JP2000345314A - High hardness carbide cermet sprayed coating-coated member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the hardness of the member and to improve its wear resistance by forming sprayed coating of a chromium carbide cermet having a specified compsn. of chromium carbide and Ni and/or carbide forming metal(s), and in which the porosity and average hardness are controlled to specified values on the surface of a heat resistant metallic base material. SOLUTION: Sprayed coating to be formed on the surface of a base material has chemical components composed of, by weight, 95 to 50% chromium carbide and 5 to 50% Ni and/or one or more kinds of carbide forming metals among Cr, Ta, Ti, W, Mo and Nb. Then, it has film characteristics in which porosity shows the value of <1.20%, and the average hardness >=1000 Hv. The sprayed coating film can be obtd. by first executing thermal spraying in which the velocity of spray particles flying in a heat source is >=200 m/sec at 1800 to 2800 deg.C heat source temp. and next subjecting the formed sprayed coating film to heat treatment at 500 to 900 deg.C for 0.3 to 3 hr in the air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member coated with a high-hardness carbide cermet sprayed coating, and more particularly to a technique for forming a chromium carbide cermet sprayed coating useful on applications requiring wear resistance on the surface of the member. . The chromium carbide cermet sprayed coating member produced by applying the technique of the present invention can be suitably used even in an environment where heat resistance and erosion resistance are required.

[0002]

2. Description of the Related Art In a thermal spraying method, a metal (alloy), ceramics, cermet, glass, plastics, or the like is melted or semi-molten into fine particles on a substrate surface by a heat source such as a combustion flame or a plasma jet. This is one of the surface treatment techniques for forming a film by attaching. The sprayed coating obtained by applying this technology is a material that cannot be fused metallurgically if it is a material that can be melted by a heat source. If it is, a film can be formed. Accordingly, the types of coatings formed by the thermal spraying method are extremely large, and the coatings can even be imparted with properties that cannot be obtained by other existing surface treatment methods. On the other hand, depending on the type of thermal spray material having too many combinations and the selection of thermal spraying conditions (type of heat source, heat source temperature and speed, thermal spray atmosphere, etc.), the properties of the thermal spray coating to be formed greatly change. However, there are still many problems to be solved in completing this technology.

[0003] Among these sprayed coatings, the carbide cermet sprayed coating is a coating that utilizes the high hardness properties of the carbide. However, in reality, the carbide itself does not melt, so it must be used as a binder. Usually, a metal component is added and used as a so-called carbide cermet.

Here, the chromium carbide to which the present invention is directed
The (Cr ₃ C ₂ ) cermet sprayed coating is WC
As high as cermet sprayed coating (WC-12wt% Co coated with H
V: 1100-1250), but because of its excellent heat resistance, abrasion resistance of heat treatment rolls for steel sheets (for example, JP-B-62-27133, JP-A-62-136421, etc.) and steel pipes for boilers Used as a coating for improvement. (For example, JP-A-2-61051, JP-A-7-305159, etc.).
However, the abrasion-resistant coatings used in these high-temperature environments have attained the intended purpose, but are still insufficient. In particular, in recent years, there has been a demand in the industry for labor saving and reduction in maintenance and management costs, as well as a demand for technologies to increase the service life of sprayed coatings, that is, to increase the hardness of chromium carbide cermet coatings obtained with current technologies. There is.

[0005] To meet such demands, conventionally,
For example, Japanese Patent Application Laid-Open No. 2-61051 discloses that "
Chromium carbide cermet thermal spray coating, which sprays a carbide-metal composite powder in which chromium carbide particles and metal particles are mixed, and heat-treats this at a temperature of 300 to 800 ° C to produce chromium oxide in the spray coating. Also, Japanese Patent Application Laid-Open No. 7-30
In Japanese Patent No. 5159, a chromium carbide / nichrome composite material is plasma-sprayed, and is subjected to 700 to 10 in a non-oxidizing atmosphere.
Techniques such as a method of performing heat treatment at 00 ° C. have been proposed.

[0006] Among the prior art, the former one is a heat treatment in an oxygen-containing atmosphere such as air, water vapor, or an oxidizing atmosphere to promote oxidation of the film constituents to hard chromium oxide (Cr ₂ O). ₃ ) This is a method of producing powder and thereby improving the wear resistance of the thermal spray coating. However, this method has the disadvantages that the oxidation of the film is severely oxidized, and oxygen reaches the substrate surface through the pores of the film, thereby causing the film to peel off. In addition, this film contains a large amount of Cr in the pores.
_{When 2} O ₃ is generated, a volume change occurs, and minute cracks are generated in the film itself, causing local peeling, so that the wear resistance cannot be exhibited for a long time. On the other hand, the latter conventional technique is a technique of performing a heat treatment in a non-oxidizing atmosphere, but the hardness of the film formed by this method is not so high.

[0007] Therefore, the inventors have once related to this technology,
A technique disclosed in Japanese Patent Application Laid-Open Nos. 8-74024 and 8-74025 has been proposed. This technology heat-treats the sprayed coating in a chromium halide vapor containing hydrogen gas to increase the hardness and increase the hardness by forming Cr ₂₃ C ₆ carbide on the surface of the coating and filling the coating pores with fine chromium particles. It is intended to improve corrosion resistance. However, these techniques require a special heat treatment vessel, which makes it difficult to apply them to large members, and further improvement has been desired.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the following problems of the above-described prior arts. (1) Detrimental effects caused by chromium oxide (Cr ₂ O ₃ ) generated when chromium carbide cermet sprayed coating is heat-treated in air, water vapor, or oxidizing atmosphere, that is, depletion and peeling of coating, and fine cracks To prevent shortening of the service life due to the occurrence of cracks. (2) To overcome the adverse effects seen when heat-treating a chromium carbide cermet sprayed coating in a non-oxidizing atmosphere, that is, the problem that its use is limited because the hardness does not increase sufficiently.

Accordingly, a main object of the present invention is to propose a technique for forming a high hardness carbide cermet sprayed coating having high hardness and excellent wear resistance on the surface of a base material. Another object of the present invention is to propose a technique for forming a chromium-based high-hardness carbide cermet sprayed coating exhibiting excellent properties such as heat resistance and erosion resistance on a substrate surface.

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems in the prior art, as a result of intensive studies, the following findings were obtained. (1) When depositing a chromium carbide cermet sprayed material by high-speed flame spraying, a sprayed coating with low porosity should be formed if the residence time in the heat source is minimized to suppress oxidation and decomposition of the carbide. Can be. (2) The above thermal spray coating is formed at 500-900 ° C in air at 0.
When the heat treatment is performed for 3 to 3 hours, the film is hardened, and the entry of high-temperature air into the film is prevented due to the small pores, so that oxidation inside the film can be prevented. (3) If air is prevented from entering the film,
Carbon easily moves between the Cr ₃ C ₂ particles and the metal binder, carburization of the binder metal occurs, and the coating becomes harder. (4) For the above chromium carbide cermet spray coating,
When a heat-resistant metal (alloy) thermal spray coating is formed as a top coat on it to form a multilayer structure and then heat-treated, the chromium carbide cermet thermal spray coating, which is the undercoat, is exposed to higher temperatures without being oxidized. Heat treatment (500 ~
(1150 ° C.), the carburizing reaction and the sintering reaction of the entire sprayed coating can be promoted, and the heat treatment time for increasing the hardness can be shortened. (5) Chromium carbide cermet is formed by heat-treating a multi-layer structure film formed by spraying a heat-resistant alloy as a top coat on the chromium carbide cermet sprayed film while using the temperature of the operating environment while preventing the oxidative consumption of the undercoat. Higher hardness of the thermal spray coating can be reliably achieved.

Under such a concept, the present invention achieves the above object by adopting the following gist configuration. (1) On the surface of the heat-resistant metal substrate, the chemical component is 95 to 50% by weight of chromium carbide and Ni and / or “Cr, Ta, Ti, W,
A film comprising at least one carbide-forming metal selected from Mo and Nb ": 5 to 50 wt%, and having a porosity of less than 1.20% and an average hardness of Hv: 1000 or more A high hardness carbide cermet sprayed coating member comprising a chromium carbide cermet sprayed coating having characteristics. (2) On the surface of the heat-resistant metal substrate, the chemical composition of the coating is 95 to 50 wt% of chromium carbide and Ni and / or “Cr, Ta, T”.
i, W, Mo and Nb, any one or more of carbide-forming metals ": 5 to 50 wt% and a porosity of
Undercoat of chromium carbide sprayed coating with less than 1.20% and Co, Ni, Cr, Al,
A composite thermal spray coating consisting of a top coat of two or more heat-resistant alloy thermal spray coatings selected from Y, Ta and Si is formed,
And the average hardness of the undercoat of the composite spray coating is H
v: A member coated with a high-hardness carbide cermet sprayed coating having a coating characteristic of 1000 or more.

The above-mentioned member is manufactured by applying the following method. (3) A chromium carbide cermet material containing Ni and / or a carbide forming metal is sprayed on the surface of the base material at a thermal spray heat source temperature of 18
00-2800 ° C, spray particle velocity in thermal spray heat source: 2 per second
The porosity is 1.20% by spraying under the condition of 00m or more.
Less than 500 thermal spray coatings, and then
A high-hardness carbide cermet spray-coated film characterized by obtaining a chromium carbide cermet spray-coated film hardened to a hardness having an average hardness Hv of 1000 or more by heat treatment at ~ 900 ° C for 0.3 to 3 hours. Manufacturing method. (4) A chromium carbide cermet material containing Ni and / or a carbide forming metal is sprayed on the surface of the base material at a thermal spraying heat source temperature of 18
00-2800 ° C, sprayed particle velocity in thermal spray heat source: 20 per second
The porosity is 1.20% by spraying under the condition of 0 m or more.
An undercoat consisting of less than chromium carbide cermet sprayed coating is formed, and then a heat-resistant alloy is sprayed on the sprayed coating to form a topcoat consisting of a heat-resistant alloy sprayed coating to form a composite sprayed coating. By heat-treating the sprayed coating in an air atmosphere at 500 to 1150 ° C. for 0.3 to 1.5 hours, the undercoat sprayed coating is hardened to a hardness showing an average hardness Hv of 1000 or more. A method for producing a member coated with a hardened carbide cermet sprayed coating.

According to the present invention, in the method described in the above (4), the composite sprayed coating is maintained at a temperature of 500 to 1150 ° C. by placing the member in an operating environment instead of a method of heat-treating the composite sprayed coating in an air atmosphere. In this case, the average hardness of the chromium carbide cermet sprayed coating of the undercoat may be set to Hv: 1000 or more.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Thermal Spray Material The chromium carbide particles used as the thermal spray material are Cr ₃ C ₂ , Cr
Any compound can be used as long as it is at least one carbide selected from ₇ C ₃ and Cr ₂₃ C ₆ . If the content of this chromium carbide is less than 5 wt%, T
Metal carbides such as aC, NbC, TiC, WC, and B ₄ C may be included. On the other hand, as a metal binder component to be added to the chromium carbide, on the assumption that Ni is used, further, a carbide forming metal having a strong chemical affinity with carbon, such as Ta, Ti, W, Mo, Nb, Cr, etc. Metals (alloys) containing any one or more of these are preferred. The content of the metal binder component is preferably in the range of 5 to 50% by weight (the remainder is chromium carbide). If the content of the metal binder is less than 5% by weight, the bonding force between the particles is weak, and there is a possibility that the particles are peeled off by a thermal shock. Can not be expected to increase hardness. Here, the reason that the addition of Ni is indispensable as a metal binder is that Ni itself does not generate a hard carbide, so while always maintaining high toughness, it is easy to alloy and mix with other metal components, The reason therefor is to have binder properties having good physical bonding with the carbide particles and to improve excessive brittleness of the high hardness carbide film.

(2) Thermal Spraying Method In the present invention, the thermal spray coating formed on the member surface is formed by spraying particles sprayed in the heat source at a heat source temperature of 1800 to 2800 ° C. in order to suppress oxidation and decomposition of chromium carbide of the thermal spray material. It is formed by using a thermal spraying method and a thermal spraying heat source that can obtain a condition of 200 m or more at a speed of second. For example, high-speed flame spraying and explosive spraying are suitable as the thermal spraying method, and the conditions of low heat source flow rate are also unsuitable for the high-speed flame spraying. It occurs violently, and the hardness of the carbide cannot be used effectively. For example, a thermal spray coating formed by using such a thermal spraying method and using the thermal spray material described above is 1.20%.
And a porosity of less than 10%. Therefore, even if this film is heat-treated in the air, the substrate is not oxidized through the pores, and the surface of the film is also very rarely oxidized. Does not.

The thermal sprayed coating formed under the method of the present invention preferably has a thickness in the range of 80 to 800 μm, and a coating thinner than 80 μm has many pores. can not see.

(3) Thermal Sprayed Film and Heat Treatment Thereof In the present invention, the thermal sprayed film formed on the surface of the substrate, particularly the substrate made of a heat-resistant alloy, has the chemical components as described above. It is necessary that the porosity is less than 1.20% and the average hardness Hv is 1000 or more. Here, if the porosity is 1.20% or more, air (oxygen) enters the inside of the film during the heat treatment and oxidizes the base material,
This is because the bonding strength with the coating is reduced and the coating is easily peeled off, and the coating itself is oxidized from the inside, and the bonding force of the spray particles constituting the coating is weakened. In addition, it is recognized from experience in use in various plants and apparatuses during operation that the average hardness Hv of less than 1000 does not sufficiently meet the requirements for wear resistance.

[0018] The above-mentioned film characteristics are as follows.
It is obtained by heat treatment at a temperature of 00 to 900 ° C. for 0.3 to 3 hours. That is, by heat-treating the thermal spray coating, inside the thermal spray coating, chromium carbide particles and elements having strong chemical affinity with carbon such as Cr, Ta, Ti, W, Mo, and Nb in the metal binder component are formed. React with each other to form new hard carbides (Cr ₂₃ C ₂ , Cr ₇ C ₃ , TaC, TiC, W
C, WC, MoC, NbC). As a result, the hardness of the thermal spray coating further increases, and furthermore, the thermal spray coating causes a sintering reaction as a whole by this heat treatment, so that the porosity of the coating decreases and the hardness of the coating further increases. To It is needless to say that the same effects as those of the present invention can be obtained by performing heat treatment in a vacuum or in a non-oxidizing atmosphere other than in the air.

(4) Formation of a composite thermal spray coating of an undercoat and a top coat As described above, the thermal spray coating formed by the coating is formed by a carburizing reaction and a sintering reaction of the chromium carbide particles and the metal binder component by heat treatment. Hardness can be increased. In this case, there is an advantage that the effect of curing can be recognized in a short time when the heat treatment temperature (500 to 900 ° C.) is slightly increased. However, at a high temperature of 900 ° C. or higher, the rate of oxidative consumption of Cr ₃ C ₂ is high, and the risk of Cr ₂ O ₃ falling off the surface increases. Therefore, in the present invention, on the chromium carbide cermet sprayed coating (undercoat), heat resistant,
After directly applying an oxidation-resistant alloy film as a top coat to a thickness of 50 to 300 μm, heat treatment was performed in the atmosphere.
By forming such a top coat, the film is heated to 900 ° C.
Even when heated as described above, the chromium carbide cermet sprayed coating of the undercoat does not oxidize, and the curing reaction can be performed more quickly.

As the heat-resistant and oxidation-resistant alloy for the top coat, an alloy containing two or more metal elements selected from Co, Ni, Cr, Al, Y, Ta and Si is suitable.
Heat treatment when top coat is applied is 500 ~ 1150
℃, 0.3 to 1.5 hours is suitable.

In another embodiment of the present invention, a member having a composite thermal spray coating on the surface of a substrate as described above is subjected to under-heating by using the temperature of a practical environment (500 to 1150 ° C.). It is possible to guide the curing reaction of the chromium carbide cermet film of the coat. That is, the top coat exposed in a high-temperature environment is excellent in heat resistance and oxidation resistance but poor in erosion resistance, so that its life is not necessarily good. However, during the period when the top coat is consumed by erosion, the chromium carbide cermet film of the undercoat is hardened by the carburizing reaction and the sintering reaction. Already hardens at ambient temperature and exhibits excellent erosion resistance.

[0022]

Example 1 In this example, Cr ₃ C ₂ (75 wt%)-Ni (20 wt%)-Cr
(5 wt%) thermal spraying material, a 300 µm thick sprayed test piece applied to the surface of SUS410 substrate (100 mm long × 50 mm wide × 5 mm thick) by high-speed flame spraying and atmospheric plasma spraying. Produced. At the time of thermal spraying, the flying speed of the thermal sprayed particles during thermal spraying was measured using a laser speedometer, and the porosity of each test coating was measured. Thereafter, the thermal sprayed test piece was subjected to a heat treatment at 700 ° C. × 0.5 h (in air), and the increase in hardness of the coating was measured.

Table 1 summarizes these results. Film formed by plasma spraying method (No. 4)
Is porous and has a slight increase in hardness even after heat treatment. On the other hand, the coating (No.2, 3) obtained by controlling the flying speed of the sprayed particles to 200 m / sec or more using the high-speed flame spraying method has a low porosity (0.1 to 1.1%),
Moreover, it has a relatively high hardness even when sprayed. When these films are heat treated, the hardness increases further,
Hv reached 1110 (No. 3). Even in the high-speed flame spraying method, when the flying speed of the sprayed particles is less than 200 m / sec, the porosity is high, the coating hardness is not sufficient, and it is judged that it is unsuitable as a member of the present invention.

[0024]

[Table 1]

Example 2 In this example, the change in the film hardness and the durability of the film due to thermal shock when the heat treatment conditions were raised to 1050 ° C. × 0.5 h using the test piece of Example 1 were investigated. did. In addition, as a coating of the present invention, 120 μm was formed on a Cr ₃ C ₂ cermet sprayed coating (undercoat) by high-speed flame spraying.
m thick heat-resistant alloy spray coating (32wt% Ni-21wt% Cr-7wt%
Al-0.5 wt% Y-remaining Co) was formed as a top coat.

Table 2 summarizes the results.
As is clear from the results shown in this table,
No coating (No.1, 2, 5)
Regardless of the spray method, plasma spray method, etc.
Oxidized and cracked when subjected to thermal shock
And peeled off locally. In contrast, the top of heat-resistant alloys
The coated film (No.3, 4) can prevent oxidation,
Carburizing and sintering reactions of metal binder components by heat treatment
As a result, the hardness of the film is sufficiently increased. In other words, high
Even with coatings obtained by the rapid flame spraying method, the heat treatment temperature is high.
That a top coat is required
You. The Cr formed by the plasma spray method_ThreeC_TwoSa
-Met spray coating is Cr_ThreeC _TwoParticles in hot plasma
Since many of them are decomposed, the top
Heat treatment, the hardness increase due to heat treatment is slight.
Was.

[0027]

[Table 2]

Example 3 In this example, a high-speed flame spraying method and an atmospheric plasma spraying method were used on a surface of a SUS410 base material using a cermet sprayed material obtained by mixing various alloy powders with Cr ₃ C ₂ powder. Was applied to form a sprayed coating having a thickness of 300 μm. Thereafter, the thermal sprayed coating test piece was heat-treated in the atmosphere under the conditions of 830 ° C. × 2 hours, and the film hardness before and after the heat treatment was measured.

Table 3 summarizes these results.
You. As is clear from the results shown in this table, Cr_ThreeC_TwoCharring
Metal such as Ti, Ta, Nb, W together with Ni-Cr
However, high-density thermal spray coating is used to form a dense thermal spray coating.
If formed, Vickers by heat treatment in air
It is understood that a high hardness film with a hardness of 1000 can be obtained
Was. However, the film formed by the atmospheric plasma spray method
Is Cr_ThreeC _TwoIs decomposed and softened
Even if this is heat-treated, it is formed by high-speed flame spraying
Hardness as high as that of the film to be obtained was not obtained.

[0030]

[Table 3]

Example 4 In this example, after the STBA 24 steel pipe was vertically divided, the following thermal spray coating was formed on the outer surface of the steel pipe. 6
For a month, it was installed on the surface of a heat transfer tube and investigated for erosion damage caused by coal ash (fly ash). The conditions in the boiler combustion furnace are a temperature of 680 to 740 ° C. and a flow rate of combustion gas containing fly ash of 12 to 15 m / sec.

Test Sprayed Coating (Coating of the Present Invention) (1) After forming 75 wt% Cr ₃ C ₂ -20 wt% Ni-5 wt% Cr to a thickness of 300 μm by a high-speed flame spraying method, 820 in the atmosphere.
Heat treatment at 1 ° C. × 1 h. (2) 17wt% Cr-6wt% Al-0.
A heat-resistant alloy of 7 wt% Y-remaining Ni was applied to a thickness of 150 μm by a high-speed flame spraying method, and was not heat-treated. As comparative examples, (3) STBA 24 untreated (4) The undercoat of (1) was applied by air plasma spraying to 300 times.
Work to a thickness of μm. (5) Heat-treat the film of (4) in air at 830 ℃ for 1h.

Table 4 shows the appearance of the sprayed coating tube exposed in the boiler combustion furnace for 6 months and the results of measuring the wear depth of the coating. The surface of the untreated STBA 24 steel pipe (No. 5) was significantly worn by fly ash erosion, and the appearance of the wear was clearly observed. Further, even in the case of the Cr ₃ C ₂ cermet coating (No. 3) applied by the plasma spraying method of the comparative example, abrasion approximately 10 times that of the coating of the present invention is observed unless heat treatment is performed. However, when heat treatment is applied to the plasma sprayed coating (No. 4), the abrasion resistance is somewhat improved, but the coating is often cracked and the durability is poor. In contrast,
All of the films (Nos. 1 and 2) conforming to the present invention maintained a healthy state, and the wear amount was within the range of 1 to 5 μm, and exhibited excellent wear resistance. In the film (No. 2) in which the heat-resistant alloy was formed as the top coat, only the soft top coat was locally peeled off, but the undercoat maintained a healthy state and the wear amount showed the minimum value. It is considered that this is because the coating was heat-treated and hardened by the temperature conditions in the boiler combustion furnace without heat-treating the undercoat. That is, it is estimated that the curing phenomenon is promoted during the period in which the undercoat is prevented from being consumed by the presence of the topcoat, and the abrasion resistance of the undercoat is improved.

[0034]

[Table 4]

[0035]

As described above, using a cermet spray material containing one or more metals having a strong chemical affinity with carbon together with Ni, a spray heat source temperature of 1800 to 2800 ° C. and a flying speed of spray particles in the heat source Sprayed film formed at a speed of 200 m / sec or more has a porosity of less than 1.20%,
Even when heat treatment is performed at 00 to 900 ° C. for 0.3 to 3 hours, the oxidation consumption rate is low, and high curing of the film can be achieved. Furthermore, the composite thermal spray coating formed by forming a heat-resistant alloy top coat on the chromium carbide cermet thermal spray coating can perform a hardening treatment even at a high temperature of 1150 ° C. while preventing the undercoat from being oxidized and consumed. Therefore, a high hardness chromium carbide cermet sprayed coating having excellent wear resistance can be formed by using heat in the air or in a practical environment.
It is possible to expand the use of the chromium carbide cermet sprayed coating and extend the service life of the coated member, and to save plant manpower,
It can be expected to contribute to reducing maintenance costs and improving productivity.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K031 AB03 AB08 AB09 CB21 CB22 CB23 CB24 CB31 CB32 CB33 CB34 CB37 CB45 EA12 FA01 FA10

Claims (5)

[Claims] 1. A chemical composition of a coating on a surface of a heat-resistant metal substrate, wherein the chemical composition of the coating is 95 to 50% by weight of chromium carbide and any one selected from Ni and / or “Cr, Ta, Ti, W, Mo and Nb”.
Or more kinds of carbide-forming metals ": 5 to 50% by weight, having a porosity of less than 1.20% and an average hardness Hv of 1000
A high hardness carbide cermet sprayed coating member comprising a chromium carbide cermet sprayed coating having the above coating properties. 2. A chemical component on a surface of a heat-resistant metal substrate,
Chromium carbide: 95-50 wt% with Ni and / or "Cr, T"
a, at least one carbide forming metal selected from Ti, W, Mo and Nb ": 5 to 50% by weight and having a porosity of less than 1.20%. Coat and formed on it
A composite thermal spray coating consisting of a top coat of two or more heat-resistant alloy thermal spray coatings selected from Co, Ni, Cr, Al, Y, Ta and Si is formed, and the average hardness Hv of the undercoat of the composite thermal spray coating is formed. A high-hardness carbide cermet spray-coated coating member having a coating characteristic of not less than 1000. 3. A chromium carbide cermet material containing Ni and / or a carbide-forming metal on a surface of a base material under a condition of a spraying heat source temperature of 1800 to 2800 ° C. and a spraying particle velocity in a spraying heat source of 200 m / s or more. By spraying, a sprayed coating having a porosity of less than 1.20% is formed, and then heat-treated in an air atmosphere at 500 to 900 ° C. for 0.3 to 3 hours to increase the average hardness Hv to 1000 or more. A method for producing a member coated with a high hardness carbide cermet spray coating, characterized by obtaining a chromium carbide cermet spray coating having a hardness set to the indicated hardness. 4. A chromium carbide cermet material containing Ni and / or a carbide-forming metal is sprayed on a surface of a base material at a spraying heat source temperature of 1800 to 2800 ° C. and a spraying particle velocity in the spraying heat source: 200 m / sec or more. By forming an undercoat consisting of a chromium carbide cermet sprayed coating having a porosity of less than 1.20%, and then spraying a heat-resistant alloy on the sprayed coating to form a topcoat consisting of a heat-resistant alloy sprayed coating. By heat treating the composite sprayed coating in air at a temperature of 500 to 1150 ° C. for 0.3 to 1.5 hours, the hardness of the undercoated thermal sprayed coating is 1000 or more. A method for producing a member coated with a high-hardness carbide cermet sprayed coating, wherein the member is cured. 5. The method according to claim 4, wherein the member is placed in a use environment and maintained at a temperature of 500 to 1150 ° C. instead of the method of heat treating the composite sprayed coating in an air atmosphere. A method for producing a member coated with a high-hardness carbide cermet thermal spray coating, wherein the average hardness of the chromium carbide thermal spray coating in the coating is set to an average hardness of 1000 or more.