JPH08311630A - Corrosion resistant and wear resistant self-fluxing alloy for thermal spraying - Google Patents

Abstract

PURPOSE: To obtain a corrosion resistant and wear resistant self-fluxing alloy material for thermal spraying having characteristics of both of excellent corrosion resistance and wear resistance in combination. CONSTITUTION: This first corrosion resistant and wear resistant self-fluxing alloy material contains 0.1 to 0.4wt.% C, 3.5 to 4.5wt.% Si, 18 to 20wt.% Cr, 16 to 18wt.% Mo, 1.5 to 2.5wt.% Cu, 2.5 to 3.5wt.% Fe, 0.1 to 0.4wt.% Mn and 3.0 to 4.0wt.% B and the balance Ni with inevitable impurities. The second corrosion resistant and wear resistant self-fluxing alloy material is a powder mixture composed of 35 to 50wt.% powder consisting of WC-Ni cermet particles or WC-NiCr cermet particles and the balance the self-fluxing alloy powder described above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-fluxing alloy material for thermal spraying which is excellent in corrosion resistance and wear resistance.

[0002]

2. Description of the Related Art As a material required to have corrosion resistance and abrasion resistance, for example, a plating solution (ZnS) is used in a continuous electroplating line for surface treatment of a surface-treated steel sheet for automobiles.
There are a current-carrying roll used as a cathode in contact with O ₄ + H ₂ SO ₄ ), a brush backup roll used in the pickling treatment after the surface treatment of the steel sheet, and the like. Since the energizing roll and the brush backup roll are required to have corrosion resistance against a plating solution or pickling solution and abrasion resistance against a steel plate with which they come into contact, casting of a Ni-Cr-Mo corrosion resistant alloy, chrome plating, Ni Although it is manufactured by a base self-fluxing alloy spray coating, etc., in recent years, in order to reduce the manufacturing cost of the steel sheet, the speed of the line is improved, the type of plating solution or acid solution, the usage conditions such as concentration and temperature are However, it is becoming more and more severe, and stricter characteristics than ever before are required. In the energizing roll and brush backup roll,
Materials having both of these properties are not known, such that materials with good corrosion resistance have poor wear resistance, while materials with good wear resistance have poor corrosion resistance. Therefore, since the service life reaches at most about 1 week to 1 month, it is necessary to stop the operation of the line for each short-term operation and perform a new replacement of the roll or re-polishing (repair) of the roll surface. However, this makes the line rotation rate low and significantly reduces the productivity of the steel sheet.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying, which solves the above-mentioned drawbacks and has both excellent corrosion resistance and wear resistance. The purpose is to do.

[0004]

In order to achieve the above object, the first corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to the present invention has a shape such as powder or rod, and is gas-type thermal spraying. It is suitable for applications such as C.
-0.4 wt%, Si 3.5-4.5 wt%, Cr 18-20 wt%, Mo 16-18 wt%, Cu 1.5-2.5 wt%, Fe 2 0.5-3.5% by weight,
It contains 0.1 to 0.4% by weight of Mn, 3.0 to 4.0% by weight of B, and the balance is Ni and inevitable impurities. In this corrosion- and wear-resistant self-fluxing alloy material, the sum of Cr and Mo is 37% by weight or less, and the sum of Cu and Fe is 4.5.
It is preferably at least wt%, and in the case of powder, the main particle size thereof is preferably within the range of 45 to 125 μm. The second corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying of the present invention is WC-Ni cermet particles or WC-NiC.
This is a mixed powder of 35 to 50% by weight of powder composed of r cermet particles and the rest of the self-fluxing alloy powder of the first aspect of the present invention. In this corrosion resistant / abrasion resistant self-fluxing alloy material, the main particle size of the spherical WC-Ni cermet particles and WC-NiCr cermet particles is preferably in the range of 45 to 125 μm.

[0005]

First, the first corrosion resistant / wear resistant self-fluxing alloy material of the present invention will be described. C: C is an element that mainly combines with Cr and Mo to form a double carbide to increase the hardness of the entire thermal spray coating and contribute to the improvement of wear resistance, but its content is 0.1% by weight. If it is less than%, sufficient wear resistance cannot be obtained because the amount of carbides is small. Further, excessive addition of more than 0.4% by weight results in an excessively large amount of double carbides being formed, resulting in deterioration of corrosion resistance and toughness, so the range is made 0.1 to 0.4% by weight. Si: Si is an essential element of the self-fluxing alloy material for thermal spraying together with B. In addition to acting as a deoxidizing agent, it also provides self-fluxing property, and further forms a solid solution in the matrix to provide hardness and wear resistance of the thermal spray coating. Contributes to the improvement of sex. If the content is less than 3.5% by weight, the above properties cannot be sufficiently obtained, and if it exceeds 4.5% by weight, the hardness becomes too high and brittle, and cracks are likely to occur during processing or use. Therefore, the range is 3.5
~ 4.5 wt%.

Cr: Cr combines with C to form a double carbide and also with B to form a double boride,
It is an essential element that enhances hardness and significantly improves corrosion resistance and abrasion resistance. If the content is less than 18% by weight, the formation of double carbides and double borides is insufficient and high corrosion resistance and wear resistance cannot be obtained, and if it exceeds 20% by weight, the toughness decreases, the melting point increases, and Since the solubility is lowered and defects such as blowholes are easily caused on the processed surface, the range is set to 18 to 20% by weight. Mo: Mo, like Cr, combines with C to form a double carbide and by combining with B to form a double boride,
It is an essential element that greatly improves the corrosion resistance and wear resistance. If the content is less than 16% by weight, the effect of forming the above-mentioned double carbide and double boride is small, and if it exceeds 18% by weight, further improvement of the effect cannot be expected.
On the contrary, since the toughness and the self-dissolving property are deteriorated, the content thereof is set to 16 to 18% by weight, which is less than the Cr content. When the total of Cr and Mo, which are elements of the same group, is 34 to 37% by weight, embrittlement of the thermal spray coating and deterioration of self-solubility are easily suppressed, which is preferable.

Cu: Cu is an essential element that forms a solid solution in the Ni matrix to enhance the strength of the entire thermal spray coating, promotes the formation of double carbides and double borides, and stabilizes the structure. Further, in a high temperature environment, due to the presence of Cu, these double carbides and double borides are in a stable state,
It is possible to obtain excellent corrosion resistance and abrasion resistance. If the content is less than 1.5% by weight, the amount of double carbide and double boride formed will be insufficient, and the desired corrosion resistance and wear resistance cannot be obtained. %, The effect of forming double carbides and double borides becomes too large, resulting in embrittlement of the sprayed coating, and further oxidation at high temperatures, so the range is made 1.5 to 2.5% by weight. . Fe: Fe is an element that forms a solid solution in the Ni matrix and improves the strength of the entire thermal spray coating as in the case of Cu. If the content is less than 2.5% by weight, the above-mentioned action is small, and if the content exceeds 3.5% by weight, the hardness of the sprayed coating is lowered, resulting in deterioration of corrosion resistance and wear resistance. Therefore, the content is 2.5 to 3.5% by weight. Further, the total of Cu and Fe is 4.5 to 6.0% by weight.
In that case, embrittlement of the thermal spray coating and deterioration of corrosion resistance and wear resistance due to the inclusion of Cr and Mo are easily suppressed, which is preferable.

Mn: Mn acts as a deoxidizer,
It is an element for improving the flowability of molten metal (fluidity of molten metal) during remelting treatment and promoting self-fluxing property, but if it is less than 0.1% by weight, the above-mentioned action cannot be obtained, and 0.4% by weight is required. If it is added in excess, it lowers the toughness of the thermal spray coating and also deteriorates the corrosion resistance, so the content is made 0.1 to 0.4% by weight. B: B, like Si, is an essential element of the self-fluxing alloy material for thermal spraying, and in addition to providing self-fluxing property, it is combined with Cr and Mo to form a Cr-Mo-Ni-based compound boride to form a thermal spray coating. It is an essential element that increases the overall hardness and contributes to the improvement of corrosion resistance and wear resistance. If the content is less than 3.0% by weight, sufficient corrosion resistance and abrasion resistance cannot be obtained because the amount of the complex boride formed is small, and addition in excess of 4.0% by weight results in formation of complex boride. Since the amount becomes too large and the toughness deteriorates, the range is 3.0 to 4.0% by weight. Ni: Ni is an element that forms the matrix (matrix) of the corrosion resistant and wear resistant self-fluxing alloy material of the present invention.

Next, the second corrosion resistant / wear resistant self-fluxing alloy material for thermal spraying of the present invention will be described. This corrosion- and wear-resistant self-fluxing alloy material is WC-Ni cermet particles or WC-N
Powder composed of iCr cermet particles 35 to 50% by weight
And the balance of the self-fluxing alloy powder of the first aspect of the present invention. WC was added to the self-fluxing alloy powder of the first aspect of the present invention.
By adding a powder composed of -Ni cermet particles or WC-NiCr cermet particles, the wear resistance can be further improved. When WC-Ni cermet particles or WC-NiCr cermet particles are added, their content is preferably 35 to 50% by weight. If it is less than 35% by weight, improvement in abrasion resistance is small, and if it exceeds 50% by weight, corrosion resistance is deteriorated, and further oxidation during re-melting treatment is intense, and defects such as blowholes and pinholes are sprayed. It tends to occur inside. Also,
The particle size of the WC-Ni cermet particles and the WC-NiCr cermet particles is preferably 45 to 125 μm. When it is less than 45 μm, fine particles are not uniformly distributed in the thermal spray coating during remelting treatment, and when it exceeds 125 μm, oxidation progresses and self-solubility decreases, and defects such as pinholes are likely to occur. .

Further, the WC-Ni cermet particles and the WC-NiCr cermet particles preferably have a spherical shape. Therefore, in order to produce WC-Ni cermet particles and WC-NiCr cermet particles, W
It is preferable to employ a granulation-sintering method in which an organic binder is added to a mixed powder obtained by mixing C powder and Ni powder or a Ni—Cr alloy powder, and then the mixture is granulated and then sintered at a high temperature. Particles produced by a casting-crushing method of crushing a molten ingot, a sintering-crushing method of crushing a sintered body, or the like are not preferable because the shape thereof is a square shape and the counterpart material in contact with the thermal spray coating is easily damaged. In the WC-Ni cermet particles, the content of Ni serving as a binder is 12 to 17% by weight.
Is preferred. If it is less than 12% by weight, the corrosion resistance is lowered, and if it exceeds 17% by weight, it is difficult to improve the abrasion resistance due to the low hardness of the particles. In the WC-NiCr cermet particles, the content of the Ni-Cr alloy serving as the binder is preferably 25 to 30% by weight. If the content is less than 25% by weight, toughness and corrosion resistance are reduced, and if it exceeds 30% by weight, wear resistance is reduced. Furthermore, this Ni
The Cr content% of the -Cr alloy is preferably 18 to 25% by weight.

[0011]

【Example】

[Examples 1 and 2] First, raw materials blended so as to have desired component compositions were vacuum-melted using a high-frequency induction vacuum melting furnace, and the obtained molten metal at about 1500 ° C was made into alloy powder by a water atomizing method. . After drying this alloy powder with hot air, it was classified to 45 to 125 μm with a vibration classifier to prepare a self-fluxing alloy material for thermal spraying. Table 1 shows the chemical composition of these alloy powders. These alloy powders were sprayed onto a stainless steel base material with a thickness of 3 mm by a powder type flame spray gun. Next, a combustion flame torch (oxygen-acetylene burner) is heated to 1000 ° C. or higher, remelting treatment is applied to form a self-fluxing alloy sprayed coating, and the surface of this coating is cut and polished to give a test piece. Was produced. After that, the hardness, wear resistance and corrosion resistance of each test piece were examined, and Table 2
The result shown in FIG.

The hardness test was carried out with Rockwell (C scale) and Micro Vickers (load 1 kg).
The wear test uses a Suga-type reciprocating motion wear tester and loads;
1 kg, number of reciprocations; 1600 times (DS (double stroke)), mating material: SiC # 320
Abrasion resistance WR (DS / mg) was determined by measuring the amount of abrasion loss in accordance with Item 9 (Reciprocating abrasion test method) of H8503 (Abrasion resistance test method for plating). Further, in the corrosion test, the size of the test piece was 2 × 10 × 30 mm, and the liquid temperature was 6
It was carried out in a 5 wt% sulfuric acid aqueous solution and a 5 wt% hydrofluoric nitric acid aqueous solution under conditions of 0 ° C. and a dipping time of 24 hours. Further, a specific resistance value was measured and a corrosion test in a plating solution under energization was performed. The corrosion test at this time was 30% by weight Z
Immersed in nSO ₄ +2 wt% H ₂ SO ₄ aqueous solution (60 ° C ±
5 ° C) as a cathode, current density 100 mA /
The current was applied at cm ² for 1 week and the corrosion weight loss was measured to determine the corrosion resistance. From the above, the results shown in Table 3 were obtained.

[Examples 3 to 5] First, in the same manner as in Example 1, self-fluxing alloy powder having the same components as in Example 1 was prepared. Table 1 shows the chemical composition of these self-fluxing alloy powders. Next, WC-12 wt% Ni powder and WC-25 wt%
NiCr powder was mixed with the above self-fluxing alloy powder at a mixing ratio shown in Table 1 to prepare a self-fluxing alloy material for thermal spraying. The above W
The C-12% by weight Ni powder is produced by a granulation-sintering method in which WC fine powder, Ni fine powder and an organic binder are mixed and granulated, and then sintered at a high temperature. ~
The particles are classified so as to fall within the range of 125 μm, and the particles have a spherical shape. Also, WC-25 wt% NiC
r powder is 25 wt% instead of 12 wt% Ni fine powder
WC-1 above except that Ni-Cr alloy fine powder was used.
It is produced in the same manner as the 2 wt% Ni powder, and the particle size and shape of the particles are the same as those of the WC-12 wt% Ni powder. Using these self-fluxing alloy materials for thermal spraying, the same tests as in Example 1 were performed after thermal spraying with a powder flame spray gun. The obtained results are shown in Tables 2 and 3.

[Conventional Example 1] A commercially available Ni-Cr-Mo alloy cast product was obtained. Table 1 shows the chemical composition of this cast product. Various characteristics of this cast product were measured in the same manner as in Example 1. The obtained results are shown in Tables 2 and 3. [Conventional Examples 2 to 4] A commercially available self-fluxing alloy material for thermal spraying was obtained. Table 1 shows the chemical composition of these alloy powders. Using these alloy powders, the same tests as in Example 1 were performed after spraying with a powder flame spray gun. The obtained results are shown in Tables 2 and 3. [Prior art example 5] A commercially available Cr-plated product was obtained. This Cr
Various characteristics of the plated product were measured in the same manner as in Example 1. The obtained results are shown in Tables 2 and 3.

[0015]

[Table 1] (wt%, balance: Ni) C Si B Cr Mo Fe Cu W Mn WC-Ni WC-NiCr WC-Co Example 1 0.38 4.4 3.2 18.4 17.8 2.6 2.3-0.2---Example 2 0.13 3.6 3.3 19.8 16.1 3.2 1.7-0.4---Example 3 0.30 3.9 3.5 18.8 16.7 2.9 2.1-0.1 35.0--Example 4 0.25 4.0 3.8 18.0 17.0 2.7 1.9-0.1 50.0--Example 5 0.20 4.2 4.1 19.5 16.5 3.4 2.0 -0.3-35.0-Conventional Example 1 0.02 0.1-16.3 17.1 5.2-4.3----Conventional Example 2 0.65 4.2 3.5 16.0 2.3 2.5 2.1-----Conventional Example 3 0.30 3.1 2.5 16.1-2.0-----50.0 Conventional example 4 0.70 4.4 2.7 13.9 1.2 3.8---35.0--Conventional example 5 C r

[0016]

TABLE 2 Hardness abrasion resistance 5% sulfuric acid 5% hydrofluoric nitric acid _{(H R C) (Hv)} (DS / mg) (g / m 2 · hr) (mg / cm 2 · day) Example 1 57 740 118 0.13 8.4 Example 2 58 765 125 0.11 7.9 Example 3 59 778 188 0.20 14.7 Example 4 60 792 213 0.25 14.8 Example 5 58 769 168 0.18 12.8 Conventional Example 1 H _R B90 201 33 0.09 5.8 Conventional Example 2 57 732 130 0.39 10.8 Conventional example 3 59 772 270 127.4 175.4 Conventional example 4 56 727 205 86.4 94.8 Conventional example 5 68 1080 127 108.5 152.2

[0017]

[Table 3]

From the results shown in Tables 2 and 3, the following can be seen. That is, the materials of Examples 1 to 5 are materials having both excellent corrosion resistance and abrasion resistance. On the other hand, the conventional materials have poor wear resistance when the corrosion resistance is good (conventional example 1), and poor corrosion resistance when the wear resistance is good (conventional examples 2 to 5). And one of the abrasion resistance is inferior.

[0019]

According to the present invention, it is possible to provide a corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying, which has both excellent corrosion resistance and wear resistance. Therefore, when the corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying of the present invention is used as a thermal spray coating material for electroplating energizing rolls, brush backup rolls, etc., it has excellent corrosion resistance and wear resistance, resulting in a long service life. Since the continuous operation time of the indicating line can be greatly extended, the effect of significantly improving the productivity of the steel sheet can be obtained.

Claims (8)

[Claims] 1. C of 0.1 to 0.4% by weight and Si of 3.
5 to 4.5 wt%, Cr 18 to 20 wt%, Mo 1
6-18% by weight, Cu 1.5-2.5% by weight, Fe 2.5-3.5% by weight, Mn 0.1-0.4% by weight,
A corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying, which contains 3.0 to 4.0% by weight of B, and the balance of Ni and unavoidable impurities. 2. The corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to claim 1, wherein the sum of Cr and Mo is 37% by weight or less. 3. The corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to claim 1, wherein the sum of Cu and Fe is 4.5% by weight or more. 4. The corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to claim 1, 2 or 3, which has a powder form. 5. The corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to claim 1, 2 or 3, which has a rod shape. 6. The main particle size of the powder particles is 45 to 125 μm.
5. The corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to claim 4, which is within the range. 7. A powder 35 to 5 comprising spherical WC-Ni cermet particles or WC-NiCr cermet particles.
A corrosion resistant and wear resistant self-fluxing alloy material for thermal spraying, which is a mixed powder of 0 wt% and the balance of the self-fluxing alloy powder according to claim 4 or 6. 8. The main particle size of the spherical WC-Ni cermet particles or WC-NiCr cermet particles is 45-45.
The corrosion-resistant and wear-resistant self-fluxing alloy material for thermal spraying according to claim 7, which is in a range of 125 μm.