JPH01254367A - Surface modified part and its manufacture - Google Patents

Abstract

PURPOSE:To improve the wear resistance and toughness of a part by forming a complex dispersing ceramics particles on a metal on the surface layer of the part for a pump, etc., and constituting the inner part of the part by a metal. CONSTITUTION:The mixture adding a binder to a ceramics particle is formed by filling it in the gap between dies 3a, 3b and a dry hardened layer 4 is formed. The dry hardened layer 4 is then set inside a ceramics mold 5, a molten metal 8 is poured from the upper part and the molten metal 8 is infiltrated among ceramics particles sucking it by reducing the pressure from the lower part. The wax pattern 11A contg. this complex 9 is made, a molten metal 14 is cast with the heating and pressure reducing suction of the complex 9 inside a mold 13 and a part mold 15 is obtd. The metallic complex 9 dispersing the ceramics particles on the surface layer is formed and the casting 15 filled with a metal at the part inner part is improved on the surface layer part at its wear resistance and the toughness is improved by the core part metal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a surface-modified component and a method for manufacturing the same, and in particular to a surface-modified component and a method for manufacturing the same, which are suitable for pump impellers and casings that require wear resistance. It relates to its manufacturing method.

[Conventional technology]

For example, in order to improve the wear resistance of pump parts, there is a method of making the parts material itself wear-resistant (
1st method), a method of applying a wear-resistant coating to the surface of the part (2nd method), a method of hardening by applying heat treatment such as quenching only to the surface (3rd method), composite material of metal and ceramic particles For example, there is a method of making parts using a method (fourth method).

As belonging to the first method, for example, high Cruj iron in the case of cast iron, high M n ! in the case of cast steel! Examples include 8 steel (Hutfield steel). The latter is aimed at surface hardening through work hardening.

Both methods involve adding alloying elements to improve wear resistance, which improves the hardness of the entire part.

Examples of methods belonging to the second method include hard chrome plating on the surface of parts, electroless Ni plating with dispersed ceramic particles, and ceramic spraying.

As belonging to the third method, there are methods of hardening the metal surface by utilizing the martensitic transformation of iron, such as surface hardening, carburizing, or nitriding hardening by high frequency heating, plasma heating, etc.

As a method belonging to the fourth method, there is a method in which fine ceramic particles are mixed with metal powder, molded, and then sintered.

An example of a tool belonging to the fourth method is a cemented carbide tool made by sintering alumina and iron powder using a binder.

Incidentally, as an example of this kind, for example, Japanese Patent Application Laid-open No. 60-216
No. 968, JP-A-60-223655, JP-A-62-
127158, JP-A-59-147769, and JP-A-56-66369.

[Problem to be solved by the invention]

The above-mentioned method has problems in preventing wear caused by sand and the like in pump parts, particularly dredging pumps, seawater pumps, sewage pumps, etc.

That is, the first method of making one entire part wear resistant is the Vickers hardness (hereinafter abbreviated as rHvJ) of at most 5oo (Hv5oo).

On the other hand, silica sand has an Hv of 4700 to 800, so it is inferior in terms of hardness.

Furthermore, since not only the surface layer but also the inner surface is hardened in this method, even if the wear resistance is good, the impact resistance of the two parts as a whole is reduced.

This is because, in general, the harder a material becomes, the more brittle it becomes.

Therefore, this method requires abrasion resistance for the surface layer, and is not suitable for applications requiring toughness for the entire component, and also increases costs because the entire component is of high quality.

The second method of applying a coating such as wear-resistant plating or ceramic spraying to the surface of a component has the following problems. The key to thermal spraying is to achieve uniform thickness.

The thickness of plating is relatively uniform, and the thickness uniformity of electroless plating is particularly excellent. And for both hard chrome plating and "composite plating", the hardness of the film itself is the former) (v90
0, the latter is Hv 1300, and ordinary steel is Hv 200
The hardness of the film is 5 to 7 times higher than that of 300, and the abrasion resistance of the film is excellent.

However, it is fine as long as these thin films (generally 50 μm or less for plating and 500 μm or less for thermal spraying) can withstand wear, but if the conditions are more severe and the film disappears, the Abrasion damage to the substrate increases rapidly, and eventually the part no longer serves its purpose.

For example, when the above plating (20 μm) was applied to a cast iron surface and a mixture of water and sand was sprayed at high speed onto the test surface, all the plating was worn off in about 0.5 minutes.

The third method, which involves surface heat treatment, causes problems such as the shape and dimensions of the product being distorted and cracks occurring due to heating. Therefore, machining is required again after that.

Especially when the material is cast iron, this method is rarely used because cracks occur in the product due to expansion of graphite.

The fourth method, in which fine ceramic particles are mixed with metal powder, molded, and sintered, increases the hardness of the entire part in the same way as in the first dimension.

In other words, this method increases the hardness of not only the surface layer but also the inner surface, so the wear resistance is good, but on the other hand, this tends to lead to a decrease in the wear resistance of the entire part.
Since the overall quality is high, the cost will increase significantly, so
This method requires abrasion resistance in the surface layer and is not suitable for applications that require toughness of the part as a whole.

There is also a method of casting ceramics, but this method is limited to pipe-like shapes and requires the metal to be placed on the outside, so it can only be applied to extremely limited applications.

There is also a method of casting parts containing special components with dissimilar metals or metals of the same type. However, this method requires a preheating step for the parts to ensure sufficient bonding between the molten base metal and the cast member. Furthermore, a mold into which this member is inserted has drawbacks such as difficulty in achieving dimensional accuracy and the manufacturing process being complicated.

An object of the present invention is to provide a method for manufacturing a surface-modified component that can sufficiently bond a base material and a cast member without requiring a special preheating step.

Another object of the present invention is to obtain a surface-modified component with excellent wear resistance and toughness as a component for a submersible pump that handles fluids containing highly hard particles such as earth and sand.

[Means to solve the problem]

The present invention is characterized by integrally molding a wax model for a mold and a casting material, embedding this in a mold, and then heating the casting material to eliminate the wax model, and at the same time molding the casting material. The method of manufacturing a surface-modified part includes heating the casting material to a temperature higher than the melting point of the metal, then casting the molten metal, thereby melting and adhering the high-temperature-heated casting material and the molten metal.

Another feature of the present invention is that the core material and the cast material are integrally molded, this is embedded in a mold, and then the core material is heated to eliminate the core material, and at the same time the cast material is The present invention provides a method for manufacturing a surface-modified part, in which a molten metal is cast while heated to a high temperature, thereby melting and adhering the molten metal to a casting material that has been heated to a high temperature.

Still another feature of the present invention is that the wax model for the mold and the casting material are integrally molded, the sprue of the model is brought into contact with the solid casting metal and embedded in the mold, and then the wax model is heated by high frequency induction. The casting material and the cast metal are heated, the wax model is vanished and removed by the heat, and the solid casting metal is melted and cast into the mold cavity formed at the same time, and the solid casting material and the heated casting material are melted. A method of manufacturing a surface-modified part by melting and adhering it to a cast metal.

Still another feature of the present invention is that a composite made by infiltrating molten metal into the interparticle gaps of a molded body of ceramic particles is installed at a predetermined location on the inner wall of the mold cavity, and the temperature of the composite is adjusted to the temperature of the cast metal. The method of manufacturing a surface-modified component includes heating the metal to a temperature above the melting point and then casting the molten metal into a mold cavity formed between the composite and the mold.

Another feature of the present invention is that the surface layer of a pump component that directly contacts a liquid containing high-hardness particles is a high-hardness member, the interior of the component is a metal, and the boundary between the surface-high-hardness member and the metal is Part is a surface-modified part for a pump that is a composite layer of the high-hardness member and the metal.

Still another feature of the present invention is that in a pump that handles fluid containing earth and sand, the surface layer of the pump parts that come into direct contact with the fluid is made of high manganese cast iron or high manganese cast steel 5US304.
．． The surface-modified part for a pump is made of high Cr cast iron, and the inside of the part is made of a metal such as cast steel, which has excellent WFI impact resistance and high tensile strength.

Another feature of the present invention is that the surface layer of a pump component that comes into direct contact with a fluid containing highly hard particles is made of a composite material in which ceramic particles are dispersed in metal, and the interior of the component is made of metal. It's in the parts.

[Effect]

In the above method for manufacturing a surface-modified component of the present invention.

In products such as wax models that use parts that disappear when heated as the core material, both the core material disappears and the cast parts are heated during the heating process to destroy the core material or the heating process of the cast parts. can be performed simultaneously using the same heating device. In other words, the heat applied to eliminate the core material can also be used to heat the cast members.
A special heating process and heating device for heating the cast member become unnecessary.

In addition, the surface-modified parts of the present invention have a high hardness on the surface layer and excellent toughness on the inside, so if this is used as a pump part that comes into direct contact with a fluid containing high-hardness particles, it can be used as a pump part. can significantly improve the lifespan and strength of

Furthermore, according to the manufacturing method of the present invention, not only the above-mentioned excellent surface-modified parts can be obtained.

Since the molten metal is cast while the temperature of the composite or cast member forming the surface layer is heated to a temperature higher than the melting point of the cast metal, the metal in the composite also melts and becomes integrated with the molten cast metal. In addition, in the case of cast parts, by making the joining surface of the cast parts into a complex shape such as a saw blade shape,
Since the viscosity of the molten metal is further reduced at the portion where it contacts the cast member, the molten metal can easily reach the complex joint surfaces of the cast member. Therefore, a surface-modified component in which a highly sophisticated surface member and a base metal having excellent toughness are firmly bonded can be obtained.

〔Example〕

First, to explain the basic structure of surface-modified parts, the surface layer of metal parts that require wear resistance is shown in Figure 1 (a).
) has a structure like this.

In other words, the thickness of the surface layer, for example 5 mm from the surface (this thickness varies depending on the case), is SiC or Bs.
It is a composite of high hardness ceramic particles such as C and AQz08 and metal as a base, and the other part is a metal layer. When the base metal 1 is steel and the high-hardness particles 2 are SiC particles, when hard particles such as earth and sand collide with the composite layer of steel 1 and SiC particles 2 (Fig. 1 (a)), the earth and sand generally harden. Since the steel (Hv 200-300) 1 is softer than SiC, it wears selectively, and the tops of the highly hard SiC particles 2 protrude (Fig. 1). b)).

Next, the earth and sand collide only with the protruding SiC particles 2,
It has Hv″F2600 and is 9 to 13 times harder than the base metal, so it hardly wears out.

This principle significantly improves the wear resistance of pump parts where necessary. Moreover, since this component is made of metal (steel), it does not exhibit the brittleness that is common with all-ceramic products, and can be used with confidence even in high-speed rotating objects.

Therefore, the durability of one part is greatly improved.

Next, the entire process of manufacturing the above-mentioned surface-modified component will be explained with reference to FIG.

(1) A mixture obtained by adding a binder (an inorganic binder such as colloidal silica) to ceramic particles such as SiC particles is hardened and molded in the gap formed by the molds 3a and 3b to form a dry hardened layer 4 (second figure(
,)).

(2) Next, the dry hardened layer 4 is set in the ceramic spinning mold 5 previously formed in the metal frame 5a, and molten metal 8 (molten steel) is poured from above.

At this time, vacuum suction is applied from the vacuum box 7 through the filter 6 provided at the bottom of the mold 5, and the molten steel 8 is infiltrated into the gaps between the SiC particles (Fig. 2 (a)). Remove outside. This creates a composite 9 of SiC particles and steel.

(3) Next, this composite 9 is made of a female mold 1 made of Si rubber.
0 (Fig. 2(c)).

(4) Furthermore, molten wax 11 is injected from the upper part of the sprue,
A wax model containing the complex 9 at the required locations is made (FIG. 2(c)).

Wax is a good model material. After injecting molten wax into the cavity of the Si rubber mold 10 in which the insert material is embedded, the Si rubber mold 10 is removed after waiting for the wax to solidify. As a result, the wax integrated model 11A (Fig. 2(d)
) can be obtained.

(5) Next, install this model 11A in the frame 12.

Fill the surrounding area with mold material (Fig. 2(d)).

(6) The wax is melted by heating and removed from the mold 13. A mold cavity containing the composite 9 is thus formed.

(7) The composite body 9 is heated by placing the &I type 13 in a high-temperature atmosphere, and the molten steel 14 is poured from the upper part of the sprue while vacuum suction is applied from the lower part of the mold (Fig. 2 (e)).
The composite body 9 and the molten metal are fused together to obtain an integrated casting 15 (
As shown in FIG. 2(f)), any material such as ai-containing metal Fs, AQ, Cu, or an alloy thereof may be used.

In the above embodiment, the dry hardened layer 4 includes, in addition to SiC particles, particles having higher hardness than the base metal, such as Anz○89-B4C or industrial diamond.

particles) is fine. The approximate hardness of these particles is
AQzOs is Hv first 1000~1300°SiC is Hv
42600. B4C has an Hv of 44,000 degrees, and diamond has an Hv of 8,000.

In addition, a composite is one in which the gaps formed in a molded body of particles 2 are impregnated with molten metal, and the particles 2 are mixed with an inorganic binder (colloidal silica, etc.), and this is inserted into a predetermined cavity by a mold. After that, molten metal was injected into the gaps between the particles. Note that the binder is determined in relation to the melting point of the cast metal. In other words, any binder that does not lose its cohesive strength at the melting point of the cast metal may be used. A high melting point binder such as colloidal silica is preferable, but ethyl silicate or water glass can also be used sometimes. For example, if the cast metal is Sn, An organic binder such as furan resin may be used, but it is desirable that the binder can exhibit binding strength even in a small amount.

The mold material 13 may be made of any aggregate or binder as long as it can cast molten metal and withstand the temperature when heating the composite enclosed in the cavity. Specifically, inorganic molds such as COz molds have a wide range of applications, but organic molds such as furan molds can also be cast iron, and the molds do not necessarily have to be integral molds.

Furthermore, in the case of atmospheric heating, it is desirable that the facing wall be as thin as possible.

Atmospheric heating is a common method for heating the mold.

However, high-frequency induction heating heats up quickly.

It can be heated.

Next, a specific example of the present invention will be described.

(Example 1) As shown in FIG. 3, 10 was separately molded on the inner wall of the cavity of the two-part inorganic self-hardening mold 16 by the method shown in FIG.
Composite 1 of SiC particles with 0 mesh beak and steel
7 was installed.

Next, this mold 16 was set in metal frames 18 and 19, and hot air at 600°C was blown through the opening 19a in the center of the upper metal frame 19 to heat the SiC particle layer to about 500°C.

After sono, 1400℃ cast iron T! ? 2 o of hot water was injected from the top of the mold 16.

When the mold 16 was removed after the molten metal 20 had solidified, a part was obtained in which a composite layer of cast iron of SiC particles was formed 0 to 5 m below the surface of the casting.

(Example 2) As shown in Figure 4, the multi-segment mold 21 (300 ash
iron powder: 100 parts by weight, 3 aquifer glass = 6 parts by weight of CO
S of 150 ash on the inner wall of z mold) with a thickness of 4 m + s.
A composite body 22 of iC particles and brass is installed.

This composite 22 has 150maghS i C particles=1
00 parts by weight, 10% PVA (polyvinyl alcohol)
This is a composite of a dried homogeneous mixture of 7 parts by weight of an aqueous solution and brass.

A high frequency coil 23 is installed outside the mold 21, and the iron powder mold 21 is heated by induction to about 800° C. using high frequency.
By transmitting the heat to the SiC composite 22, the composite 22 is brought to the same temperature.

Next, the metal frame 24 is installed on the upper part of the mold 21, and the molten brass metal 25 is poured from the sprue. Immediately thereafter, pressurized air of 3 atmospheres is applied to the scene, so that the molten metal 25 and the composite 2
2 and are in close contact and integrated.

After solidifying the molten metal 25, the mold was demolded to obtain a brass component having a wear-resistant layer on the surface.

The surface-modified part obtained in the example of FIG. 4 is an inducer used in a submersible pump, and an example of application of this inducer to a submersible pump will be explained with reference to FIGS. 5 to 8.

In the figure, 26 is a casing, 27 is a casing 26
28 is a suction port, 29 is an inducer that rotates together with the impeller 27 in the suction port 28,
This is what was obtained in the example shown in FIG. 30 is a pressure relief valve, this pressure relief valve 30 is connected to both sides of the inducer,
When the pressure difference between the inlet and outlet of the inducer 29 exceeds a predetermined level, the inducer 29 is opened to return the fluid to the upstream end of the inducer 29.

The applied part of the surface-modified parts of the present invention is indu.

- In addition to the sensor 29, this embodiment also applies to the impeller 27 and the casing 26. That is, Figures 6 to 8
As shown in the figure, each pump part (impeller 27,
Inducer 29. Surface modified layer 27 on casing 26)
a, 29a, and 26a are formed, respectively. In addition,
The modified layer of the above-mentioned surface-modified parts is made of SiC particles and has a thickness of 100
1:1 mixed grain of sh and 300 ash and cast steel (545C
), and the thickness of the layer is approximately 2I1ml.
It is as follows.

Furthermore, the base material of the surface-modified component is cast steel.

When a submersible pump constructed with such surface-modified parts was used for fluids containing particles such as earth and sand, the wear resistance of the pump parts was extremely good, and since the inside was made of metal, toughness was also improved. It was good.

As described above, the surface-modified component of the present invention has excellent wear resistance and toughness as a component for a submersible pump that handles fluids containing highly hard particles such as earth and sand.

Next, another example of the surface-modified component of the present invention will be described.

In the above embodiments, the surface modified layer was composed of high hardness particles such as ceramics, but in the following example, a member with a dissimilar acid portion (for example, high Mn steel) is cast on the surface of a base metal such as cast steel. The two are bonded together to form a hard layer with a thickness of approximately 511!1. Even if this is the case, it can be applied to pump parts in the same way as in the above embodiment. When hard particles such as earth and sand collide with the high Mn steel on the surface of the part, the high Mn steel receives stress. Since it is work hardened, it hardly wears out, and since the base metal is cast steel or other metal, it has excellent N impact resistance and tensile strength. Furthermore, in this example, only the surface has a high M.
Since it is an n-steel, it does not exhibit the difficult workability characteristic of high-Mn steels.

The members constituting the surface layer include high Mn fJ iron, high Mn cast steel, and 5US304. High Cr (25%) cast iron is suitable for wear resistance. In particular, 5US304 has excellent corrosion resistance.

In manufacturing the above-mentioned surface-modified parts, it is necessary to process the bonding surface of the rounded member 31 (the member forming the surface layer) into an uneven portion 31a as shown in FIG. Moreover, as shown in FIG. 10, it is more preferable to form a through hole 31b in the uneven portion 31a.

The cast metal (base metal) may be any cast steel or molten cast iron.

The type of mold is determined by considering the heating temperature of the casting material and the melting point of the cast metal.

The general method for heating the mold is to set the entire mold in a furnace and heat it in an atmosphere, but it is also possible to locally heat the mold using a hot air generator or the like immediately before casting.

Particularly effective is an electromagnetic induction heating method using high frequency, medium frequency, etc., which can heat at the highest temperature. However, in this case, heating is not possible unless it is a ferrous metal.

(If you install a material such as iron that conducts an induced current near the surrounding material or the solid cast metal buried in the mold, it will heat even if it is not a ferrous metal.) Next, according to Figure 11, , a method for manufacturing the above-mentioned surface-modified component will be explained.

First, as shown in Figure (a), a cast member 32 of 5O3304@ is prepared. This is placed in a split mold having a cavity of a predetermined shape, and polyethylene glycol (#4000) (hereinafter abbreviated as PEG) is injected into the cavity and solidified, and a cast member 32 is formed as shown in FIG. PEG3
Create a model 33 that combines 7.

Next, as shown in the figure, molding sand 3 is placed around the model 33.
6th step to fill 4 and make mold 35.

(d) As shown in the figure, when the high-frequency induction coil 36 is energized and the cast member 32 is gradually heated, the PE037 melts due to the heat and vaporizes at about 250°C, creating a cavity in the mold 35. It is formed.

Thereafter, current is passed through the coil 36 to heat the member 32 to near its melting point. After being heated to near the melting point, as shown in FIG. As a result, the lower part of the member 32 reacts with the molten metal 38 and melts into each other, so that a predetermined part of the common steel surface and the 5US304 member 32 are completely integrated (Figure (f)). By removing S[l53
A surface-modified part in which the cast member 32 made of 04 and the base metal 38a are firmly integrated is obtained. This part has excellent wear and corrosion resistance.

Another example of the method for manufacturing the surface-modified component of the present invention will be explained with reference to FIG.

(1) A separately molded cast member 39 made of high Mn steel is fitted into a two-part mold (female mold) 40 at the required location, and molten wax 41 is injected from the upper part of the sprue ((a)
)figure). As a result, a wax model 42 as shown in Figure (b) is obtained.

(2) Next, the wax model 42 is placed in the frame and the surrounding area is filled with molding material (molding sand) 44 to create the mold 43 (
(C) Figure).

(3) Next, as shown in figure (d), the high frequency coil 45 installed outside the mold 43 is energized to
By generating an induced current in 9, the temperature of 1 member 39 is raised, and at the same time, wax 41 is melted and removed from mold 43. As a result.

A mold cavity containing the cast member 39 is obtained.

(4) Immediately thereafter, the mold 43 is reversed, heating by the coil 45 is continued, and when the temperature of the cast member 39 rises to about 1200° C., ordinary steel 46 is poured (see Figure (e)).

(5)! ? By removing the mold material 44 when the copper-conducting steel 46 solidifies, a common steel casting (in this example, An inducer (as a pump component) was obtained.

Next, still another example of the method of manufacturing a surface-modified component according to the present invention will be explained with reference to FIG.

(1) Separately molded high Cr cast iron members 47 are installed at required locations in the two-part mold 40, and then PE0
48 is injected to create a wax model 49 including a cast member 47 at the bottom (Figures (a) and (b)).

(2) Next, install this in the frame and surround it with mold material 44.
Fill it. Note that when filling the mold material 44, the cast metal (
A block 50 of cast iron (Fe12) is installed so as to be in contact with the sprue at one end, and the surrounding area is also filled with mold material 44 to form a mold 51 (Figure (C)).

(3) By energizing the medium frequency coil 52 installed outside the mold 3 and generating an induced current in the member 47 and the metal block 50, the temperature of the member 47 and the metal block 50 is raised, and this heat melts the PEG 48. It is removed outside the mold 51 to form a mold cavity (Figure (d)).

(4) Thereafter, the mold 51 is reversed, and a current is further applied to the coil 52 to continue heating the metal block 50 until it reaches a molten state and is heated to the appropriate casting temperature. Next, by slightly tilting the mold 51. , molten metal 50 is placed in the cavity of the mold 51.
Cast a. At this time, the temperature of the first member 47 increases (approximately 100
0°C), they melt together with the molten metal and form a metallic bond (Figure (e)).

(5) As a result, as shown in Fig. (f), a normal cast iron part (inducer for a pump) in which high Cr cast iron (25% Cr) 47 with high wear resistance is cast is obtained.

The surface-modified parts obtained by the manufacturing method shown in FIGS. 11 to 13 can be used as parts for submersible pumps in exactly the same way as the embodiments shown in FIGS. 5 to 8. In this case as well, the same effects as in the case of FIGS. 5 to 8 can be obtained.

〔Effect of the invention〕

According to the present invention, the surface layer has special wear resistance due to high hardness or work hardening, and the inside is a surface modified ordinary cast steel product (ordinary cast iron product) having special surface characteristics, such as ordinary cast steel (cast iron). These surface-modified parts have excellent wear resistance and toughness, and are especially excellent as parts for pumps that handle fluids containing highly hard particles such as earth and sand. be.

Further, according to the method for manufacturing surface-modified parts of the present invention, not only can surface-modified parts excellent for use in pumps be obtained, but also
Molten metal is cast while the temperature of the composite that forms the surface layer is heated to above the melting point of the cast metal, resulting in surface modification that creates a strong bond between the highly sophisticated surface material and the base metal with excellent toughness. This has the effect that parts can be obtained.

Furthermore, in the present invention, in the manufacturing method using a wax model, the cast member is heated at the same time as the heating process to eliminate the wax model, so a special heating device or heating process is required for heating the cast member. The effect is that it is unnecessary.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the process of using the surface-modified component of the present invention, FIG. 2 is a diagram illustrating the manufacturing process of the surface-modified component of the present invention,
FIG. 3 is a diagram illustrating a specific example of the manufacturing method of the present invention, and FIG.
Figure 5 is a diagram illustrating another specific example of the manufacturing method of the present invention.
The figure is a longitudinal cross-sectional view showing an example of applying the surface-modified component of the present invention to a pump component, FIG. 6 is a cross-sectional view of an impeller seen in the direction of arrow VI-VI in FIG. The figure is an enlarged view of part A of Fig. 5, Fig. 8 is an enlarged view of part B of Fig. 5, and Figs. 9 and 10.
Each figure is an enlarged cross-sectional view of a main part of a facing member of a surface-modified part according to another example of the present invention, and FIGS. It is an explanatory view showing each side. 1... Steel, 2... High hardness particles, 8... Molten metal, 9°22... Composite, 11A... Wax model,
29...Inducer, 26a, 27a, 29a...
-Surface modified layer, 31, 32, 39, 47...casting member. 50...Solid cast metal. Agent Patent Attorney Katsuo Ogawa
7 -,,-7 1st cause (CL) 2 Sac @ issue Meiha derogashi 2 fig. 1. The 7th Kudzu of Tokit 8. Mouth 4 Sorrow 3. Clothes I! ffct'w4 $9 Mouth 3/ @<'SλwP Street 1/ε (Genjo 1) 2 l! 1

Claims (1)

[Claims] 1. The surface layer of a component for a submersible pump that handles fluid containing highly hard particles is a composite of metal and ceramic particles dispersed therein, and the interior of the component is made of metal. Surface modified parts. 2. A surface-modified part for a pump, which is in direct contact with a liquid containing high-hardness particles, and the surface layer thereof is made of a composite material in which ceramic particles are dispersed in metal, and the interior of the part is made of metal. . 3. A composite body made by infiltrating molten metal into the interparticle gaps of a molded body of ceramic particles is installed at a predetermined location on the inner wall of the mold cavity, and the temperature of the composite body is set to be equal to or higher than the melting point of the cast metal;
A method for manufacturing a surface-modified component, which comprises subsequently casting molten metal into a mold cavity formed between the composite and the mold. 4. The surface layer of the pump component that comes into direct contact with liquid containing high-hardness particles is a high-hardness member, the interior of the component is metal, and the boundary between the high-hardness surface member and the metal is the high-hardness member. A surface-modified part for a pump, characterized in that it is a composite layer of and the metal. 5. The surface-modified component for a pump according to claim 4, wherein the composite layer is configured such that the component ratio of the plurality of members forming the composite layer gradually changes as one approaches the other member. 6. The surface modification component for a pump according to claim 4, wherein the pump component that comes into direct contact with the liquid containing high-hardness particles is an inducer provided upstream of the impeller. 7. The wax model for the mold and the casting material are integrally molded, and this is embedded in the mold.The wax model is then heated to make the wax model disappear, and at the same time, the casting material is heated to the melting point of the cast metal. A method for manufacturing a surface-modified part, which comprises heating to the above temperature, then casting a molten metal, thereby melting and adhering the high-temperature-heated casting material and the molten metal. 8. In pumps that handle fluids containing earth and sand, the surface layer of pump parts that come into direct contact with the fluid is made of high manganese cast iron,
A surface-modified part for a pump, characterized in that the part is made of high manganese cast steel, SUS304, or high Cr cast iron, and the inside of the part is made of a metal with excellent impact resistance and high tensile strength. 9. The wax model for the mold and the casting material are integrally molded, the sprue part of the model is brought into contact with the solid casting metal, and the casting material is embedded in the mold, and then the casting material and the casting material are heated by high-frequency induction heating. is heated, the wax model is vanished and removed by the heat, and at the same time, the solid casting metal is melted and cast into the mold cavity formed, and the high-temperature heated casting material and molten casting metal are heated. A method for manufacturing surface-modified parts, characterized by melting and adhering them. 10. Molding the core material and the casting material integrally, embedding this in a mold, then heating the said casting material to eliminate the core material, and at the same time heating the casting material to a high temperature. A method for manufacturing a surface-modified part, characterized by pouring molten metal and thereby melting and adhering the molten metal to a casting material that has been heated to a high temperature.