exhibit excellent rust prevention and anticorrosion properties. It is a useful surface treatment technology that is used for main components such as products and still plays a major role even today.

[0003] In general, in many cases, a galvanized steel sheet produced in large quantities is subjected to a continuous plating treatment as shown in FIG. This continuous hot-dip galvanizing apparatus includes a sink roll 2 immersed in a plating bath 1, a support roll 3 disposed near the surface in the plating bath, and a plated steel sheet 4 after passing through these rolls. A guide roll 5 for guiding, an injection nozzle 6 for blowing off excess zinc attached to the steel plate with nitrogen gas or water vapor, and the like are provided. As described above, the molten metal bath member of the present invention is immersed in the plating bath or is installed in a location where the molten zinc is liable to be scattered and adhered,
In addition, since it is used so as to come in contact with high-temperature steel sheet to which molten zinc adheres, (1) it is difficult for erosion by molten zinc to occur, (2) it is hard to be worn even when it comes in contact with threading material (steel sheet), ) Easy removal of adhered molten zinc and easy maintenance and inspection, (4) Long life as a plating material and low cost, (5) Good resistance to thermal shock when immersed in a hot molten zinc bath Performance such as endurance is required.

[0004] In order to meet such a demand, taking a film for a sink roll as an example, (1) JP-B-56-39709,
JIS H8303 (1976) enacted in JP-B-58-11507, JP-A-59-153875, JP-A-1-108334, JP-A-64-79356 and JP-A-2-125833. (2) as disclosed in JP-A-61-117260, JP-B-3-54181 and JP-B-4-27290. , Zr
Oxide ceramic film composed of O ₂ and Al ₂ O ₃ formed by thermal spraying. (3) Japanese Patent Publication No. 58-37386,
JP 212366, JP-A-2-180755, JP-A-3-94
No. 048, JP-A-4-13857 and JP-A-4-13857
As disclosed in Japanese Patent No. 346640, a cermet thermal spray coating formed by coexisting metals such as Cr, Ni, and Co on non-oxide ceramics such as carbides, nitrides, and borides; As disclosed in Japanese Unexamined Patent Publication No. Hei 4-13857,
(5) In addition, Japanese Patent Publication No. 52-22934, in which molten metal is welded and welded, and Japanese Patent Application Laid-Open No. 53-128538, in which W is spray-coated, Cr is sprayed. For example, Japanese Patent Application Laid-Open No. 4-165058 has been proposed. With respect to the above-described technologies, the inventors have also conducted research on development of similar technologies. That is, in (6) Japanese Patent Application No. 63-49846 (Japanese Patent Application Laid-Open No. 1-222561), in a WC cermet,
28%, with a porosity of 1.8% or less and a film thickness of 0.0%
Thermal spray coating with a thickness of 40 to less than 0.10 mm, (7) Japanese Patent Application No. 63-192753
Japanese Patent Application Laid-Open No. 2-43352 discloses a method in which a boride or a material containing 5 to 28% of Co is formed by reduced pressure plasma spraying.
No.-236266), using a material in which ZrB ₂ , TiB ₂ and various carbides contain 5 to 40% of Ta and Nb, and using a low-pressure plasma spraying method, the coating surface roughness Ra is 0.01 to 5 μm.
(9) In Japanese Patent Application No. 1-124010 (Japanese Utility Model Application No. 3-63565), a cermet sprayed coating mainly composed of carbide is formed by a chemical densification method. Cr ₃ O ₃ formed film, (10) Japanese Patent Application No. 2-201
No. 187 (Japanese Unexamined Patent Publication No. 4-88159), a coating obtained by changing a part of a carbide sprayed coating to a boride by a boride treatment;
(11) In Japanese Patent Application No. 3-31448 (Japanese Patent Application Laid-Open No. 4-254571), Al or an Al-Zn alloy is diffused by heating to various carbides, borides or cermet sprayed coatings thereof.
Improved molten zinc resistance, (12) Japanese Patent Application No. 3-31448
Japanese Patent Application Laid-Open No. Hei 4-254571, Japanese Patent Application No. Hei 3-222425 (Japanese Patent Application Laid-Open No. Hei 4-358055), in which Al or Al-Zn is diffused and infiltrated into a sprayed coating of non-oxide ceramics.
A thermal spray coating formed by using a thermal spraying material obtained by adding Al or an Al-Zn alloy to a non-oxide ceramic powder or a powder obtained by mixing a metal with the non-oxide ceramic powder; In Japanese Patent Application Laid-Open No. 5-33113, a thermal spraying material obtained by adding an Al-Fe alloy or an Al-Fe-Zn alloy to a non-oxide ceramic powder or a powder obtained by mixing a metal with the non-oxide ceramic powder is used. Thermal spray coating formed (15)
-266874 (Japanese Patent Application Laid-Open No. 5-78801) has proposed various techniques and films, such as a steel roll having an Al-Fe alloy layer having an Al content of 22% or more formed on the surface thereof.

[0005]

As can be seen from the above description, the research issues concerning the thermal spray coating formed on the conventional hot-dip galvanizing bath members are to select a hot-dip galvanizing coating material, to improve the adhesion of the coating, The main characteristics were improvements in the characteristics of the film itself, such as improvement in the denseness of the film and control of the surface roughness of the film, and each had an effect of improvement. However, with the recent increase in demand for hot-dip galvanized steel sheets, demands for improving the operation rate of plating plants and improving the quality of coated steel sheets have become extremely strong. Adhesion of the floating fine dross component (Zn-Fe, Zn-Fe-Al alloy) on the sprayed coating surface, and even the generation of micro-small scratches on the steel sheet due to the dross that adheres The situation has come. Therefore, the present invention is a proposal of a technique aiming at providing a molten metal bath member provided with a molten metal sprayed coating capable of sufficiently satisfying these requirements.

[0006]

As a result of various experimental studies, the inventors have found that the penetration of molten metal into the sprayed coating can be prevented by employing a dense carbide cermet coating. For the attachment of the dross component,
The inventor has found that it can be prevented by coating the outermost layer with a nitride film that does not undergo metallurgical reaction with molten zinc, and has completed the present invention. That is, the present invention is the surface of the steel substrate, and the carbide cermet sprayed coating which is formed as a base layer, the surface of the underlying layer, organic binder punished
Formed by spraying physical and nitride particles, and a thermal spray coating consisting substantially only nitrides free of metal in a free state, it is sprayed bath member characterized by having a composite sprayed coating . And also, the present invention relates to steel
Thermal spraying of carbide cermet on the surface of an iron substrate
Is formed on the surface of the carbide underlayer.
Primary particles of 0.1μm nitride are mixed with organic binder
Thermal spraying of nitride spray powder material adjusted to secondary particles of ~ 50μm
By doing so, it is substantially free from free metals.
Spray coating with a thermal spray coating consisting only of oxide
A method for producing a member for a thermal spray bath characterized by forming
suggest.

[0007]

The composite thermal spray coating conforming to the present invention has a base layer
(Undercoat) is provided with a sprayed carbide cermet coating, and a sprayed coating of nitride that does not contain free metal is provided on the undercoat. In addition to exhibiting properties, it is possible to prevent the dross component from adhering. That is, this invention is a molten metal bath member with an internal anti-intrusion properties of molten zinc which is characteristic of the carbide or carbides cermet, a composite sprayed coating to obtain Bei I and dross component adhesion preventing property nitride comprises.

[0008] The main components of such a composite thermal spray coating are nitrides, and carbides and metals constituting cermets, such as TiN _, HfN, TaN, NbN, and TiN.
VN, ZrN, CrN, Si ₃ N ₄ , or AlN are advantageously suitable, and such carbides include TiC, NbC, WC, Cr ₃ C ₂ , B
₄ C, TaC, BiC, ZrC, HfC or VC are advantageously suitable, and as the metal component, Co and Co—Al alloy are suitable.

[0009] Each of these main components has properties as described below. Carbides and nitrides exhibit strong erosion resistance to the molten metal, that is, properties that make them difficult to wet with the molten metal and properties that prevent internal penetration of the molten metal. However, since these materials are not easily melted by themselves, they cannot form a sprayed coating having good adhesion, and therefore, they have always been used in a coexistence state (cermet state) with a metal component.

In the present invention, the lower carbide layer is formed by mixing Co and a Co-Al alloy,
A film is formed by thermal spraying in a so-called cermet state. On the other hand, the film constituting the outermost layer is formed by thermal spraying nitride containing no free metal. This means that it is extremely difficult to form the outermost nitride film because it does not contain any metal components. Therefore, a certain measure is required for thermal spraying of such a nitride which does not clearly show softening and melting phenomena. In this regard, in the present invention, fine particles (primary particles) having a particle size of 0.01 to 0.1 μm are used as the nitride to be sprayed, and are adjusted to secondary particles having a particle size of 3 to 50 μm using an organic binder (eg, vinyl acetate). However, it is preferable to use this as a thermal spray powder material.
When the thermal spray powder material thus adjusted is introduced into plasma as a thermal spray heat source, the fine particles in the outermost layer are softened and melted by heating, and oxidize and decompose. On the other hand, the fine particles present inside are softened or melted because they are shielded from the atmospheric gas, but oxidation and decomposition are suppressed as much as possible. As a result, when the thermal sprayed powder material collides with the object to be processed, particles that are oxidized or decomposed in the outermost layer portion are not scattered around to form a film, but the inner one is softened or melted. Then, the particles are firmly attached to the object to be treated, and a strong outer layer film is obtained. The present invention is characterized in that the outermost layer of the coating is spray-coated with nitride by utilizing such a phenomenon. When the secondary particle diameter adjusted with an organic binder is smaller than 3 μm, the rate of thermal decomposition in plasma is large, while when the particle diameter is larger than 50 μm, the central part does not sufficiently rise in temperature. No suitable film is formed. Here, the reason that the nitride forming the outermost layer of the composite film does not contain any free metal is as follows. In other words, if unreacted metal remains in the nitride generated by reacting the metal with active nitrogen, thermal spray deposition of the nitride becomes easy, but the resulting coating is extremely This is because it is easily eroded.

Next, the metal constituting the cermet will be described. In the present invention, Co or an Al alloy thereof is used as a metal used for the carbide cermet. This is because this Co has the property of reacting with other molten metals, for example, molten metal in a plating bath to form an alloy, and in particular, reacting with molten Al to form a high melting point Co-Al alloy (for example, , Co-70%
1648 ° C for Al alloy). Therefore, Al forms a Co-Al alloy layer relatively quickly in the initial stage of contact between the formed thermal spray coating and the molten metal. As a result, it has a characteristic that the subsequent Al penetration speed is extremely reduced. For example,
Al is added to a normal molten zinc bath in an amount of 0.1 to 0.2%. When a Co sprayed coating is immersed in the bath, the Al in the bath selectively forms a Co-Al alloy on the surface of the coating. (Al concentration is 1
As a result, the penetration rate of not only Al but also molten Zn into the film is extremely slow.

In the case of a recently used Zn-55% Al alloy bath, when a Co sprayed coating is immersed in such an alloy bath,
First, a Co—Al alloy film having a high Al content is formed. In this case, the penetration rate of each of the molten Zn and the molten Al into the sprayed coating is reduced as compared with metals such as Ni and Cr. As is clear from the above description, the thermal spray coating of a carbide containing Co exhibits a function as a barrier against the intrusion of the Al molten metal into the inside.

This treatment for containing a Co-Al alloy as a cermet film component in the lower carbide sprayed film is performed by immersing the Co-Al alloy in the molten metal containing Al.
The idea is to reproduce the enrichment phenomenon early in advance, and it has a function and an effect equal to or higher than that of the thermal spray coating of Co carbide cermet. In addition, the Al content in the Co-Al alloy as the cermet component is preferably 70% or less, and even if the Al content is more than that, Al will only elute into the Al-containing molten metal bath, and Since the function as a barrier is not particularly improved, the necessity is small.

[0014] Some commercially available carbides may contain free carbon depending on the production conditions, and some of the carbides and nitrides may be stoichiometrically excessive or insufficient (for example,
W ₆ C _{2 .54,} such as T _i N _1-X) may contain,
Further, C, Si, Mn, P,
It may contain impurities such as S, Fe, Cr, Ni and other impurities. However, the content of these components is not specified because there is no adverse effect on the object of the present invention. Keep it.

In the present invention, the optimum thickness for the composite thermal spray coating to exhibit its performance is a carbide cermet thermal spray coating: 40 μm to 300 μm, a nitride thermal spray coating: 10 μm.
m to 150 μm are suitable. If the thickness of the sprayed carbide cermet coating is less than 40 μm, the penetration of the molten metal cannot be sufficiently prevented, while if it is more than 300 μm, chipping occurs at the surface layer and local peeling occurs. This is because, when a nitride is formed thereon, the bonding strength between the two films may be reduced. In addition, the thickness of the nitride spray coating is 10μ.
If it is less than m, through-holes are easily generated in the coating, and the molten metal penetrates into the inside through the pores, so that the dross component cannot be prevented from adhering.
If the thickness is more than m, it takes a long time to form a film and consumes a large amount of expensive thermal spray material, which is not economical.

In the present invention, when forming the above-mentioned composite thermal spray coating, it is preferable to form the composite thermal spray coating in air and under reduced pressure plasma spraying or explosive spraying.

Furthermore, it is important that the composite thermal spray coating formed in this way is made dense, and in the case of a porous coating, the molten zinc penetrates into the interior through the pores. Even if a film is formed using a molten material having excellent resistance to molten zinc, its function cannot be sufficiently exerted. Therefore, at the time of thermal spray deposition,
It is preferable that the spraying is repeated a plurality of times so as to obtain a predetermined film thickness so that a film thickness of 3 to 30 μm is obtained per pass by adjusting the supply amount to the spray gun. When the film thickness per pass is thinner than described above, a denser film can be obtained, but it takes a long time to obtain a practical film thickness of, for example, 100 μm, which is not economical. On the other hand, when the film thickness per pass exceeds 30 μm, the porosity of the film becomes high, and the bonding force between the particles constituting the film becomes weak, so that there is a disadvantage that the film is easily peeled.

[0018]

【Example】

(Example 1) SUS403 steel was processed into a rod-shaped test piece having a diameter of 15 mm and a length of 150 mm, and was subjected to the following plasma spraying method.
(1) to (7) composite spray coating according to the present invention and the following
After forming the thermal spray coating for the comparative tests of (8) to (13), the coating was immersed in a hot-dip galvanizing bath to evaluate the coating.

The composite sprayed coating (undercoat / topcoat) according to the present invention (1). 40% TiC-50% WC-10% Co 80μm / TiN 80
μm (2). 20% Cr ₃ C ₂ -70% WC-8% Co-2% Al 100μm / T
iN 100 μm (3). 88% WC-12% Co 120μm / TiN 80μm (4). 80% WC-15% Co-5% Al 130μm / HfN 80
μm (5). 70% WC-28% Co-2% Al 80μm / TiN 80
μm (6). 60% WC-28% Co-12% Al 100μm / TaN10
0 μm (7). 94% WC-6% Co 100μm / HfN 100μm ・ Sprayed coating for comparative test (8). Self-fluxing alloy (JIS H8303 (1989)) MSFCo1 100 μ
m (9). Al ₂ O ₃ 100 μm on the film of (8) (10). 8% Y ₂ O ₃ .ZrO ₂ 200 μm on the film of (8) (11). 82% WC-12% Co 120μm (12). 40% TiC-50% WC-10% Co 80μm (13). 73% Cr ₃ C ₂ -20% Ni-7% Cr 120μm ・ Immersion conditions in hot-dip galvanizing bath (1) Bath composition 0.3% Al-Zn bath (2) Temperature 480 ℃ (3) Immersion time 7 days・ Evaluation items of coating (1) Adhesion of molten metal (2) Exfoliation of coating

The film was immersed in a 0.3% Al-added Zn bath, and the film was evaluated. The results are shown in Table 1. As is evident from the results, in the self-fluxing alloy film (No. 8) of the comparative example, although the peeling of the film was not observed, the zinc and the self-fluxing alloy were strongly bonded by a metallurgical reaction. Is coated with a thick zinc lump, which is not practical. Also,
Al ₂ O ₃ (No. 9), 8% Y ₂ on the self-fluxing alloy film
In any of the test pieces coated with an oxide ceramic such as O ₃ · ZrO ₂ (No. 10), the coating peeled off and the ceramic coating peeled off, and the portion where the self-fluxing alloy was directly in contact with the molten zinc was applied. Had strong zinc attached.
This is because the molten zinc penetrates into the inside through the pores of the ceramic coating of Al ₂ O ₃ or 8% Y ₂ O ₃ .ZrO ₂ , reacts with the self-fluxing alloy of the undercoat, expands its volume, and expands the volume of the ceramic coating. It is presumed that peeling was induced. Further, WC-Co (No. 11), TiC-WC
_{-Co (No.12), Cr 3 C} 2 -Ni-Cr (N
o. 13) It because only the carbide cermet thermal spray coating, such as
In shall, although peeling of the film was not Me sure, zinc and dross was deposited thinly. Probably these charcoals
Metal component and zinc contained in the product cermet thermal spray coating is considered due to a reaction. In contrast, carbide
Specimens (Nos. 1 to 7) according to the present invention in which a nitride sprayed coating was formed as a top coat on a -met sprayed coating.
When the peeling of the skin film is not observed at all, also, it was pulled zinc deposition also is locally limited (test piece from the zinc bath,
Only the zinc that had flowed to the lower portion and adhered was adhered), and the adhesion was so weak that the zinc was easily peeled off with a finger after cooling.

[0021]

[Table 1]

(Example 2) Using the test pieces on which the composite sprayed coating according to the present invention and the comparative coating used in Example 1 were formed, 5% Zn-55% Al alloy bath maintained at 610 ° C was used. After immersion for a day, it was lifted out of the bath and the state of adhesion of the molten metal and the state of peeling of the film were observed.

Table 2 summarizes these results. As can be seen from the results, the alloy for the metallurgical reaction with the coating adhered firmly over the entire surface (No. 8), or the alloy that entered the interior through the pores of the oxide ceramic coating The self-fluxing alloy of the undercoat film reacts with the undercoat film to expand the volume, thereby peeling off the ceramic film of the top coat (Nos. 9 and 10). Although not found, phenomena such as the Zn-Al alloy adhered over the entire surface were observed (Nos. 11 to 13). On the other hand, in the composite sprayed coating according to the present invention, no peeling of the coating was observed at all, and the adhesion of the Zn-Al alloy was 12% to 18% of the area of the immersion coating.
%, And the adhesion of the alloy was weak enough to be easily peeled off with a finger.

[0024]

[Table 2]

(Example 3) SUS-403 used in Example 1
After forming a composite sprayed coating according to the present invention of the following (1) to (7) on a steel test piece, it was immersed in a hot-dip aluminum plating bath and its coating performance was examined. Furthermore, in this test, using various self-fluxing alloys specified in JIS H 8303 (1889) as the undercoat, and forming a thermal spray coating of the following (8) to (14), the molten aluminum resistance was compared and studied. .

The composite thermal spray coating of the present invention (undercoat / topcoat) (1). 40% TiC-50% WC-10% Co 150μm / TiN 8
0 μm (2). 20% Cr ₃ C ₂ -70% WC-8% Co 80μm / TiN 10
0 μm (3). 88% WC-12% Co 130μm / TiN 80μm (4). 80% WC-15% Co 130 μm / HfN 80 μm (5). 70% WC-15% Co-5% Al 80μm / TiN 80
μm (6). 60% WC-28% Co-2% Al 100μm / TaN 80
μm (7). 94% WC-6% Co 110μm / HfN 80μm ・ Sprayed coating for comparison test (undercoat / topcoat) (8). Self-fluxing alloy (JIS H8303 (1989)) MSFNi1 150 μ
m / TiN 80 μm (9). Same as above Standard MSFNi2 150 μm / TiN 80 μm (10). Same as above Standard MSFNi3 150 μm / TaN 80 μm (11). Same as above Standard MSFNi4 150 μm / HfN 80 μm (12). Same as above Standard MSFNi5 150 μm / TiN 80 μm (13). Same as above MSFCo1 150 μm / TaN 80 μm (14). Same as above MSFCo2 150 μm / HfN 80 μm ・ Immersion conditions in hot-dip aluminum plating bath (1) Bath composition 10% Si-Al bath (2) Temperature 660 ° C (3) Immersion time 3 days ・ Coating evaluation items (1 ) After the start of immersion in the plating bath, the test piece was pulled up every day and the appearance of the film was observed.

Table 3 summarizes the results of observation of the appearance of the test piece film. As is clear from these results, even if a nitride film is formed on the top coat, if the undercoat film does not have resistance to molten aluminum, the film easily collapses in one day (24 hours) (No. 8 to No. 8). 12). It is considered that the cause was that the molten aluminum penetrated into the inside through the fine pores present in the nitride film, and reacted violently with the Ni-based self-fluxing alloy film to melt it. Therefore, in the molten zinc bath of Example 1, even though some pores were present in the nitride film, good molten metal resistance was exhibited. It is necessary to further reduce. On the other hand, in the film undercoated with a Co-based self-fluxing alloy (Nos. 13 to 14), some resistance to molten aluminum was observed, and it took 2.5 days (60 hours) for the film to be completely destroyed. did. On the other hand, the coatings (Nos. 1 to 7) undercoated with the carbide according to the present invention were all three days (12 days).
Even after 0 hours), it was observed that the condition was almost healthy. In addition, the amount of the molten aluminum adhering to the surface of the film was also very small as compared with the comparative example. The top coat nitride film did not show any reaction with the molten aluminum.

[0028]

[Table 3]

(Example 4) The bar-shaped test piece used in Example 1 was sprayed with 100% of 88% WC-12% Co, and then 80% TiN-20% TaN or 90% TiN-10%. A mixed nitride of HfN was formed to a thickness of 80 μm. The test piece on which the thermal spray coating was formed in this manner was immersed in a molten metal under the following conditions, and the change in the coating was examined. (1). 0.3% Al-Zn bath, 480 ° C, 7 days (immersion conditions in Example 1) (2). 45% Zn-55% Al bath, 610 ° C, 5 days (immersion conditions of Example 2) (3). 10% Si-90% Al bath, 660 ° C, 3 days (immersion conditions of Example 3)

As a result, any of the composite sprayed coatings of the present invention has very little adhesion of the molten metal, and the adhesion is so weak that the adhered molten metal can be easily peeled off with a finger. Was. As is clear from these results, it has been found that when spraying nitride as a top coat, the effect is not adversely affected even when a plurality of nitrides are used in a mixed state.

As is evident from the above examples, the sprayed carbide cermet coating is an undercoat, and
Composite sprayed coating according to this to form a thermal spray coating of a nitride which does not contain a free state metal invention, molten zinc, molten zinc - exhibit excellent resistance to molten metal of the aluminum alloy and molten aluminum dross component Has been found to prevent the adhesion of As a result, even in actual plating work, it is expected that a great effect will be exerted on quality improvement of the plated steel sheet.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a hot-dip galvanizing bath, various rolls attached thereto, and other arrangement states.

[Description of Signs] 1 molten zinc bath 2 sink roll 3 support roll 4 steel plate for plating 5 guide roll 6 spray nozzle

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 4/10

Claims (4)

(57) [Claims] 1. An underlayer formed on the surface of a steel substrate
Carbides cermet sprayed coating is, the surface of the underlying layer
Spraying nitride particles treated with organic binder
Formed by substantially free of metal in a free state comprising a thermal spray coating consisting only of nitride, spray bath member characterized by having a composite sprayed coating. 2. The free metal-free nitride comprises TiN, HfN, NbN, TaN, VN, ZrN, CrN, Si ₃ N ₄ and A
The member for a molten metal bath according to claim 1, comprising at least one member selected from the group consisting of 1N. 3. The carbide component constituting the carbide cermet sprayed coating is TiC, NbC, WC, TiC, Cr ₃ C ₂ , B ₄ C, Zr
The member for a molten metal bath according to claim 1, wherein the member is at least one selected from C, HfC and VC, and the metal component is Co or an Al alloy thereof. 4. A carbide cermet on a surface of a steel base material.
Is sprayed to form a carbide underlayer, and the carbide underlayer is
Primary particles of 0.01-0.1 μm nitride on the surface of
Nitride adjusted to 3 to 50 μm secondary particles using an inder
By spraying thermal spray powder material, free metal is removed.
By providing a thermal spray coating consisting essentially of nitride that does not contain
Spray bath characterized by forming a composite spray coating
Manufacturing method of the member for use.