JPH10121221A - Wear resistant and corrosion resistant metallic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a member free from defects such as oxides and circular openings at the inside and excellent in wear resistance and corrosion resistance by thermally spraying high carbon iron base alloy powder in which the contents of Cr, V, Ni, Mo and Si are specified on the surface of a metallic member. SOLUTION: On the surface of a metallic member, the thermally sprayed coating film of high carbon iron base alloy powder contg., by weight. 3.0 to 6.0% C, 5.0 to 15.0% Cr, 5.0 to 8.0% V, 2.0 to 6.0% Ni, 0.5 to 3.0% Mo, 1.0 to 4.0% Si, and the balance Fe is formed by a thermal spraying method. If required, at least one kind selected from 0.05 to 0.5% B, 0.01 to 0.5% Al, 0.01 to 0.8% Ti, 0.03 to 0.5% Mn and 0.1 to 0.5% P is incorporated into the alloy powder. At the time of executing heating treatment at 300 to 500 deg.C after the formation of the sprayed coating, the sprayed coating is made dense to improve its hardness by about 150 to 300HV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear-resistant and corrosion-resistant metal member having a sprayed coating having excellent wear resistance and corrosion resistance.

[0002]

2. Description of the Related Art As is well known, high carbon iron-based alloys are used for papermaking,
2. Description of the Related Art In various plants such as steelmaking and chemistry, it is widely used for various structural members for the purpose of improving wear resistance and corrosion resistance. As high carbon iron-based alloys used for such purposes, Japanese Patent Application Laid-Open Nos. Hei 1-2201438 and Hei 1-3
No. 19622 and JP-A-2-141560, and iron-based ceramic materials disclosed in JP-A-6-240.
There is a tough high carbon cementite alloy cast iron disclosed in Japanese Patent No. 404, all of which are used as cast members.

On the other hand, Japanese Patent Publication No. 6-65747 discloses that
A metal member having a thermal spray coating formed by using a thermal spray material cast in a rod shape is disclosed.

[0004]

However, the above-mentioned iron-based ceramic materials and tough high-carbon cementite-based alloy cast irons cannot be sufficiently degassed depending on the casting method, so that gas remains inside the cast member and shrinkage cavities are formed. There is a problem that casting defects such as generation are liable to occur, and a problem that the cooling rate is slow, the structure is coarsened, and the segregation of components is caused, and the variation in hardness is increased. Also, there is a problem that the cutting property is very poor due to large variation in hardness and hardness, and it takes a long time for cutting. Further, there is a problem that if a defect exists in the cast member, it cannot be repaired or regenerated. As described above, the casting method has many problems in practical use.

On the other hand, in the metal member having the thermal spray coating, since the thermal spray material cast into a rod shape is used, it is necessary to sufficiently melt the thermal spray material. Therefore, the transport speed of the rod must be extremely low. In addition, there is a problem that it is necessary to attach a special speed reducer to the spraying machine, and the material cost of the bar-shaped sprayed material is relatively high, and the bar length is short, so that the sprayed material cannot be continuously supplied. There are also problems such as a large number of oxides and vacancies in the thermal spray coating.

The inventors of the present invention have sought to realize a member having a thermal sprayed coating which is free from defects such as oxides and voids inside the member, has good cutting properties, and is excellent in wear resistance and corrosion resistance. As a result of repeated research and experiments, the sprayed coating formed by spraying high carbon iron based alloy powder of a specific composition has a finer structure than the cast member, and the formed sprayed coating has a shrinkage cavity due to the laminated structure The above technical problem was achieved by obtaining remarkable knowledge that there is no internal defect such as the above, the variation in hardness is small, the machinability is excellent, and partial repair is possible.

[0007]

The technical problem can be solved by the present invention as described below.

[0008] That is, the wear-resistant and corrosion-resistant metal member according to the present invention has a C 3.0 surface on the surface of the metal member by the powder spraying method.
6.0% by weight, Cr 5.0-15.0% by weight, V 5.0-8.0% by weight, Ni 2.0-6.0% by weight, Mo 0.5-3.0% by weight, Si 1.0
~ 4.0 wt%, with a thermal spray coating of a high carbon iron-based alloy powder consisting of the balance Fe.

Further, the wear-resistant and corrosion-resistant metal member according to the present invention has a B 0.02
5 to 0.5% by weight, Al 0.01 to 0.5% by weight, Ti 0.01 to 0.
8% by weight, at least one selected from Mn 0.03 to 0.5% by weight and P 0.1 to 0.5% by weight, C 3.0 to 6.0% by weight,
Cr 5.0-15.0% by weight, V 5.0-8.0% by weight, Ni 2.0-6.
0 wt%, Mo 0.5-3.0 wt%, Si 1.0-4.0 wt%,
A sprayed coating of a high-carbon iron-based alloy powder consisting of the balance Fe is formed.

Further, the present invention relates to any one of the above-mentioned abrasion-resistant and corrosion-resistant metal members, wherein after forming the thermal-sprayed film, 300 to 50%.
It has been subjected to a heat treatment of 0 ° C.

[0011]

Embodiments of the present invention will be described below.

First, the composition of the high-carbon iron-based alloy powder will be described in detail. C forms a carbide by bonding with Fe and Cr,
Part of the solid solution in Fe has the effect of increasing the hardness of the thermal sprayed coating and improving the wear resistance. However, if the content is less than 3.0% by weight, this effect is not obtained, and if it exceeds 6.0% by weight, the toughness is significantly reduced. . Therefore, its content is preferably 3.0 to 6.0% by weight.

[0013] Since Cr forms carbides by combining with C, the hardness of the thermal sprayed coating is increased, thereby improving the wear resistance and the corrosion resistance. If less than 5.0% by weight, this effect is obtained. Is not obtained, and if it exceeds 15.0% by weight, the toughness decreases. Therefore, its content is preferably set to 5.0 to 15.0% by weight.

V forms a carbide by bonding with C in the same manner as Cr and Fe, so that the hardness of the thermal sprayed coating increases and the wear resistance is improved. If less than 5.0%, this effect is not obtained. If not more than 8.0%, the toughness decreases. Therefore, its content is preferably set to 5.0 to 8.0% by weight.

[0015] Ni has the effect of improving the adhesion and toughness of the sprayed coating, but if it is less than 2.0% by weight, this effect cannot be obtained, and if it exceeds 6.0% by weight, it tends to soften. Therefore, its content is preferably set to 2.0 to 6.0% by weight.

Mo, which forms a solid solution in Fe, has the effect of increasing the hardness of the thermal sprayed coating and improving the corrosion resistance. However, if it is less than 0.5% by weight, this effect cannot be obtained. The toughness is reduced due to precipitation as an intermetallic compound. Therefore, its content is preferably 0.5 to 3.0% by weight.

Since Si prevents the powder from being oxidized during thermal spraying, it has the effect of improving the adhesion of the thermal sprayed coating and increasing the hardness. However, if it is less than 1.0% by weight, these effects cannot be obtained. If the content exceeds% by weight, the toughness decreases. Therefore, its content is preferably set to 1.0 to 4.0% by weight.

B, like Si, prevents the powder from being oxidized during thermal spraying, and thus has the effect of improving the adhesion of the thermal sprayed coating. However, if it is less than 0.05% by weight, this effect cannot be obtained. If it exceeds, the toughness decreases. Therefore, its content is 0.
It is preferably between 0.05 and 0.5% by weight.

Al also prevents the oxidation of the powder during thermal spraying like Si, and thus has the effect of improving the adhesion of the thermal sprayed coating. However, if it is less than 0.01% by weight, this effect cannot be obtained. If it exceeds, the adhesiveness of the thermal spray coating decreases. Therefore, its content is preferably 0.01 to 0.5% by weight.

Ti also has the same effect as Al. However, if it is less than 0.01% by weight, this effect cannot be obtained, and if it exceeds 0.8% by weight, the adhesion of the thermal sprayed coating is conversely reduced. .
It is preferably from 0.01 to 0.8% by weight.

Mn is added as a desulfurizing agent. However, if it is less than 0.03% by weight, this effect is not obtained, and if it exceeds 0.5% by weight, the toughness is reduced.
% By weight.

P improves the adhesion of the thermal sprayed coating and prevents hot cracking. However, if the content is less than 0.1% by weight, this effect cannot be obtained. If the content exceeds 0.5% by weight, the toughness decreases. , Its content is preferably 0.1 to 0.5% by weight.

The high-carbon iron-based alloy powder having the above composition can be produced by a conventional method by powdering the molten metal. In particular, the molten metal is discharged from the fine pores and the falling molten metal is discharged from the nozzle by air or inert gas. It is most suitable to manufacture by the atomization method (powder atomization method), which produces powder by spraying with gas or water, since it is possible to mass-produce high-purity spherical powder with very little oxide of metal powder. By doing so, the fluidity is good, a stable supply from the powder feeder to the spraying machine can be obtained, and oxidation during spraying can be minimized. Also, if the powder particle size is 45 to 75 μm, it is suitable for plasma spraying using a plasma arc as a heat source.
If it is set to 45 μm, it can be used for high-speed flame spraying, in which the flame temperature serving as a heat source is lower than that of plasma spraying.

The thermal spray coating can be formed according to a conventional method employed for thermal spraying of a high carbon iron-based alloy powder on the surface of a metal member. In addition to the above-described plasma thermal spraying method and high-speed flame thermal spraying method, a thermal spraying method using a D gun can be used. Applicable. The plasma spraying method and the high-speed flame spraying method can inject powder at a high speed at high temperature and shorten the contact time with air.
Oxidation of the powder particles can be prevented, a sufficient molten state can be obtained, and the film becomes dense, so that the adhesion to the member is good.

The thermal spraying conditions for forming the thermal spray coating by the plasma thermal spraying method include, for example, a thermal spraying output of 30 Kw, a thermal spraying current of 180 A, a thermal spraying voltage of 170 V, a plasma gas of argon, and a thermal spraying distance of 130 mm. The powder supply amount may be 12 g / min, and the powder supply gas may be argon.

The thermal spraying conditions for forming the thermal spray coating by the high-speed flame spraying method include, for example, a gas pressure of 10.3ba oxygen.
r, propylene 6.9 bar, air 5.2 bar, gas flow rate 310 l / min oxygen, 75 l / min propylene, air
What is necessary is just to set 345 liter / min, the spraying distance to 200 mm, the powder supply amount to 50 g / min, and the powder supply gas to nitrogen.

If the coating is heated in an electric furnace at a temperature of 300 to 500 ° C. for 8 to 10 hours after the formation of the thermal spray coating, the thermal spray coating is densified and the hardness is improved by about HV 150 to 300.

[0028]

Embodiments of the present invention will be described below.

Examples 1 to 12 and Comparative Examples A to D.

Six types of high-carbon iron-based alloy powders shown in Table 1 were produced by a nitrogen gas atomizing method. In addition, the balance of Fe contains unavoidable impurities.

[0031]

[Table 1]

Examples 1 to 6: Each alloy powder shown in Table 1 (powder in Example 1, powder in Example 2, powder in Example 3, powder in Example 4, powder in Example 5, powder in Example 5, Is powder), and the thickness is 0.3 to 0.5m on the SS400 plate of 60mm × 40mm × 5mm by high-speed gas flame spraying method.
m-spray coating was formed to obtain a SS400 plate-shaped test piece. Each test piece and each test piece are further placed in an electric furnace at a temperature of 450 ° C.
A hardness test and a wear test were performed on each of the test pieces subjected to the heat treatment for 10 hours. Also, for comparison, SUS316L
Each test similar to the above was performed using a plate piece (Comparative Example A) and a cast material piece (Comparative Example B) having the same composition as the alloy composition shown in Table 1. Table 2 shows the results.

The spraying conditions for the high-speed gas flame spraying method are as follows: gas pressure: oxygen 10.3 bar, propylene 6.9 bar, air 5.2 ba
r, gas flow rate: oxygen 310 l / min, propylene 75 l / min, air 345 l / min, spraying distance: 200mm
, Powder supply amount: 50 g / min, powder supply gas: nitrogen.

The hardness test was carried out using a micro Vickers hardness tester (measuring load 4.903 N) after polishing the surface of the sprayed coating of each test piece to # 1000 with a water-resistant abrasive paper. The abrasion test was performed by polishing the surface of the sprayed coating of each of the test pieces to # 1000 with a water-resistant abrasive paper, and then using a suga type abrasion tester (JIS H 85
03 Test load: 3 kgf, abrasive paper: SiC-grain size # 120, number of friction: 3,20
A wear test was performed under the condition of 0DS (1DS is one-way friction), and the wear loss after the test was measured.

[0035]

[Table 2]

From Table 2, it was confirmed that each of the test pieces of Examples 1 to 6 was superior to the SUS316L plate piece of Comparative Example A in abrasion resistance.

Examples 7 to 12: Alloy powders shown in Table 1 (powder in Example 7, powder in Example 8, powder in Example 9)
Powder in Example 10, powder in Example 11, powder in Example 11, and powder in Example 12) under the same spraying conditions as in Examples 1 to 6 by a high-speed gas flame spraying method.
A 0.3 to 0.5 mm thick sprayed coating was formed on the surface of a φ120 mm SUS wire to obtain a linear SUS specimen. A corrosion test and a machinability test were performed on each of the test pieces and each of the test pieces which were further subjected to a heat treatment in an electric furnace at a temperature of 450 ° C. for 10 hours. For comparison, SUS316L wire piece (Comparative Example C)
Each of the same tests as described above was performed using the above and a cast piece (Comparative Example D) having the same composition as the alloy composition shown in Table 1. Table 3 shows the results.

In the corrosion test, a 100 ml test tube containing concentrated hydrochloric acid (liquid temperature 25 ± 1 ° C.) and a concentrated sulfuric acid (liquid temperature 25 ± 1 ° C.) were used.
Each of the test pieces was placed in a 0 ml test tube, immersed for 24 hours, taken out, washed, dried, and the corrosion weight loss was measured. In the machinability test, the sprayed SUS linear test piece was cut using a carbide tool, and the time required to reach a predetermined dimension was measured. In the evaluation of the machinability, the time required for cutting each test piece was shown as a relative value, with the time required for cutting the cast material piece taken as 100.

[0039]

[Table 3]

From the test results shown in Table 3, Examples 7 to 12
It was confirmed that each of the test pieces was superior in corrosion resistance to the SUS316L wire piece in Comparative Example C, and superior in machinability to the cast material piece in Comparative Example D.

Embodiment 13 FIG.

The inner part of the tapered roller bearing of the steel strip rolling roller bearing was undercut, and this part was blasted, then heated to a temperature of 80 ° C., and the powder shown in Table 1 was used in the blast processing part. A sprayed coating having a thickness of 150 to 250 μm was formed by the plasma spraying method. Further, the surface of the thermal spray coating was sealed with an epoxy resin.

Abrasion resistance was obtained in the inner part, and good results were obtained in an actual environment.

The spraying conditions of the plasma spraying method are as follows: spraying power: 30 Kw, spraying current: 180 A, spraying voltage: 170 V, plasma gas: argon, spraying distance: 130 mm, powder supply amount: 12
g / min, powder supply gas: argon.

Embodiment 14 FIG.

After repairing the abrasion generated at the contact portion of the end surface of the hot rough roll with the brass wheel seal, this portion was blasted by a hand-type blasting device, and then under-coated with Ni-Al powder. The undercoat portion was coated with the powder shown in Table 1 by plasma spraying under the same spraying conditions as in Example 13 to a thickness of 100 to 200 μm.
Was formed. After the thermal spraying, the surface was finished using a precision polishing machine and a polishing grindstone, and then heated at a temperature of 400 ° C. for 8 hours to increase the hardness of the thermal sprayed coating.

Abrasion resistance was obtained at the contact portion of the roll end surface with the brass wheel seal, and good results were obtained in an actual environment.

Embodiment 15 FIG.

Repair work was carried out to prevent corrosion of each part of the wastewater treatment tower by wastewater. The portion where pitting occurred was ground with a grinder, and Ni-Cr was sprayed as an undercoat, and a mixed powder of 50 parts by weight of powder shown in Table 1 and 50 parts by weight of TiO ₂ powder was applied to the undercoat. A sprayed coating having a thickness of 100 to 200 μm was formed by a high-speed gas flame spraying method under the same spraying conditions as in Examples 1 to 6. Further, the surface of the thermal spray coating was sealed with a phenol resin.

The corrosion of each part of the wastewater treatment tower was prevented, and good results were obtained in an actual environment.

Embodiment 16 FIG.

The outer periphery of the sleeve for connecting the motor part and the pump part of the pump used in the muddy water was worked to prevent corrosion. After blasting the surface of the sleeve of the muddy water pump, the sprayed coating having a thickness of 150 to 250 μm was applied to the blasted portion by the plasma spraying method using the powder shown in Table 1 under the same spraying conditions as in Example 13. Was formed. After thermal spraying, the surface was finished using a precision polishing machine and a polishing grindstone.

Corrosion of the outer periphery of the sleeve for joining the motor part and the pump part of the muddy water pump was prevented, and good results were obtained in an actual environment.

[0054]

As described above, according to the present invention, a general-purpose powder spraying machine such as a plasma spraying machine or a high-speed flame spraying machine can be used. , And a wear-resistant and corrosion-resistant metal member having a sprayed coating having excellent wear resistance and corrosion resistance formed thereon can be manufactured at low cost.

Therefore, it can be said that the industrial applicability of the present invention is very high.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Masakatsu Magome 2116-1 Komeicho, Ikoma, Nara Prefecture Within Kogyo Co., Ltd. (72) Inventor Kanichi Kanichi

Claims (3)

[Claims] 1. The method according to claim 1, wherein the surface of the metal member is powder-sprayed.
C 3.0-6.0% by weight, Cr 5.0-15.0% by weight, V 5.0-8.
0 wt%, Ni 2.0-6.0 wt%, Mo 0.5-3.0 wt%,
A wear-resistant and corrosion-resistant metal member having a sprayed coating of a high-carbon iron-based alloy powder composed of 1.0 to 4.0% by weight of Si and the balance of Fe. 2. The surface of a metal member is sprayed by powder spraying.
B 0.05-0.5 wt%, Al 0.01-0.5 wt%, Ti 0.0
1 to 0.8% by weight, Mn 0.03 to 0.5% by weight and P 0.1 to 0.
At least one selected from 5% by weight, C 3.0 to 6.0% by weight, Cr 5.0 to 15.0% by weight, V 5.0 to 8.0% by weight, Ni
2.0-6.0% by weight, Mo 0.5-3.0% by weight, Si 1.0-4.0
A wear-resistant and corrosion-resistant metal member, characterized in that a thermal spray coating of a high-carbon iron-based alloy powder composed of wt% and the balance of Fe is formed. 3. The wear-resistant and corrosion-resistant metal member according to claim 1, wherein a heat treatment at 300 to 500 ° C. is performed after the formation of the thermal spray coating.