JP2006336091A - Powder for thermal spray, thermally sprayed coating, and layered body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder for thermal spray, which is suitable for forming a thermally sprayed coating being hardly exfoliated from a base material having a relatively high coefficient of thermal expansion such as a base material made of stainless steel and having excellent erosion resistance. <P>SOLUTION: The powder for thermal spray comprises cermet particles including boron, molybdenum, chromium and cobalt. In the cermet particles, the content ratio of molybdenum to cobalt is preferably within a range of 2.4-4.0, the content of chromium is preferably within a range of 11-16 mass%, and the content of cobalt is preferably within a range of 13-23 mass%. The coefficient of thermal expansion of the thermally sprayed coating formed from such a powder for thermal spray is preferably not lower than 9.5×10<SP>-6</SP>/K within a temperature range of 100-600°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt, a thermal spray coating formed from such thermal spraying powder, and a laminate comprising such a thermal spray coating on a substrate.

  For example, the thermal spray coating provided on the die cast mold for aluminum, and the thermal spray coating provided on the sink roll and the support roll used in the hot dip galvanizing bath and the hot dip zinc-aluminum plating bath have high resistance to melting, that is, Molten metal erosion resistance, heat resistance, thermal shock resistance, oxidation resistance, and wear resistance are required. As a thermal spraying powder suitable for forming such a thermal spray coating, for example, a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt as disclosed in Patent Documents 1 and 2 is known. ing.

  However, the thermal spray coating formed from the thermal spraying powders of Patent Documents 1 and 2 has a relatively small thermal expansion coefficient. Therefore, when such a thermal spray coating is provided on a substrate having a relatively large thermal expansion coefficient, such as a stainless steel substrate, the thermal spray coating peels off from the substrate when heating and cooling are repeated. There was a problem that it was easy.

In order to increase the thermal expansion coefficient of the thermal spray coating formed from the thermal spraying powder containing the cermet particles, the proportion of the ceramic component may be decreased by increasing the proportion of the metal component in the thermal spraying powder. However, a thermal spray coating formed from a thermal spraying powder with a high proportion of metal components and a small proportion of ceramic components is usually not high in resistance to erosion, and is not suitable for use in applications requiring high erosion resistance. It was.
Japanese Patent Laid-Open No. 2004-300555 JP-A-9-227243

  An object of the present invention is to provide a thermal spraying powder suitable for forming a thermal spray coating that is difficult to peel from a base material having a relatively large thermal expansion coefficient, such as a base material made of stainless steel, and also has excellent resistance to corrosion damage. It is another object of the present invention to provide a thermal spray coating that is difficult to peel from a base material having a relatively large thermal expansion coefficient, such as a base material made of stainless steel, and is excellent in resistance to erosion. Another object of the present invention is to provide a laminate in which a thermal spray coating formed by thermal spraying a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt is difficult to peel off from a substrate. .

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have been able to form a thermal spray coating capable of forming a thermal spray coating having a large thermal expansion coefficient even when the proportion of the ceramic component is large and the proportion of the metal component is small. As a result, the present invention has been completed.

  That is, the invention described in claim 1 contains cermet particles containing boron, molybdenum, chromium and cobalt, and the ratio of the molybdenum content to the cobalt content in the cermet particles is in the range of 2.4 to 4.0. A thermal spray powder is provided.

  The invention according to claim 2 provides the powder for thermal spraying according to claim 1, wherein the chromium content in the cermet particles is in the range of 11 to 16% by mass and the cobalt content is in the range of 13 to 23% by mass. To do.

  Invention of Claim 3 contains the cermet particle | grains containing boron, molybdenum, chromium, and cobalt, the chromium content in a cermet particle | grain is the range of 11-16 mass%, and cobalt content is 13-23 mass%. The powder for thermal spraying which is the range of is provided.

The invention according to claim 4 is formed by spraying the thermal spraying powder according to any one of claims 1 to 3, and has a thermal expansion coefficient of 9.5 × 10 ⁻ in a temperature range of 100 to 600 ° C. A sprayed coating that is ⁶ / K or more is provided.

The invention according to claim 5 is formed by spraying a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt, and has a thermal expansion coefficient of 9.5 × 10 in a temperature range of 100 to 600 ° C. Provided is a thermal spray coating of ⁻⁶ / K or more.

  Invention of Claim 6 provides a laminated body provided with a base material and the sprayed coating provided on the base material. However, the thermal spray coating is formed by thermal spraying a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt, and is 100 to the thermal expansion coefficient of the thermal spray coating in the temperature range of 100 to 600 ° C. The ratio of the thermal expansion coefficient of the substrate in the temperature range of ˜600 ° C. is in the range of 0.5 to 1.9.

  According to the present invention, there is provided a thermal spraying powder suitable for forming a thermal spray coating that is difficult to peel from a base material having a relatively large thermal expansion coefficient, such as a base material made of stainless steel, and also has excellent resistance to corrosion damage. In addition, it is possible to provide a sprayed coating that is not easily peeled off from a base material having a relatively large thermal expansion coefficient, such as stainless steel, and that is excellent in resistance to melting. Furthermore, according to the present invention, there is provided a laminate in which a sprayed coating formed by spraying a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt is difficult to peel off from a substrate.

Hereinafter, an embodiment of the present invention will be described.
The thermal spraying powder of this embodiment is manufactured by granulating and sintering a raw material powder containing boron, molybdenum, chromium, and cobalt. For example, the raw material powder is prepared by mixing molybdenum boride powder, cobalt alloy powder and chromium boride powder. A slurry is prepared by mixing the raw material powder in an appropriate dispersion medium, and then a granulated powder is produced from the slurry by spray granulation. The granulated powder thus obtained is sintered, further pulverized and classified, whereby the thermal spraying powder of this embodiment substantially comprising cermet particles containing boron, molybdenum, chromium and cobalt is produced.

  When the chromium content in the cermet particles exceeds 16% by mass, more specifically, when it exceeds 15% by mass, the thermal expansion coefficient of the thermal spray coating formed from the thermal spraying powder tends to be small, and the thermal resistance of the thermal spray coating is low. Loss tends to be low. Therefore, in order to obtain a thermal spray coating having a large thermal expansion coefficient and high resistance to erosion, the chromium content in the cermet particles is preferably 16% by mass or less, more preferably 15% by mass or less.

  On the other hand, when the chromium content in the cermet particles is less than 11% by mass, more specifically, less than 13% by mass, the thermal expansion coefficient of the thermal spray coating formed from the thermal spraying powder tends to be small. Therefore, in order to obtain a thermal spray coating having a large thermal expansion coefficient, the chromium content in the cermet particles is preferably 11% by mass or more, and more preferably 13% by mass or more.

  When the cobalt content in the cermet particles exceeds 23% by mass, more specifically, exceeds 21% by mass, the thermal expansion coefficient of the thermal spray coating formed from the thermal spraying powder tends to be small, and the thermal resistance of the thermal spray coating Loss tends to be low. Therefore, in order to obtain a thermal spray coating having a large coefficient of thermal expansion and high resistance to melting, the cobalt content in the cermet particles is preferably 23% by mass or less, more preferably 21% by mass or less.

  On the other hand, when the cobalt content in the cermet particles is less than 13% by mass, and more specifically less than 16% by mass, the thermal expansion coefficient of the thermal spray coating formed from the thermal spraying powder tends to be small. Therefore, in order to obtain a thermal spray coating having a large thermal expansion coefficient, the cobalt content in the cermet particles is preferably 13% by mass or more, and more preferably 16% by mass or more.

  When the total of boron content, molybdenum content, chromium content and cobalt content in the cermet particles is less than 90% by mass, more specifically less than 93% by mass, more specifically less than 95% by mass The melt resistance of the thermal spray coating formed from the thermal spraying powder tends to be slightly lowered. Therefore, in order to obtain a spray coating having higher resistance to melting damage, the total of the boron content, the molybdenum content, the chromium content, and the cobalt content in the cermet particles is preferably 90% by mass or more, and more preferably. Is 93% by mass or more, and most preferably 95% by mass or more.

  If the ratio of the molybdenum content to the cobalt content in the cermet particles is less than 2.4, more specifically less than 2.5, more specifically less than 2.7, The melt resistance of the sprayed coating formed tends to be low. Therefore, in order to obtain a spray coating with high resistance to melting, the ratio of the molybdenum content to the cobalt content in the cermet particles is preferably 2.4 or more, more preferably 2.5 or more, most preferably 2.7 or more.

  On the other hand, if the ratio of the molybdenum content to the cobalt content in the cermet particles is greater than 4.0, more specifically greater than 3.6, more specifically greater than 3.5, The thermal expansion coefficient of the thermal spray coating formed from the powder tends to be small. Therefore, in order to obtain a thermal spray coating having a large thermal expansion coefficient, the ratio of the molybdenum content to the cobalt content in the cermet particles is preferably 4.0 or more, more preferably 3.6 or more, most preferably It is 3.5 or more.

  When the crushing strength of the cermet particles is less than 100 MPa, more specifically less than 150 MPa, and more specifically less than 180 MPa, a phenomenon called spitting tends to occur during spraying. Spitting refers to a phenomenon in which deposits of sprayed powder for thermal spraying fall off from the nozzle inner wall of the thermal sprayer and are discharged toward the spray target. Spitting is likely to occur when the crushing strength of the cermet particles is in the above range. As the crushing strength of the cermet particles decreases, fine particles that may cause overmelting during spraying are generated by the collapse of the cermet particles. This is because it becomes easier. If spitting occurs during thermal spraying, the quality of the resulting thermal spray coating decreases, including the resistance to melt damage. Therefore, in order to obtain a sprayed coating having higher resistance to melting damage, the crushing strength of the cermet particles is preferably 100 MPa or more, more preferably 150 MPa or more, and most preferably 180 MPa or more.

  On the other hand, if the crushing strength of the cermet particles is greater than 600 MPa, more specifically greater than 550 MPa, and more specifically greater than 500 MPa, the spraying powder is less likely to melt during thermal spraying. (Spraying yield) may be reduced. Therefore, in order to improve the adhesion efficiency, the crushing strength of the cermet particles is preferably 600 MPa or less, more preferably 550 MPa or less, and most preferably 500 MPa or less.

  The thermal spraying powder of the present embodiment is used in applications in which a thermal spray coating is formed by a thermal spraying method such as high-speed flame spraying, plasma spraying, or explosive spraying. In order to obtain a denser sprayed coating, high-speed flame spraying is preferable. By spraying the thermal spraying powder of the present embodiment toward the base material, a laminate including the base material and the thermal spray coating provided on the base material is formed.

  In the laminate, when the ratio of the thermal expansion coefficient of the base material in the temperature range of 100 to 600 ° C. to the thermal expansion coefficient of the thermal spray coating in the temperature range of 100 to 600 ° C. is smaller than 0.5, further speaking 0.55 If it is smaller than that, more specifically if it is smaller than 0.6, there is a possibility that the sprayed coating easily peels off from the substrate when heating and cooling are repeated. This is because the thermal expansion coefficient of the substrate is too small compared to the thermal expansion coefficient of the thermal spray coating. Therefore, in order to suppress peeling of the thermal spray coating due to the thermal expansion coefficient of the substrate being too small compared to the thermal expansion coefficient of the thermal spray coating, the ratio of the thermal expansion coefficient of the substrate to the thermal expansion coefficient of the thermal spray coating is 0. .5 or more, more preferably 0.55 or more, and most preferably 0.6 or more.

  On the other hand, when the ratio of the thermal expansion coefficient of the base material in the temperature range of 100 to 600 ° C. to the thermal expansion coefficient of the thermal spray coating in the temperature range of 100 to 600 ° C. is larger than 1.9, more specifically, 1.8. If it is larger, more specifically, if it is larger than 1.75, there is a possibility that the sprayed coating easily peels off from the substrate when heating and cooling are repeated. This is because the thermal expansion coefficient of the thermal spray coating is too small compared to the thermal expansion coefficient of the substrate. Therefore, in order to suppress peeling of the thermal spray coating due to the thermal expansion coefficient of the thermal spray coating being too small compared to the thermal expansion coefficient of the base material, the ratio of the thermal expansion coefficient of the base material to the thermal expansion coefficient of the thermal spray coating is 1. Is preferably 1.9 or less, more preferably 1.8 or less, and most preferably 1.75 or less.

In order to prevent the thermal spray coating provided on a base material having a relatively large thermal expansion coefficient such as a stainless steel base material from being peeled off from the base material, the thermal spray coating in a temperature range of 100 to 600 ° C. The thermal expansion coefficient is preferably 9.5 × 10 ⁻⁶ / K or more, more preferably 10.0 × 10 ⁻⁶ / K or more, and most preferably 10.5 × 10 ⁻⁶ / K or more. is there. If it is smaller than 9.5 × 10 ⁻⁶ / K, it is easily peeled off from the base material when heating and cooling are repeated, similar to the thermal spray coating formed from the thermal spraying powders of Patent Documents 1 and 2. There is a fear. The thermal expansion coefficient in the temperature range of 100 to 600 ° C. of the thermal spray coating formed by spraying the thermal spraying powder of the present embodiment is at least 12.6 × 10 ⁻⁶ / at the maximum, as shown in the examples described later. Up to K is possible.

According to the present embodiment, the following advantages can be obtained.
・ When the ratio of molybdenum content to cobalt content in the cermet particles is in the range of 2.4 to 4.0, peeling from a substrate having a relatively large thermal expansion coefficient such as a stainless steel substrate. There is provided a powder for thermal spraying that is suitable for forming a thermal spray coating that is difficult to resist and has excellent resistance to melt damage. The ratio of the molybdenum content to the cobalt content is 4. In addition to preventing a decrease in the melt resistance of the thermal spray coating due to the ratio of the molybdenum content to the cobalt content being less than 2.4. This is because it is possible to prevent the thermal expansion coefficient of the thermal spray coating from being lowered due to being larger than 0.

  -Even when the chromium content in the cermet particles is in the range of 11 to 16% by mass and the cobalt content is in the range of 13 to 23% by mass, the thermal expansion coefficient is relatively similar to that of the stainless steel substrate. There is provided a thermal spraying powder suitable for forming a thermal spray coating that is not easily peeled off from a large base material and is excellent in resistance to melting. In addition to preventing the thermal expansion coefficient of the thermal spray coating from being lowered due to the chromium content being less than 11 mass% or the cobalt content being less than 13 mass%, the chromium content is 16 mass%. This is because it is possible to prevent a decrease in the thermal expansion coefficient and the resistance to erosion of the thermal sprayed coating resulting from the content exceeding 50% or the cobalt content exceeding 23% by mass.

A thermal spray coating having a thermal expansion coefficient of 9.5 × 10 ⁻⁶ / K or more in a temperature range of 100 to 600 ° C. formed by spraying the thermal spraying powder of the present embodiment is a base material made of stainless steel. In addition to being difficult to peel off from a substrate having a relatively large thermal expansion coefficient, it also has excellent resistance to erosion. This is because the thermal spraying powder of this embodiment contains cermet particles containing boron, molybdenum, chromium, and cobalt, as well as the thermal spraying powders of Patent Literatures 1 and 2. This is because the thermal expansion coefficient is larger than that of the thermal spray coating formed from the thermal spraying powder.

  When the ratio of the thermal expansion coefficient of the substrate in the temperature range of 100 to 600 ° C. to the thermal expansion coefficient of the thermal spray coating in the temperature range of 100 to 600 ° C. is in the range of 0.5 to 1.9, It is possible to suppress the peeling of the sprayed coating from. This is because it is possible to prevent the sprayed coating from peeling off from the substrate due to the difference between the thermal expansion coefficients of the substrate and the sprayed coating being too large.

You may change the said embodiment as follows.
The thermal spraying powder may contain elements other than cermet particles including boron, molybdenum, chromium, and cobalt. However, it is preferable that elements other than the cermet particles containing boron, molybdenum, chromium and cobalt contained in the thermal spraying powder are as few as possible.

  -When producing the thermal spraying powder, the granulated powder may be produced directly from the raw material powder, instead of producing the granulated powder from the raw material powder via a slurry. In this case, the granulated powder may be produced by rolling granulation or compression granulation instead of spray granulation.

  The thermal spraying powder may be manufactured by sintering and pulverizing a raw material powder containing boron, molybdenum, chromium, and cobalt. That is, the thermal spraying powder may be manufactured by compressing and molding the raw material powder and then sintering and pulverizing and classifying the obtained sintered body.

  -The raw material powder for thermal spraying is molybdenum boride powder such as molybdenum monoboride powder and dimolybdenum boride powder; chromium boride powder such as chromium monoboride powder and chromium diboride powder; tungsten carbide powder; chromium carbide Powder: Molybdenum carbide powder such as mono-molybdenum powder, di-molybdenum carbide powder; cobalt powder; cobalt alloy powder; chromium powder; chromium alloy powder; molybdenum powder; molybdenum alloy powder; tungsten powder; tungsten alloy powder and carbon powder It may be prepared by mixing several powders.

Next, the present invention will be described more specifically with reference to examples and comparative examples.
Cermet particles containing boron, molybdenum, chromium, and cobalt by granulating and sintering a raw material powder that is a mixture of mono-molybdenum boride powder, cobalt-based alloy powder (Stellite # 6 powder), and chromium diboride powder. Thermal spray powders of Examples 1 to 13 and Comparative Examples 1 to 6 were prepared. Details of each thermal spraying powder are as shown in Table 1.

In the column “Chemical component content in thermal spraying powder” in Table 1, the molybdenum content, boron content, chromium content, cobalt content, tungsten content and carbon content of the cermet particles in each thermal spraying powder Indicates. In the “Mo / Co” column of Table 1, the ratio of the molybdenum content to the cobalt content of the cermet particles in each thermal spraying powder is shown. The “Mo + B + Cr + Co” column in Table 1 shows the total of the molybdenum content, boron content, chromium content, and cobalt content of the cermet particles in each thermal spraying powder. The “crushing strength” column of Table 1 shows the crushing strength σ [MPa] of the cermet particles in each thermal spraying powder calculated according to the formula: σ = 2.8 × L / π / d ² . In the above formula, L represents the critical load [N], and d represents the average particle diameter [mm] of the cermet particles in each thermal spraying powder. The critical load is the magnitude of the compressive load applied to the cermet particles when the amount of displacement of the indenter increases rapidly when a compressive load increasing at a constant speed is applied to the cermet particles with the indenter. The critical load was measured using a micro compression test apparatus “MCTE-500” manufactured by Shimadzu Corporation.

  A base material made of SS400 steel plate that has been subjected to surface roughening treatment and degreasing treatment with alumina grit # 40 by spraying the thermal spraying powders of Examples 1 to 13 and Comparative Examples 1 to 6 under the conditions shown in Table 2. A thermal spray coating having a thickness of 500 μm was formed on the surface (70 mm × 50 mm × 2.3 mm), and the thermal expansion coefficient of the thermal spray coating in a temperature range of 100 to 600 ° C. was measured. Specifically, using a section of a sprayed coating having a size of 20 mm × 3 mm peeled off from a base material, heating from room temperature to 1000 ° C. at a heating rate of 20 K / min in an argon atmosphere, “Rigaku Co., Ltd.” Measured with TMA8310 ". The measurement results are shown in the “CTE” column of Table 1.

A base material made of alloy tool steel (SKD61) and a base material made of stainless steel (SUS316) are obtained by subjecting the powders for thermal spraying of Examples 1 to 13 and Comparative Examples 1 to 6 to high-speed flame spraying under the conditions shown in Table 2. A thermal spray coating was formed on the surface of each to prepare a laminate. The results of measuring the ratio of the thermal expansion coefficient of the base material in the temperature range of 100 to 600 ° C. to the thermal expansion coefficient of the thermal spray coating in the temperature range of 100 to 600 ° C. in each laminate are shown in “CTE / thermal spraying of base material” in Table 1. It is shown in the “CTE of film” column. In addition, the thermal expansion coefficient of the base material made from SKD61 is 13 × 10 ⁻⁶ / K, and the thermal expansion coefficient of the base material made from SUS316 is 18 × 10 ⁻⁶ / K.

  Based on the extent of spitting when each of the thermal spraying powders of Examples 1 to 13 and Comparative Examples 1 to 6 was subjected to high-speed flame spraying under the conditions shown in Table 2, excellent (◎), good (◯), acceptable ( (Triangle | delta)) Each powder for thermal spraying was evaluated in four steps of defect (x). Specifically, when adhesion of the melted powder for spraying was observed on the nozzle of the thermal sprayer at the time 10 minutes after the start of thermal spraying, it was poor, and no adhesion was observed at the time 10 minutes after the thermal spraying started. Is acceptable if adhesion is observed at 15 minutes, and no adhesion is observed at 15 minutes after the start of spraying, but adhesion is observed when adhesion is observed after 20 minutes. When adhesion was not recognized even at the time point 20 minutes after the start, it was evaluated as excellent. The evaluation results are shown in the “Spitting” column of Table 1.

  A base material made of SS400 steel plate that has been subjected to surface roughening treatment and degreasing treatment with alumina grit # 40 by spraying the thermal spraying powders of Examples 1 to 13 and Comparative Examples 1 to 6 under the conditions shown in Table 2. A sprayed coating was formed on the surface (250 mm × 75 mm × 2.3 mm), and the weight of the sprayed coating was measured. And based on the ratio of the weight of the thermal spray coating to the weight of the thermal spraying powder used for thermal spraying, that is, the adhesion efficiency, each of the four stages of excellent (◎), good (○), acceptable (△), and defective (×) The thermal spray powder was evaluated. Specifically, it is excellent when the adhesion efficiency is 45% or more, good when it is 40% or more and less than 45%, acceptable when it is 35% or more and less than 40%, and defective when it is less than 35%. evaluated. The evaluation results are shown in the “Adhesion efficiency” column of Table 1.

  The thermal spraying powders of Examples 1 to 13 and Comparative Examples 1 to 6 are subjected to high-speed flame spraying under the conditions shown in Table 2 to thereby make a bar made of alloy tool steel (SKD61) and a bar made of stainless steel (SUS316). A sprayed coating having a thickness of 200 μm was formed on the surface of the portion from the tip of the metal to 100 mm to prepare a specimen for a molten metal test. The diameter of each bar is 19 mm, the length of each bar is 200 mm, and the tip of each bar has a radius of curvature of 10 mm. For each specimen, an operation of immersing in a molten aluminum at 750 ° C. for 7.5 minutes, then pulling up from the molten metal and air-cooling for 1 minute was repeated until the thermal spray coating on the specimen surface was melted. In the molten metal, the specimen was rotated at 120 rpm and revolved at 30 rpm. Based on the results of this molten metal test, each thermal spraying powder was evaluated in four stages: excellent (◎), good (◯), acceptable (Δ), and poor (x). Specifically, when the time required for the melting to occur is less than 50 hours, it is defective, when it is 50 hours or more and less than 100 hours, it is acceptable, when it is 100 hours or more and less than 200 hours, it is good, 200 hours or more In the case of, it was evaluated as excellent. The evaluation results are shown in the “melting resistance” column of Table 1.

表１に示すように、比較例１〜６の各溶射用粉末から形成される溶射皮膜の熱膨張係数が９．５×１０^−６／Ｋよりも小さかったのに対し、実施例１〜１３の各溶射用粉末から形成される溶射皮膜の熱膨張係数はいずれも９．５×１０^−６／Ｋ以上であった。また、比較例１〜６の各溶射用粉末から形成される溶射皮膜のＳＵＳ３１６での耐溶損性に関する評価が不良であったのに対し、実施例１〜１３の各溶射用粉末から形成される溶射皮膜のＳＵＳ３１６での耐溶損性に関する評価はいずれも可以上であった。

As shown in Table 1, the thermal expansion coefficients of the thermal spray coatings formed from the thermal spraying powders of Comparative Examples 1 to 6 were smaller than 9.5 × 10 ⁻⁶ / K, whereas Examples 1 to 13 The thermal expansion coefficient of each thermal spray coating formed from each of the thermal spraying powders was 9.5 × 10 ⁻⁶ / K or more. Moreover, while the evaluation regarding the erosion resistance in SUS316 of the sprayed coating formed from each thermal spraying powder of Comparative Examples 1-6 was poor, it was formed from each thermal spraying powder of Examples 1-13. The evaluation regarding the erosion resistance of the thermal spray coating with SUS316 was all acceptable.

The technical idea that can be grasped from the embodiment will be described below.
(1) The thermal spraying powder according to any one of claims 1 to 3, wherein the total of the boron content, the molybdenum content, the chromium content, and the cobalt content in the cermet particles is 90% by mass or more. According to this, the erosion resistance of the thermal spray coating formed from the thermal spraying powder is improved.

  (2) The powder for thermal spraying according to any one of claims 1 to 3 and (1), wherein the crushing strength of the cermet particles is 100 to 600 MPa. According to this, the melt resistance of the thermal spray coating formed from the thermal spraying powder is improved, and the adhesion efficiency when the thermal spraying powder is sprayed is improved.

  (3) The thermal spraying powder according to any one of claims 1 to 3, and the above (1) and (2), which is used in an application for forming a thermal spray coating by high-speed flame spraying. According to this, the density of the thermal spray coating formed from the thermal spraying powder is improved.

(4) A thermal spray coating formed by spraying the thermal spraying powder according to any one of (1) to (3) above, and having a thermal expansion coefficient of 9.5 in a temperature range of 100 to 600 ° C. A sprayed coating that is at least 10 ⁻⁶ / K. According to this, peeling from the base material having a relatively large thermal expansion coefficient is suppressed.

  (5) The thermal spray coating according to claim 5, wherein the total of boron content, molybdenum content, chromium content and cobalt content in the cermet particles is 90% by mass or more. According to this, the erosion resistance of the thermal spray coating is improved.

  (6) The thermal spray coating according to claim 5 or (5), wherein the crushing strength of the cermet particles is 100 to 600 MPa. According to this, the melt resistance of the thermal spray coating is improved, and the adhesion efficiency when the thermal spray powder is sprayed is improved.

  (7) The thermal spray coating according to any one of claims 5 and (5) and (6), wherein the thermal spray coating is formed by high-speed flame spraying of a thermal spraying powder. According to this, the density of the thermal spray coating formed from the thermal spraying powder is improved.

Claims (6)

  A thermal spraying powder comprising cermet particles containing boron, molybdenum, chromium and cobalt, wherein the ratio of molybdenum content to cobalt content in the cermet particles is in the range of 2.4 to 4.0.   The thermal spraying powder according to claim 1, wherein the chromium content in the cermet particles is in the range of 11 to 16% by mass and the cobalt content is in the range of 13 to 23% by mass.   It contains cermet particles containing boron, molybdenum, chromium and cobalt, and the chromium content in the cermet particles is in the range of 11 to 16% by mass and the cobalt content is in the range of 13 to 23% by mass. Thermal spray powder. A thermal spray coating formed by spraying the thermal spraying powder according to any one of claims 1 to 3, wherein a thermal expansion coefficient in a temperature range of 100 to 600 ° C is 9.5 × 10 ^-6 / K. A thermal spray coating characterized by the above. A thermal spray coating formed by thermal spraying a thermal spraying powder containing cermet particles containing boron, molybdenum, chromium and cobalt, and having a thermal expansion coefficient of 9.5 × 10 ⁻⁶ / in a temperature range of 100 to 600 ° C. A thermal spray coating characterized by being K or higher. A thermal spray coating provided on the base material, and the thermal spray coating is formed by thermal spraying a thermal spraying powder containing cermet particles including boron, molybdenum, chromium, and cobalt. A laminate,
The ratio of the thermal expansion coefficient of the substrate in the temperature range of 100 to 600 ° C. to the thermal expansion coefficient of the thermal spray coating in the temperature range of 100 to 600 ° C. is in the range of 0.5 to 1.9. Laminated body.