JP2995512B2 - Lubricant spontaneous formation type sliding member and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant spontaneously forming type slide suitable for preventing damage such as abrasion, adhesion or peeling between surfaces which contact or slide with each other in Na. The present invention relates to a member and a method for manufacturing the member.

[0002]

2. Description of the Related Art In general, sodium is widely used industrially. For example, in a fast breeder reactor in the nuclear industry, sodium is used as a medium for transmitting heat energy generated in a core to a heat exchanger for converting water into steam. Used. It is also well known that the nature of sodium is chemically very active and shows strong reducing properties. For this reason, the structural material of the sodium environmental device is different from the material used in the air or water, and the selection range of usable materials is severely restricted. In particular, for members that contact or slide with each other in sodium, the oxide film formed on those surfaces is reduced by sodium to expose the metal background, and the constituent elements of both members are easily exposed via the contact surface. Diffusion causes the two members to fuse and wear as if they were welded. Such fusing or abrasion of the members causes a problem in maintenance and safety of the sodium environmental equipment.

When a chromium-based material is immersed in sodium, sodium chromite (NaCrO ₂ ), which is chemically stable even in sodium, may be formed on the surface depending on environmental conditions. Sodium chromite is
Since the crystal structure is hexagonal and the intermolecular force of the close-packed surface is weak, it is expected to play a role as a lubricant in the sliding portion. Since this sodium chromite is generated or decomposed depending on the oxygen concentration and temperature in sodium, zirconium or titanium, which easily absorbs oxygen, is mixed with chromium and coated on the substrate surface, so that sodium chromite is easily formed The method is described in JP-A-58-210160.

[0004] However, when the above-mentioned structural member is used in a sodium environment, there is a concern that when the oxygen concentration in sodium is low, the function of the oxygen storage material cannot be exhibited, and there is a possibility that sodium chromite may not be formed. It depends heavily on conditions. In particular, in a fast breeder reactor, sodium tends to be highly purified in order to reduce corrosion of used equipment materials, and it is more difficult to form stable sodium chromite. Therefore, regardless of the oxygen concentration in sodium, that is, regardless of environmental conditions, sodium chromite is formed on the surface of the sliding member, and the surface treatment of the metal material which has been subjected to a surface treatment capable of improving the fusion resistance and abrasion resistance. Appearance was desired.

[0005] It is also known to reduce the corrosion and abrasion caused by the liquid alkali metal by depositing and coating a support surface made of a nickel-chromium alloy having a support surface or a friction surface in contact with each other with alumina or aluminide. -2116
No., published in Japanese Patent Application Publication No. In addition, JP-B-53-33946 describes a method for producing a bearing alloy having a structure in which lead or the like is infiltrated into pores of a sprayed layer and has a good distribution.

[0006]

In the above prior art, there is disclosed a method in which zirconium or titanium, which easily absorbs oxygen, is mixed with chromium and coated on the surface of the base material to facilitate formation of sodium chromite. Although disclosed in the 210160 gazette, when this structural member is used in a sodium environment, if the oxygen concentration in sodium is low, the function of the oxygen storage material cannot be exerted, and sodium chromite may not be formed. In the fast breeder reactor, since high-purity sodium is used, there is a problem that stable sodium chromite is hardly formed.

An object of the present invention is to provide a sliding member used in liquid Na on a surface of NaCrO ₂ having lubricating action.
It is an object of the present invention to provide a lubricant spontaneously-forming type sliding member which can be spontaneously formed without being affected by the oxygen concentration in the inside and continuously supply NaCrO ₂ to the sliding surface, and a method of manufacturing the same.

[0008]

In order to achieve the above object, the first lubricant spontaneously forming type sliding member of the present invention is a sliding member used in a sodium environment, and is made of stainless steel material. And a substrate formed on the surface of the substrate,
And a coating layer made of chromium carbide mixed with chromium oxide.

A second lubricant spontaneously forming type sliding member according to the present invention is characterized in that the first lubricant spontaneously forming type sliding member uses a nickel-based alloy instead of chromium carbide.

[0010] The third lubricant spontaneously forming type sliding member of the present invention is a sliding member used in a sodium environment, and has a base made of a stainless metal material and pores on the surface of the base. And a chromium oxide impregnated in the pores of the coating layer.

A fourth lubricant spontaneously forming type sliding member according to the present invention is characterized in that the first lubricant spontaneously forming type sliding member uses a nickel-based alloy instead of chromium carbide.

Further, a fifth lubricant spontaneously forming type sliding member of the present invention is a sliding member used in a sodium environment, comprising a base made of a stainless metal material having pores,
And chromium oxide impregnated into pores in the substrate.

[0013] The first to fifth lubricant spontaneously forming type sliding members of the present invention are characterized in that, in liquid sodium, chromium oxide combines with sodium to form a sodium composite oxide (N
aCrO ₂ ).

According to another aspect of the present invention, there is provided a method of manufacturing a lubricant spontaneously forming type sliding member according to the present invention, which comprises manufacturing a sliding member used in a sodium environment. Is coated with a mixture of chromium carbide powder or nickel-based alloy powder and chromium oxide powder to form a surface layer. It is preferable to use a thermal spraying method as a coating method.

Further, another method of manufacturing a lubricant spontaneously forming type sliding member of the present invention is a method of manufacturing a sliding member used in a sodium environment, wherein a chromium carbide is formed on a surface of a substrate made of a stainless metal material. Powder or nickel-based alloy powder is sprayed to form a surface layer having pores, chromium oxide in a slurry state is applied to the surface layer to impregnate the pores, and then fired.

Still another method of manufacturing a sliding member of the present invention is a method of manufacturing a sliding member used in a sodium environment, wherein the surface of a sintered or foamed stainless metal material is provided. Is characterized in that chromium oxide in the form of a slurry is applied to impregnate pores and fired.

[0017]

When the lubricant spontaneously forming type sliding member of the present invention is immersed in liquid sodium, chromium oxide in the sliding member is combined with sodium to form a sodium composite oxide NaCr.
Generate O ₂ . Although NaCrO ₂ is thermodynamically stable even in Na, its crystal structure is hexagonal and the bonding force of molecules between hexagonal planes is weak, so that it is sheared therefrom. That is, since NaCrO ₂ easily undergoes shear plastic deformation, it exhibits a solid lubricating action. By spontaneously forming NaCrO ₂ having a lubricating effect on the sliding surface, direct contact of the metal substrate can be prevented and adhesive wear can be suppressed. As a result, a low friction coefficient and a low wear amount are achieved. it can.

However, since NaCrO ₂ has poor adhesion to the metal substrate, it is easily discharged from the sliding surface during use. Therefore, in order to achieve a low friction coefficient and a low wear amount, and to achieve a long life, a material having good compatibility with Na, that is, a sliding member in which chromium carbide or a nickel-based alloy and chromium oxide are mixed is used. Even if NaCrO ₂ is discharged from the sliding surface or wear occurs during use, NaCrO ₂ is continuously supplied from the inside of the material, or chromium oxide appears on the sliding surface and comes in contact with Na, spontaneously generating NaCrO ₂ Therefore, the lubricating action can be maintained for a long time.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The lubricant spontaneously forming type sliding member according to the present invention is basically applicable to all sliding members used in Na, and is applied to at least one of two members sliding with each other. Used. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partial sectional view showing a first embodiment of a sliding member (hereinafter simply referred to as a sliding member) according to the present invention. The sliding member of the present embodiment is a metal base 1
And a coating layer 2 formed on the surface of the metal substrate 1 and containing chromium oxide 4 therein.
The metal substrate is made of Ni-Cr or Cr-based stainless steel, and the coating layer 2 is made of chromium oxide or nickel-base alloy, which is mainly mixed with chromium oxide 4 in an appropriate amount. In FIG. 1, the work-affected layer 3 interposed between the metal base 1 and the coating layer 2 has crystal grains refined by blasting for improving the adhesion during the formation of the coating layer 2. , A part of the metal substrate 1. The metal substrate is not limited to the above stainless steel, and a material having corrosion resistance and high-temperature strength in Na can be used. The coating material is not limited to the chromium carbide and the nickel-based alloy, and the corrosion resistance in Na, Any material may be used as long as it has good adhesion to the substrate and hardness.

Next, a method of manufacturing the sliding member of the first embodiment will be described. First, the surface of the metal substrate 1 is blasted to improve the adhesion to the coating layer formed in the next step. Then, a coating material having a predetermined thickness is sprayed on the surface of the blasted metal substrate by a plasma or explosive gun, and a coating material, that is, a material obtained by mixing chromium oxide or a nickel-based alloy with chromium oxide, is sprayed on the surface. Forming layer.

The surface-modified sliding member is made of Na
When immersed in, chromium oxide appearing on the surface
And spontaneously convert to NaCrO ₂ . When slippage occurs between the sliding member and the mating material, the spontaneously generated NaCrO ₂ undergoes shear plastic deformation to exhibit a lubricating action.

In order to verify these series of phenomena, basic tests were carried out on the spontaneous formation of NaCrO ₂ by chromium oxide, the form of wear after the formation of the NaCrO ₂ film and the wear characteristics. In this basic test, to confirm that chromium oxide spontaneously converts to NaCrO ₂ in Na,
Using a test piece obtained by plasma spraying only chromium oxide (Cr ₂ O ₃ ) on the surface of stainless steel, and purifying Na up to 120 ° C. at a cold trap temperature to obtain 1 ppm of dissolved oxygen N
a was heated to 500 ° C., and the test piece was immersed therein for 100 h. After completion of the immersion, the test piece is taken out of Na,
An X-ray diffraction test was performed. As a result, although NaCrO ₂ was spontaneously formed, it was found that there was a problem in the adhesion between the chromium oxide layer and the stainless steel.

Next, using a pin-disk type test piece,
The wear mode of the aCrO ₂ coating was examined. In this test, a film of NaCrO ₂ was formed on a disk type test piece in Na, and then a pressing load of a maximum of 200 g was applied to the pin side, and the sliding state was observed online in a scanning electron microscope.
Further, for comparison, a test using a disk-type stainless steel test piece having no NaCrO ₂ film was also performed. As a result, in the case of a stainless steel test piece, wedge-shaped wear particles are generated at the leading edge of the pin, grow while adhering to the pin, and wear while repeating a phenomenon of detachment when reaching a critical diameter. In contrast, in the disk-type test piece having a NaCrO ₂ film, the wear particles does not occur, friction marks caused been squashed coating NaCrO ₂ only (shear plastic deformation marks) were observed, the NaCrO ₂ The lubrication effect that has was confirmed.

Further, in order to examine the sliding characteristics of the NaCrO ₂ film in Na, a material obtained by uniformly mixing a small amount of chromium oxide mainly with chromium carbide was sprayed onto the surface of stainless steel with an explosion gun, and the temperature was raised to 550 ° C. A sliding test was performed in Na. For comparison, a sliding test between the materials subjected to thermal spraying was performed in the atmosphere. In the test, a pressing load of 0.3 kg / mm ² was applied to the as-sprayed materials to make a sliding distance ± 5 mm. As a result, the coefficient of kinetic friction at room temperature and in the atmosphere was about 0.8, but was improved to about 0.3 after being immersed in Na at 550 ° C. for 100 hours.
It was confirmed that the low coefficient of friction could be stably maintained even with zero or more slides.

From the results of the above basic tests, NaCr
O ₂ is easily converted from chromium oxide (Cr ₂ O ₃ ) in Na,
In addition, the spontaneous generation of NaCrO
No. ₂ shows a lubricating action in Na, and further, by mixing chromium oxide in chromium carbide, which is a material having good compatibility with Na, NaCrO ₂ is continuously used in Na even if the sliding surface is worn. It was confirmed that it was formed as a target and exhibited a lubricating effect for a long period of time.

FIG. 2 is a view showing an example in which the sliding member of the present invention is applied to a pad portion of a fuel assembly wrapper tube in a fast breeder reactor, and FIG. 3 is a sectional view taken along line AA of FIG. . The fuel assembly includes a number of fuel rods 6, a wrapper tube 7, a handling head 8, an entrance nozzle 9, a spacer pad 10, and the like. The wrapper tube 7 is
It is made of austenitic stainless steel, has a thin hexagonal shape, and accommodates many fuel rods 6 therein. The handling head 8 is used for suspending the fuel assembly and loading the fuel assembly into the core or removing the fuel assembly from the core. The handling head 8 is attached to the upper end of the flapper tube 7. On the other hand, the entrance nozzle 9 at the lower end is for letting liquid metal sodium flow into the fuel assembly in order to transfer heat generated in the fuel rod 6 to the cooling system. When the fuel assembly is loaded on the core, the spacer pad 10 is made thick so that the adjacent fuel assemblies and the thin wrapper tubes 7 come into contact with each other and slide with each other so as not to be worn or damaged, and the protrusions are formed. It is provided at several places in the axial direction of the fuel assembly. Generally, a material having good corrosion resistance, friction resistance and abrasion resistance is coated on the surface of the spacer pad 10, and a sprayed layer of chrome carbide, hard chrome plating, or the like has hitherto been applied. . The surface temperature of the spacer pad 10 during the operation of the reactor is:
It is almost equal to the temperature of the coolant, which is about 550 ° C. Therefore, the spacer pad 10 is supported in contact with a spacer pad of another fuel assembly adjacent thereto for a long period of time and at a high temperature. Chromium carbide and hard chromium are materials that coexist well with liquid metal sodium.However, when used for a long time and at high temperature, these metal substrates come into direct contact with each other to fuse, adhere, or slip. It can form and wear and can be damaged. In order to eliminate the cause of this damage, a film may be formed on the sliding surface of the spacer pad 10 to prevent direct contact between the metal substrates.

The use environment of the spacer pad 10 is as follows.
Since it is always in high-temperature liquid metal Na, the sliding member shown in FIG. 1, that is, a material obtained by mixing an appropriate amount of chromium oxide mainly with chromium carbide is used as a raw material, and is sprayed onto the surface of stainless steel with a plasma or an explosion gun. It is preferable to use a coated one. By applying this sliding member to the pad portion of the fuel assembly wrapper tube, damage due to fusion, adhesion or sliding wear can be prevented, and a highly reliable fuel assembly can be provided.

FIG. 4 is a partial sectional view showing a second embodiment of the sliding member according to the present invention. The sliding member according to the present embodiment is a surface-modified one similar to that shown in FIG. 1, and includes a metal base 1 made of stainless steel and a chromium formed including pores 5 on the surface of the metal base 1. It is composed of a porous coating layer 2 made of carbide or a nickel-based alloy, and chromium oxide 11 which forms a surface layer of the coating layer 2 and is impregnated in pores. In addition, metal base 1
Between the coating layer 2 and the coating layer 2, there is interposed a work-affected layer 3, which is a part of the metal base 1 which has crystal grains refined by blasting at the time of coating.

In the method of manufacturing the sliding member of the second embodiment, the coating layer 2 is formed by spraying chromium carbide or a nickel-based alloy on the surface of the blasted metal substrate 1 with a plasma or an explosion gun. Form. This kind of coating layer usually has 5 to 9% of pores 5 penetrating from the surface to the metal substrate. In this manufacturing method, the coating layer 2 is impregnated with chromium oxide using the pores 5. Chromium oxide (Cr ₂ O ₃ ) made into a slurry by a solvent is applied to the surface of the coating layer 2 to impregnate the pores 5 and then heated to about 500 ° C. to evaporate the solvent. By repeating the application and heating several times, the pores 5 are completely filled with the impregnated chromium oxide 11.

When this sliding member is immersed in Na, the impregnated chromium oxide 11 is converted into NaCrO ₂ and held in the pores 5. Therefore, even if NaCrO ₂ is discharged from the sliding surface, since it is supplied from the pores 5 of the coating layer 2, there is no delay time required for converting the impregnated chromium oxide 11 to NaCrO ₂ , and once converted to NaCrO ₂ . Then, a stable lubricating effect can be exhibited over a long period.

FIG. 5 shows an example in which the sliding member of the second embodiment is applied to a latch mechanism and a dashpot in a control rod drive mechanism of a fast breeder reactor. The control rod drive mechanism
A guide tube 13 fixed to the reactor vessel 12 side, an upper drive portion 14 as a movable portion, an extension tube 15 of the upper drive portion,
It comprises a bellows 16, which is a shaft seal, a latch mechanism 17, a control rod 18 suspended by the latch mechanism, and a dashpot 19 for receiving a control rod falling when the reactor is stopped. During operation of the nuclear reactor, the extension pipe 15 is moved up and down to control the nuclear reaction, and the control rod 18 connected thereto is also moved up and down. If it becomes necessary to shut down the reactor for any reason, the control rod 18
The latch is released and inserted into the core. This control rod 1
A dash pot 19 is provided to reduce the impact force when the 8 is inserted. The control rod drive mechanism has many sliding parts.
8 and the claw 20, and the control rod 1
8 There is a possibility of fusion or adhesion, wear and galling between the lower part of the control rod and the dash pot at the time of insertion. If fusion occurs in the latch mechanism 17, the control rod 18 cannot be inserted, and if galling occurs in the dashpot 19, the control rod 18 may not be able to be pulled out.
A nickel-based surface hardening material was coated. However, since all of these parts are used in Na, the metal may come into contact with each other or slip, causing friction and wear. Since these sliding parts require a fast movement, the sliding member of the second embodiment of the present invention is suitable. N
co immersed in a - in the coating layer, impregnated chromium oxide all NaCrO ₂ converts. For this reason, even if the reactor moves quickly when the reactor is stopped, NaCr
O ₂ is supplied, and a lubricating effect can be exhibited. Second embodiment of the present invention
By applying the sliding member of the embodiment to the latch mechanism and the dash pot portion in the control rod drive mechanism, it is possible to prevent fusion or adhesion, abrasion and galling in the sliding portion, and to improve the reliability of the nuclear reactor. .

FIG. 6 is a view showing a sliding member according to a third embodiment of the present invention. The sliding member of the present embodiment is composed of a material excellent in coexistence with Na, for example, a porous metal 21 made of stainless steel and including voids, and chromium oxide 22 impregnated in the voids. This sliding member is suitable for use as a component to be attached and detached.

The method of manufacturing the sliding member according to the third embodiment is as follows. The porous metal 21 is formed into a predetermined shape by sintering or foaming stainless steel.
Then, as described above, slurry-like chromium oxide is applied, and heating and application are repeated several times to impregnate the voids with chromium oxide. The porous metal 21 can be easily manufactured using a conventional manufacturing method, and the chromium oxide can be easily filled by repeating heating and application several times as described above.

The advantage of using a porous metal is that in the case of a material whose surface has been modified by coating like the sliding members of the first and second embodiments, when the thickness of the coating is increased, the thermal shock characteristics are increased. However, there is a possibility that the coating layer may be cracked or peeled off from the metal base and fall off due to the influence of internal strain, but these limitations are resolved. Also,
Since the porosity of the porous metal can be freely changed, it is possible to form a lubricant according to the sliding conditions. further,
If the design conditions are met, it can be manufactured as a single product, and it can handle complicated shapes.

FIG. 7 shows an example in which the sliding member of the third embodiment is applied to a bearing of a mechanical Na pump of a fast breeder reactor. The bearing portion of the mechanical Na pump according to the present invention includes a shaft 23, a bearing 24, a bearing housing 25, and a bearing support plate 26. The shaft 23 transmits the rotation of the motor to the impeller and causes the liquid metal Na to flow. The bearing 24 supporting the shaft 23 is
The working member is formed into a predetermined shape and attached to the bearing housing 25. When this bearing is immersed in Na, the chromium oxide impregnated in the voids reacts with Na to generate NaCrO ₂ and acts as a lubricant, thereby preventing galling at the bearing and reducing the amount of wear. . Furthermore, since a static pressure bearing is used in the bearing of the conventional mechanical sodium pump, a gap of about 0.5 mm is provided between the shaft and the bearing, so that a large amount of Na leaks from the bearing. As a result, the pump main body becomes one of the causes of becoming long. By adopting the bearing composed of the sliding member of the present embodiment, the gap between the shaft and the bearing can be significantly reduced as compared with the conventional case.
There is also an effect that it can contribute to shortening.

In the above application example, the bearing portion of the mechanical sodium pump is taken up. However, if the shaft 23 is replaced by a heat transfer tube and the bearing portion is replaced by a heat transfer tube support portion, an intermediate heat exchanger or a fast breeder reactor can be used. It becomes a sliding member for the heat transfer tube support in the steam generator, and can exert exactly the same action.

[0038]

Since the present invention is configured as described above, the following effects can be obtained.

In the sliding member of the lubricant spontaneous formation type (hereinafter abbreviated as sliding member) of claim 1, a coating layer made of chromium carbide mixed with chromium oxide is formed on the surface of the substrate made of stainless steel material. Chromium oxide combines with Na in Na to spontaneously form a unique lubricant, NaCrO ₂ , on the surface of the sliding member, and even if the formed lubricant is discharged from the sliding surface, it remains inside the sliding member. Since the mixed chromium oxide appears on the surface and generates NaCrO ₂ , there is an effect that the lubricating action can be maintained for a long time.

In the sliding member according to the second aspect, the first aspect is as follows.
Although a nickel-based alloy is used in place of chromium carbide constituting the sliding member, the same effect as the sliding member according to the first aspect can be obtained.

According to the third aspect of the present invention, the sliding member is composed of a base made of a stainless metal material, a chromium carbide coating layer having pores formed on its surface, and chromium oxide impregnated in the pores. Chromium oxide combines with Na in Na to produce the lubricant NaCrO ₂ ,
The same effect as that by the sliding member of the first aspect is achieved.

According to the fourth aspect of the present invention, there is provided the sliding member.
Although a nickel-based alloy is used instead of chromium carbide constituting the sliding member, the same effect as that of the sliding member of claim 3 (the effect of the sliding member of claim 1) is achieved.

In the sliding member according to the fifth aspect, since the sliding member is composed of the base made of a stainless metal material having pores and the chromium oxide impregnated in the pores, the chromium oxide is combined with Na in Na and lubricated. Produces the agent NaCrO ₂ ,
The same effect as that by the sliding member of the first aspect is achieved.

In the sliding member according to the sixth aspect, the chromium oxide is combined with sodium in liquid sodium to form a sodium composite oxide (NaCrO ₂ ). Has the same effect.

A method of manufacturing a sliding member of the present invention (hereinafter abbreviated as a manufacturing method of a sliding member).
Forms a surface layer by coating (spraying) a mixed material of a chromium carbide powder or a nickel-based alloy powder and a chromium oxide powder on a surface of a substrate made of a stainless metal material, so that a lubricant NaCrO ₂ is spontaneously spiked in Na. It is suitable for manufacturing a sliding member having a function of forming a hole.

According to a ninth aspect of the present invention, in the method for manufacturing a sliding member, a surface layer is formed by spraying chromium carbide powder or nickel-based alloy powder on the surface of a stainless metal material, and then applying chromium oxide in a slurry state to the surface layer. of impregnated into the pores, since the firing, even NaCrO ₂ chromium oxide is spontaneously formed combine with Na is discharged from the sliding surface, the NaCrO ₂ that is stored in advance in the interior of the sliding member It is suitable for manufacturing a sliding member which can be continuously supplied and which can maintain a lubricating action even for sliding in a fast movement.

According to a tenth aspect of the present invention, in the method for manufacturing a sliding member, a slurry-like chromium oxide is applied to the surface of a sintered or foamed stainless metal material, impregnated into pores, and fired. Can be changed freely, so that a lubricant can be formed according to the sliding conditions. Furthermore, if the design conditions are met, it is possible to manufacture a single product, and it is possible to cope with complicated shapes. .

In addition to the effects described above, a long-term low coefficient of friction and low wear can be achieved, and galling and fusing can be prevented. The effect of greatly improving is also obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a sliding member manufactured by a thermal spraying method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example in which the sliding member according to the first embodiment of the present invention is applied to a fuel assembly.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a partial cross-sectional view of a sliding member in Na manufactured by a thermal spray-impregnation method according to a second embodiment of the present invention.

FIG. 5 is a view showing an example in which the sliding member according to the second embodiment of the present invention is applied to a control rod driving mechanism.

FIG. 6 is a partial sectional view of a sliding member in Na manufactured by a sintering / foaming-impregnation method according to a third embodiment of the present invention.

FIG. 7 shows a sliding member according to a third embodiment of the present invention,
It is a figure showing the example applied to the bearing part of the pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal base 2 Coating layer 3 Process-altered layer 4 Chromium oxide 5 Pores 10 Spacer pad 11 Impregnated chromium oxide layer 17 Latch mechanism part 18 Control rod 19 Dash pot part 20 Claw 21 Porous metal 22 Chromium oxide 23 Shaft 24 Bearing

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Yamagata 1168 Moriyama-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Energy Research Laboratory (72) Inventor Shigehiro Shimoyashiki 1168 Moriyama-machi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Energy In the laboratory (58) Field surveyed (Int. Cl. ⁶ , DB name) C23C 26/00

Claims (10)

(57) [Claims] 1. A sliding member used in a sodium environment, comprising: a base made of a stainless metal material; and a coating layer formed on a surface of the base and made of chromium carbide mixed with chromium oxide. A lubricant spontaneously forming type sliding member. 2. A sliding member for use in a sodium environment, comprising: a base made of a stainless metal material; and a coating layer formed on a surface of the base and made of a nickel-based alloy mixed with chromium oxide. A sliding member that is spontaneously formed with a lubricant. 3. A sliding member used in a sodium environment, wherein a base made of a stainless metal material, a porous coating layer made of chromium carbide having pores formed on the surface of the base, A lubricant spontaneously forming type sliding member comprising chromium oxide impregnated therein. 4. A sliding member for use in a sodium environment, comprising: a base made of a stainless metal material; a porous coating layer made of a nickel-based alloy having pores formed on the surface of the base; A spontaneous lubricant forming sliding member comprising chromium oxide impregnated in pores. 5. A sliding member for spontaneously forming a lubricant, comprising: a sliding member used in a sodium environment, comprising: a base made of a stainless metal material having pores; and chromium oxide impregnated in the pores. Moving member. 6. A chromium oxide is combined with sodium in liquid sodium to form a sodium composite oxide (NaCrO).
The lubricant spontaneously forming type sliding member according to any one of claims 1 to 6, wherein ₂ ) is generated. 7. A method of manufacturing a sliding member used in a sodium environment, comprising coating a surface of a substrate made of a stainless metal material with a mixed material of chromium carbide powder or nickel-based alloy powder and chromium oxide powder. A method for producing a lubricant spontaneously forming type sliding member, characterized by forming a surface layer by heating. 8. The method according to claim 7, wherein the coating is formed by thermal spraying. 9. A method of manufacturing a sliding member for use in a sodium environment, wherein a chromium carbide powder or a nickel-based alloy powder is sprayed on a surface of a substrate made of a stainless metal material to form a surface layer having pores. Then, a slurry of chromium oxide is applied to the surface layer to impregnate the pores,
A method for producing a lubricant spontaneously forming type sliding member, characterized by firing. 10. A method for producing a sliding member used in a sodium environment, comprising applying a slurry-like chromium oxide to the surface of a sintered or foamed stainless metal material, impregnating the pores, and firing. A method for producing a lubricant spontaneous formation type sliding member, characterized in that: