JP2007327349A - Member for feed pump and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a member for a feed pump manufacturable at low cost and having hard film with excellent corrosion resistance and adhesiveness on a surface thereof, and a method for manufacturing the same. <P>SOLUTION: An impeller 1 is provided with a roughly bell shape cylindrical part and a blade part formed around the same. Partially enlarged section part 11 near a surface of the impeller 1 is provided with metal base material 12, and amorphous film 13 formed on a surface of the base material 12 by high frequency plasma CVD method. A thickness of the amorphous film is preferably 1-50μm. Hardness thereof is preferably HV 700-2800. An arithmetic mean roughness Ra of surface of the amorphous film is preferably 0.5μm or less and ten point average roughness Rz is preferably 2.0 or less. A ratio of hydrogen atoms in the amorphous film is preferably in a range of 10-50 atom%, the rest being composed of carbon atoms. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid feed pump member having excellent corrosion resistance and antifouling properties and a method for producing the same. In particular, the present invention relates to liquids handled by pumps having various types, structures and performances (for example, seawater, industrial water (cooling water), pure water, water and sewage water, acids, alkalis, organic solvents, chemical processes, and medical science). The present invention relates to a member for a feed pump used for feeding a chemical solution for use in petroleum, a petroleum-based liquid for petroleum refining and petrochemical processes, and a method for producing the same.

In general, liquid pumps can be roughly classified as follows when classified as hydraulic opportunities.
(1) Spiral pump (volute pump, turbine pump, propeller pump)
(2) Axial flow pump (movable blade propeller pump)
(3) Reciprocating pump (piston pump, plunger pump)
(4) Rotary pump (gear pump, vane pump)
(5) Special pump (friction pump, bubble pump, jet pump)

On the other hand, these pumps are variously named according to the type and purpose of liquid feeding, and are classified as follows according to the type of liquid feeding.
(1) Water and aqueous solutions (pure water, industrial water (for cooling), water and sewage water, seawater, acid, alkali)
(2) Various process liquids (inorganic and organic liquids in the chemical industry)
(3) Petroleum liquid (crude oil, refined oil, refined residue oil)
(4) Medical science, pharmaceutical fluids (physiological saline, synthetic drug solution, infusion, injection solution, etc.)
Since these liquid feeds have different physicochemical properties and have different liquid feed amounts and lifts, various types of pumps are applied.

  When looking at the corrosion damage of pump parts by type of liquid by material, cast iron, cast steel, various stainless steels, Ti and Ti alloys, etc. are applied according to each target, and various surface treatments are applied to the surface of these members A film is formed to improve corrosion resistance and cavitation erosion resistance. For example, the following Patent Documents 1 and 2 disclose a technique of thermal spray coating by Ni plating and WC cermet in order to prevent corrosion due to liquid feeding. Further, in Patent Document 3 below, fluorination passivation treatment technology, in Patent Document 4 below, a sprayed coating technology for anti-slurry erosion, and in Patent Document 5 below, Ni for preventing cavitation and erosion. Techniques such as base and Co base welding overlay are disclosed.

JP 2004-036555 A JP 2004-019490 A JP 2001-288555 A JP 2004-010974 A JP 2003-247084 A

  However, the current liquid feed pumps represented by Patent Documents 1 to 5 have the following problems in corrosion and corrosion prevention.

(1) Use of a high-grade corrosion-resistant material to suppress corrosion of the pump member due to liquid feeding increases the cost significantly and is not economical.

(2) Although the electroplating film and the thermal spray coating according to the prior art are improved in corrosion resistance and erosion resistance as compared with an untreated substrate, the performance is not sufficient. Further, the application of these surface treatment films is difficult depending on the shape of the pump member, and even if a film can be formed, the performance of the film is not sufficient, and the expected results are not obtained. Specifically, in electroplating, it is excessively stacked on the convex shape of the pump member, but it cannot be formed on a narrow portion. In addition, the thermal spraying method has the same effect as electroplating, and even when the thermal spray angle is 45 degrees or less, even if a film can be formed, the adhesion is low, and the intended purpose cannot be achieved.

(3) In a pump incorporating a member on which various surface treatment films are formed, the pump base material and the surface treatment film have different potentials. It can lead to corrosion damage (a phenomenon commonly called electric corrosion).

(4) Peeling of the coating is always a problem in pump members with various surface treatment coatings, and depending on the application, the following failures may occur due to the peeling coating.
(A) Degradation of pharmaceutical solution quality due to contamination of the peeled film.
(B) The pump operation is stopped due to the imbalance of the high-speed rotating impeller, rotor, etc. due to the peeling of the metal film having a large specific gravity.

(5) If a large amount of solid foreign matter (for example, pulp, oil sludge, etc.) is mixed in the liquid feeding, these foreign matter adheres to the rotating parts such as impellers and rotors that are pump members, preventing rotational movement. , Stable operation over a long period of time may not be possible.

(6) In a pump that uses pharmaceuticals and ultrapure water as a pump, there is a quality problem such that the product is significantly contaminated by a small amount of metal components eluted from the pump member.

  Therefore, the present invention provides a member for a liquid feed pump that can be manufactured at low cost and has a hard film having excellent corrosion resistance and adhesion on the surface, and a method for manufacturing the same.

  The member for a liquid feed pump of the present invention is obtained by coating an amorphous film mainly composed of carbon and hydrogen on the surface of a base material directly or through an undercoat film.

  In the liquid feed pump member of the present invention, it is preferable that the amorphous film has a thickness in the range of 1 μm to 50 μm.

  In the liquid feed pump member of the present invention, the hardness of the amorphous film is preferably in the range of HV700 to 2800.

  In the liquid feed pump member of the present invention, the arithmetic average roughness Ra of the surface of the amorphous film is preferably 0.5 μm or less and the ten-point average roughness Rz is preferably 2.0 μm or less.

  In the liquid feed pump member of the present invention, the amorphous film has a carbon atom ratio of 90 atomic% to 50 atomic% and a hydrogen atom ratio of 10 atomic% to 50 atomic%. In addition, the composition ratio of the carbon atoms and the hydrogen atoms to the amorphous film is preferably 100 atomic% or less.

  In the liquid feed pump member of the present invention, the base material is essentially composed of cast iron, cast steel, a simple substance of Ti, Al and alloys thereof, structural steel containing carbon and having chromium as an essential component, and Ni and Cr. One metal material selected from stainless steel and Ni-base alloy as components is preferable.

  In the liquid feed pump member of the present invention, the undercoat film has a thickness of 0.1 μm to 3 μm of one or more kinds selected from a simple substance of Ti, W, Nb, Ta, Cr, Al, Si or an alloy thereof. A membrane is preferred.

  In the liquid feed pump member of the present invention, one or more elements selected from C, Ti, W, Nb, Ta, Cr, Al, Si, or an alloy thereof are injected into the surface portion of the substrate. It is preferable to further have an injection layer formed by doing so.

  In the liquid feed pump member of the present invention, the arithmetic average roughness Ra of the surface of the substrate is preferably 2.0 μm or less, and the ten-point average roughness Rz is preferably 8.0 μm.

  In the method for producing a member for a liquid feed pump according to the present invention, the substrate surface processing is performed so that the arithmetic average roughness Ra of the substrate surface is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less. And an amorphous film coating step of coating and forming an amorphous film mainly composed of carbon and hydrogen on the base material.

  In the method for manufacturing a liquid feed pump member of the present invention, an injection layer of an element selected from C, Ti, W, Nb, Ta, Cr, Al, and Si is formed on the surface portion of the processed base material. It is preferable to have a step between the substrate surface processing step and the amorphous film coating step.

  As another aspect, the method for producing a member for a liquid feed pump according to the present invention is processed so that the arithmetic average roughness Ra of the surface of the substrate is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less. A base material surface processing step to be performed, and an undercoat film made of a simple substance selected from C, Ti, W, Nb, Ta, Cr, Al, and Si or an alloy thereof is formed on the surface of the processed base material. An undercoat film coating step, and an amorphous film coating step of coating an amorphous film mainly composed of carbon and hydrogen on the surface of the undercoat film.

  Since the amorphous film mainly composed of carbon and hydrogen formed on the liquid feed pump member of the present invention has a dense and chemically stable property, it is acid, alkali, inorganic and organic for various processes. Exhibits excellent corrosion resistance against liquids. Further, since the above-described amorphous film is a hard film, it is difficult to cause scratches even when it comes into contact with foreign substances contained in the liquid feeding. Furthermore, since this amorphous film has a relatively smooth surface, it can be expected to have an effect that it is difficult to adhere foreign substances. Therefore, the liquid pump member according to the present invention is expected to be used with confidence as a liquid medicine that avoids the contamination of a small amount of metal components and as a pump for ultrapure water. In addition to extending the operation period of the pump, repair costs It can be expected to greatly contribute to the improvement of industrial production and the reduction of production costs by reducing exchange costs.

  In addition, according to the method for producing a member for a liquid feed pump of the present invention, uniform film formation is possible even for a member for a liquid feed pump such as a rotor or casing having a complicated shape. In other words, it is possible to form uniform coatings on various liquid feed pump members having different shapes.

  Below, the impeller (one of the members for liquid feeding pumps) which concerns on embodiment of this invention, and its manufacturing method are demonstrated.

<First Embodiment>
FIG. 1 is a perspective view showing an impeller according to a first embodiment of the present invention. FIG. 2 is a partially enlarged sectional view of the vicinity of the surface of the impeller according to FIG.

  The impeller 1 includes a substantially bell-shaped cylindrical portion 1a and blade portions 1b, 1c, and 1d formed around the cylindrical portion 1a. The partially enlarged cross-sectional portion 11 near the surface of the impeller 1 includes a metal base 12 and an amorphous film 13 formed on the surface of the base 12.

Examples of the base material 12 include cast iron, cast steel, simple elements of Ti and Al and alloys thereof, structural steel containing carbon and containing chromium as an essential component, stainless steel and Ni-based alloy containing Ni and Cr as essential components, and the like. Can be mentioned. In particular, cast iron and cast steel contain a large amount of carbon, microscopically segregate into chrysanthemum, flakes, and spheres, and coexist with Fe ₃ C (cementite). Since it shows good adhesion, the amorphous film 13 can be formed in a dense state from a microstructural view. The arithmetic average roughness Ra of the surface of the substrate 12 is 2.0 μm or less, and the ten-point average roughness Rz is 8.0 μm.

  The amorphous film 13 is mainly composed of carbon and hydrogen, and has a thickness in the range of 1 μm to 50 μm. 5-20 micrometers is especially suitable. A film thinner than 1 μm does not have sufficient corrosion resistance and wear resistance, and a film thicker than 50 μm takes a long time to form a film. On the other hand, no significant improvement in film performance is observed, leading to an increase in production cost. It's not a good idea.

  The hardness of the amorphous film 13 is in the range of HV700 to 2800 in terms of micro Vickers hardness. Compared to the hardness of cast iron and cast steel (HV 130 to 200), it is extremely hard and exhibits excellent cavitation and erosion properties.

  Further, the amorphous film 13 is composed of carbon atoms in a range of 90 atomic% to 50 atomic%, hydrogen atoms in a range of 10 atomic% to 50 atomic%, and the amorphous film 13. The composition ratio of the carbon atom and the hydrogen atom with respect to is adjusted to be 100 atomic% or less. The amorphous film 13 preferably has a hydrogen content of 10 atomic% to 50 atomic% and the remainder is made of carbon. Furthermore, if the amorphous film 13 having a hydrogen content of 10 atomic% to 35 atomic% is used, most of the liquid feed pump member is less susceptible to large thermal expansion and mechanical deformation, and the artificial diamond film is formed. Although it is soft in comparison, the residual stress of the film generated at the time of film formation becomes small, so that the adhesion and ductility are further improved. Note that an amorphous film having a hydrogen content of less than 10 atomic% generates a large internal stress at the time of film formation, so that it is difficult to form a thick film (10 μm or more), and although it is hard, it has poor ductility. There is a tendency to peel off due to slight deformation of the substrate. On the other hand, if the hydrogen content is larger than 50 atomic%, the hardness and mechanical strength of the amorphous film 13 are lowered, which is not preferable.

  Further, the arithmetic average roughness Ra of the surface of the amorphous film 13 is 0.5 μm or less, and the ten-point average roughness Rz is 2.0 μm or less. Therefore, since it is a smooth surface, solid foreign substances are in a state where it is difficult to physically adhere.

  Such an amorphous film 13 is dense and is not corroded at all even when immersed in an aqueous solution of acid, alkali, etc., and has no pores, so that only the pores of the substrate are preferentially corroded. There is no occurrence of pitting corrosion. The amorphous film 13 formed on the surface of the substrate 12 is used at less than 400 ° C. This is because at 400 ° C. or higher, it may be decomposed into carbon dioxide or water. In addition, since the specific gravity is about 1.7 to 1.8, even if the above-described disassembly or separation occurs in the impeller 1 that rotates at high speed, the rotation hardly affects the rotation. The stable pump operation can be continued without breaking In addition, the amorphous surface mainly composed of carbon and hydrogen is usually oleophilic (hydrophobic). However, as a modification, N or Si is injected to change the surface to hydrophilic. The surface function can be controlled and used depending on the type.

  Next, the manufacturing method of the impeller 1 is demonstrated for every process.

(1: Finishing process of substrate surface)
On the surface of the base material 12 for forming the amorphous film 13, the arithmetic average roughness Ra is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less by mechanical, chemical and electrochemical methods. Finish to the state of. If such surface finishing is not performed, the surface of the base material 13 is rough, and thus projections and the like may exist. Therefore, when the thickness of the amorphous film 13 formed on the surface of the base material 12 is relatively thin as 10 μm, the amorphous film 13 in the portion where the protrusion is present may be destroyed at an early stage or may be a starting point of corrosion. There is.

  When mechanically polishing, the arithmetic average roughness Ra is set to about 1 to 3 μm using a fine-grained # 600 polishing belt, and then surface projections are removed by lapping or buffing to obtain a ten-point average roughness. The thickness Rz can be finished to 1.5 or less. In addition, if the surface after finishing the fine abrasive belt is subjected to a chemical polishing method (for example, a mixed solution of nitric acid, hydrochloric acid, phosphoric acid, etc.) or an electrolytic polishing method is applied in these polishing solutions using the substrate 12 as an anode, arithmetic A mirror surface having an average roughness Ra of 0.1 μm and a ten-point average roughness Rz of 0.5 μm or less is obtained, and a particularly suitable pretreatment surface can be formed. However, when the thickness of the amorphous film 13 is 10 μm to 50 μm, the amorphous film 13 having good adhesion and performance can be formed only by mechanical polishing (Ra is 1 μm to 3 μm, Rz is 4 μm to 8 μm). At the same time, the surface roughness of the amorphous film is not easily affected by the roughness of the base material and tends to be smoothed.

(2: Amorphous film formation process)
Next, the process of forming an amorphous film on the surface of the substrate 12 that has undergone the above-described finishing process will be described. FIG. 3 is a schematic configuration diagram of an apparatus for forming an amorphous film. This apparatus includes a grounded reaction vessel 2, an organic gas introduction device (not shown) for film formation and a reaction vessel connected to the internal space of the reaction vessel 2 via valves 7a and 7b, respectively. Via a lead device 9 for applying a high-frequency current to a vacuum device (not shown) for evacuation and a conductor 3 connected to a base material 12 of an impeller 1 disposed at a predetermined position in the reaction vessel 2. A high voltage pulse generating power source 4 for applying a high voltage pulse, a plasma generating power source 5 for applying a high frequency to the conductor 3 through the introduction terminal 9 and generating plasma around the base material 12 of the impeller 1, and a pulse In addition, in order to share the application of high frequency with one conductor 3, it is provided between the high voltage pulse generating power source 4 and the plasma generating power source 5, and is electrically connected to the high voltage introducing unit 9. Device 6 , And a ground wire 8 connected reaction vessel 2 and the surface electrical.

  In order to form the amorphous film 13 on the surface of the base material 12 using the apparatus having the above-described configuration, the base material 12 as an object to be processed is installed at a predetermined position, the vacuum apparatus is operated, and the valve 7b is used. After the air in the reaction vessel 2 is discharged, an organic hydrocarbon gas is introduced into the reaction vessel 2 through the valve 7a by a gas introduction device.

  Here, the kind of hydrocarbon gas which can be used in this embodiment is demonstrated. The types of gases introduced into the reaction vessel 2 are as follows, and are organic hydrocarbons composed of carbon and hydrogen and B, Si, O, Cl, etc. added thereto.

(1) Gas phase state at room temperature (18 ° C.) CH ₄ , CH ₂ CH ₂ , C ₂ H ₂ , CH ₃ CH ₂ CH ₃ , CH ₃ CH ₂ CH ₂ CH ₃
(2) Liquid phase at normal temperature C ₆ H ₅ CH ₃ , C ₆ H ₅ CH ₂ CH, C ₆ H ₄ (CH ₃ ) ₂ , CH ₃ (CH ₂ ) ₄ CH ₃ , C ₆ H ₁₂ , C ₆ H ₅ Cl
(3) Organic Si compound (liquid phase)
(C ₂ H ₅ O) ₄ Si, (CH ₃ O) ₄ Si, (CH ₃ ) ₄ Si, [(CH) ₃ Si] ₂ O
A compound in a gas phase at normal temperature can be introduced into the reaction vessel 2 as it is, but a compound in a liquid phase is heated to gasify it, and this vapor is supplied into the reaction vessel 2. In order to increase the carbon content in the amorphous film 13, the C / H ratio in the hydrocarbon gas is increased, and in the opposite case, by using a gas having a large hydrogen content, the C content of the amorphous film 13 is increased. The ratio of / H can be controlled. Note that when an amorphous film is formed using an organic Si compound, Si may be mixed into the film, but since Si is strongly bonded to carbon, it does not hinder the use in this embodiment. .

  After introducing the hydrocarbon gas into the reaction vessel 2 as described above, high frequency power from the plasma generating power source 5 is applied to the substrate 12. Since the reaction vessel 2 is in an electrically neutral state by the ground wire 8, the base material 12 has a relatively negative potential. For this reason, + ions in the plasma of the introduced gas generated by the application are characterized by being generated along the shape of the negatively charged substrate 12. Further, a high voltage pulse (negative high voltage pulse) from the high voltage pulse generation source 4 can be applied to the base material 12 to positively attract + ions in the plasma to the surface of the base material 12. By this operation, an amorphous film 13 having a uniform thickness can be formed on the surface of the substrate 12. In this plasma, the following phenomena (1) to (4) occur, and finally an amorphous film 13 mainly composed of carbon and hydrogen is formed on the surface of the substrate 12. thinking.

(1) Ionization of introduced gas (hydrocarbon) (active neutral particles called radicals also exist).
(2) The ions and radicals changed from the gas collide impactively with the surface of the substrate 12 to which a negative voltage is applied.
(3) C—H having a low binding energy is cut by an impact at the time of collision, and C and H are polymerized, including a polymerization reaction, accompanied by a sputtering phenomenon.
(4) An amorphous film 13 containing C and H is formed on the surface of the substrate 12.

  Note that it is possible to repeat the pulse with a pulse width of 1 μSec to 10 mSec and a pulse number of 1 to multiple times. Further, the output frequency of the high frequency power of the plasma generating power source 5 can be changed in the range of several tens of kHz to several GHz. The method of forming the amorphous film 13 with the above policy is referred to herein as a high frequency plasma CVD method.

  Here, the uniformity of the film thickness of the amorphous film formed by the apparatus having the configuration shown in FIG. 3 will be described.

  When hydrocarbon gas is excited by plasma, gas molecules are decomposed and activated, and finally an amorphous solid mainly composed of carbon and hydrogen is deposited. When a large amount of this solid matter is deposited, it eventually becomes a film and covers the surface of the substrate. However, the formation of an amorphous film formed by the action of only plasma energy has a different deposition amount depending on the atmospheric concentration of the hydrocarbon gas. Therefore, when forming an amorphous film on a member with a complicated shape, the concentration is equalized. Therefore, the thickness of the formed amorphous film is also uneven.

  On the other hand, in this embodiment, in order to eliminate the disadvantages of the film forming mechanism, the film to be processed is set to a relatively negative potential (the processing container is set as a positive potential), and electrochemical On the other hand, a high-frequency current was loaded on the substrate to be treated using this mechanism. When hydrocarbon gas is circulated in such a state, hydrocarbon gas molecules excited by the action of plasma dissociate into atoms and radicals, and each is charged to a positive ion, so that the negative potential is processed. It is attracted electrochemically to the surface of the substrate to deposit an amorphous solid. In this case, since it is not controlled by the concentration of the hydrocarbon gas by the conventional method, positive ions excited from the hydrocarbon gas can move to places having a negative potential even in an object having a complicated shape. Therefore, it is possible to form an amorphous film having a uniform thickness. In addition, a film can be formed on the inside of piping for joining to the pump. For example, the amorphous film 15 can be formed on the surface of the substrate 14 to be processed having an S shape or a T shape shown in FIG. In other words, the uniform amorphous film 15 can be formed even on the T-shaped substrate 14 having a large curved S-shape or right-angled portion, and the entire surface of the substrate 14 is corrosive. Can be protected from.

  Since the amorphous film 13 mainly composed of carbon and hydrogen formed on the surface of the impeller 1 of the present embodiment has a dense and chemically stable property, it is used for acids, alkalis, and various processes. Excellent corrosion resistance to inorganic and organic liquids. Further, since the amorphous film 13 is a hard film compared to the base material 12, it is difficult to cause scratches even if it comes into contact with foreign substances contained in the liquid feeding. Furthermore, since the amorphous film 13 has a relatively smooth surface, it can be expected to have an effect that it is difficult to attach foreign substances. Therefore, the impeller 1 of the present embodiment is expected to be used with confidence as a liquid medicine that avoids the contamination of a small amount of metal components and as a pump member for ultrapure water, and is repaired in addition to extending the operation period of the pump. It can be expected to greatly contribute to the improvement of industrial production and the reduction of production cost by reducing costs and replacement costs.

Second Embodiment
Next, an impeller according to a second embodiment of the present invention will be described. In addition, the part of the codes | symbols 11 and 13 of 1st Embodiment and the part of the codes | symbols 21 and 23 of this embodiment respond | correspond in order, The description may be abbreviate | omitted. FIG. 5 is a partially enlarged sectional view of the vicinity of the surface of the impeller according to the second embodiment of the present invention.

  Although the shape of the impeller of this embodiment is not shown, it is the same as the impeller 1 of the first embodiment. A partially enlarged cross-sectional portion 21 in the vicinity of the surface of the impeller of this embodiment includes a base material 22 and an amorphous film 23 formed on the surface of the base material 22.

  The base material 22 has the base material main part 22a and the injection layer 22b formed on the surface of the base material main part 22a (surface part of the base material 22). The injection layer 22 b is formed by injecting one or more elements selected from C, Ti, W, Nb, Ta, Cr, Al, and Si into the surface portion of the base material 22. As a modification, a metal thin film may be formed between the injection layer 22 b and the amorphous film 23.

  Next, a method for manufacturing the impeller according to the present embodiment will be described. In addition, since the finishing process of the base material 22 surface and the formation process of the amorphous film 23 are the same as those in the first embodiment, the description will be simplified, and the formation process of the injection layer 22b of the base material 22 will be described in detail.

  First, by using the apparatus of FIG. 3 described in the first embodiment, by changing the output voltage of the high voltage pulse generation source 4, ion implantation including metal is performed on the surface of the base material 22 for implantation. Layer 22b is formed. Then, an amorphous film 23 is formed on the surface of the injection layer 22b in the same manner as in the first embodiment.

In the modification described above, the apparatus shown in FIG. 3 can also be used when a metal thin film is formed between the injection layer 22 b and the amorphous film 23. For example, it can be used for forming each layer on the surface of the base material 22 or the surface under the following conditions (1) to (4).
(1) When ion implantation is focused on the surface of the base material 22: 10 to 40 kV
(2) When ion implantation and metal thin film formation are performed: 5 to 20 kV
(3) When forming a metal thin film on the substrate 22: several hundred V to several kV
(4) When metal thin film formation is focused on the base material 22 by sputtering or the like: several hundred V to several kV
Therefore, after forming a metal ion implantation or metal thin film having a strong chemical affinity with carbon such as Cr, Si, Ta, Nb, Ti on the surface or the surface of the base material 22, the amorphous film 23 is laminated thereon. It is possible.

  According to the above configuration, the same effect as that of the first embodiment is achieved, and the amorphous film 23 is formed on the base material 22 via the injection layer 22b. The adhesion of the amorphous film 23 is increased. Accordingly, it is possible to provide an impeller having an amorphous film 23 that is more difficult to break or peel off and a method for manufacturing the impeller.

<Third Embodiment>
Next, an impeller according to a third embodiment of the present invention will be described. In addition, the site | part of the codes | symbols 11-13 of 1st Embodiment and the site | parts of the codes | symbols 31-33 of this embodiment respond | correspond in order, The description may be abbreviate | omitted. FIG. 6 is a partially enlarged cross-sectional view of the vicinity of the surface of the impeller according to the third embodiment of the present invention.

  Although the shape of the impeller of this embodiment is not shown, it is the same as the impeller 1 of the first embodiment. In the impeller of this embodiment, a partially enlarged cross-sectional portion 31 near the surface includes a metal base 32, an undercoat 34 (undercoat film) formed on the surface of the base 32, and the surface of the undercoat 34. And an amorphous film 33 formed on the substrate.

  The undercoat 34 is a film having a film thickness of 0.1 to 3 μm of at least one selected from a simple substance of Ti, W, Nb, Ta, Cr, Al, and Si or an alloy thereof.

  Next, a method for manufacturing the impeller according to the present embodiment will be described. In addition, since the finishing process of the base material 32 surface and the formation process of the amorphous film 33 are the same as those in the first embodiment, the description will be simplified and the formation process of the undercoat 34 will be described in detail.

  First, the surface of the base material 32 is finished in the same manner as in the first embodiment, and the undercoat 34 is applied to the surface of the base material 32 using one or more methods selected from an electroplating method, a CVD method, and a PVD method. Form. Then, an amorphous film 33 is formed on the surface of the undercoat 34 in the same manner as in the first embodiment.

  According to the above configuration, the same effect as that of the first embodiment is achieved, and the amorphous film 33 is formed on the base material 32 via the undercoat 34. Therefore, the amorphous film 33 is simply formed on the surface of the base material 32. The adhesion of the amorphous film 33 is increased. Therefore, it is possible to provide an impeller having an amorphous film 33 that is more difficult to break or peel off, and a method for manufacturing the impeller.

  Hereinafter, the present invention will be specifically described with reference to examples.

Example 1
In this example, the hydrogen content of the amorphous film formed on the surface of the Al base material described below, the resistance to bending deformation of the base material, and the subsequent change in corrosion resistance were investigated.
-Base material and test piece Al (JIS H 4000 regulations 1085) was used as a base material, and from this, a test piece having dimensions: width 15 mm x length 70 mm x thickness 1.8 mm was prepared.
(2) Amorphous film formation method and its properties An amorphous film having a thickness of 1.5 μm was formed over the entire surface of the test piece. At this time, the hydrogen content in the amorphous film was 5 to 50 atomic%. What was controlled to the range of (the remainder is carbon) was formed.
(3) Test Method and Conditions The test piece on which the amorphous film was formed was bent at 90 °, deformed, and the appearance of the amorphous film at the bent portion was observed with a 20 × magnifier. Then, the above-mentioned test piece was exposed for 96 hours in the salt spray test of JIS Z 2371.
(4) Test results Table 1 below summarizes the above contents and test results. As is apparent from the results, when the amorphous film has a low hydrogen content and a high carbon content (No. 1, No. 2), when the bending deformation of 90 ° is applied, the amorphous film peels or Partially peeled off. When these peeling test pieces were used for salt spray test pieces, it was found that the base Al was corroded, a large amount of white rust was generated, and the corrosion resistance was completely lost. In contrast, the amorphous film having a hydrogen content of 10 atomic% to 50 atomic% (No. 3 to No. 8) does not peel off even by bending deformation, and withstands salt spray tests and maintains excellent corrosion resistance. It was confirmed that

(Example 2)
In this example, in order to investigate the basic anticorrosion performance of the amorphous film according to the present invention, SS400 steel and Al having a high versatility were used as a base material, and the amorphous film was shown in Table 2 below. Thus, the film thickness was directly formed in the range of 0.5 μm to 50 μm. Further, as a corrosive environment, the corrosion resistance was investigated by exposing to an atmosphere having different corrosion characteristics such as high humidity, salt spray, 5% H ₂ SO ₄ , and 5% NaOH.
(1) Base material and test piece As a base material, the test piece of width 30mm x length 50mm x thickness 2mm was produced from SS400 steel and Al (JIS H 4000 regulations No. 1070), respectively.
(2) Formation and Thickness of Amorphous Film Using the apparatus shown in FIG. 3, an amorphous film having a thickness ranging from 0.5 μm to 50 μm was prepared over the entire surface of the test piece.
(3) Corrosion test conditions The following conditions were selected as the corrosion test conditions.
(A) High humidity atmosphere: The test piece was exposed in an atmosphere of 30 ° C. and 90% relative humidity using a constant temperature and humidity chamber. (200h)
(B) Salt spray: A 96-h test was conducted by the salt spray test method specified in JIS Z 2371.
(C) 5% H ₂ SO ₄ immersion: It was immersed in a 5% H ₂ SO ₄ aqueous solution (20 to 25 ° C.) for 100 hours.
(D) 5% NaOH immersion: It was immersed in a 5% NaOH aqueous solution (30 to 35 ° C.) for 100 hours.
(4) Evaluation method The evaluation of the corrosion test results was carried out by visual observation of changes in the surface of the test piece before and after the test and changes in the color tone of the H ₂ SO ₄ and NaOH aqueous solutions. In addition, as a test piece for comparison, an untreated SS400 steel and Al were subjected to a corrosion test under the same conditions.
(5) Corrosion test results Table 2 below summarizes the above contents and test results. From this result, the untreated SS400 steel test piece generated red rust or dissolved (No. 5) in all test atmospheres (No. 1, 3, 5) except 5% NaCl immersion. Moreover, in the untreated test piece of Al (No. 2, 4, 6, 8), white rust was generated (No. 4) under conditions other than in a high humidity atmosphere, and acid (No. 6), alkali ( No. 8) also dissolved while generating hydrogen gas. On the other hand, the test piece in which the amorphous film was formed exhibited excellent corrosion resistance regardless of the type of the base material, and showed sufficient corrosion resistance in all corrosive environments when the film thickness was 1 μm or more. However, when the film thickness was 0.5 μm, the occurrence of red rust was suppressed in a high humidity atmosphere and immersion in an alkaline aqueous solution, but slight rust and white rust were observed in salt spray and sulfuric acid immersion. From the above results, it was found that the effective anticorrosive action of the amorphous film was observed in the range of 0.5 μm to 50 μm, and in particular, the range of 1 μm to 50 μm was suitable.

(Example 3)
In this example, in order to investigate the tightness of the amorphous film according to the present invention, a ferroxyl test defined in JIS H 8645 is performed as follows to check whether there are fine through-pores in the amorphous film. investigated.

(1) Base material It was set as the base material of FC200 (dimensions width 50mm x length 70mm x thickness 7mm).
(2) Formation and thickness of amorphous film As shown in Table 3 below, an amorphous film is applied to the entire surface of the base material to have a thickness in the range of 0.5 μm to 8 μm. Each specimen was formed.
(3) Test piece of other comparative example As another comparative example, Ni and Cr were respectively applied to the surface of the base material by electroplating using a test piece having the same dimensions as the base material manufactured from the FC200 base material. A test piece coated to a thickness of 15 μm and a test piece in which a 50 mass% Ni-50 mass% Cr alloy was formed to a thickness of 100 μm by a thermal spraying method were prepared.
(4) Feroxyl test method Specifically, the following method was used as the ferroxyl test. That is, 10 g of potassium hexacyanoferrate (III) and 15 g of sodium chloride are dissolved in 1 liter of distilled water, and this is sufficiently impregnated in a filter paper for analysis. Thereafter, the filter paper was affixed to the surface of the test piece and allowed to stand for 30 minutes, and then the filter paper was peeled off to visually determine the presence or absence of blue spots on the filter paper surface. This is because, when there are through pores in the amorphous membrane, the ferroxyl test solution penetrates, reaches the iron substrate interface and generates iron ions, and this reacts with potassium hexacyano (dish) acid, and blue on the surface of the filter paper. It can be determined by generating spots.
(5) Feroxyl test results Table 3 below summarizes the above contents and test results. As is apparent from the results, the amorphous films shown as comparative examples having a thin film thickness of 0.5 μm, 0.8 μm (No. 1, No. 2), Ni plating films (No. 6 to 8) In the Cr plating film (Nos. 9 to 11) and the sprayed coating specimens (Nos. 12 to 14), the occurrence of a few or many blue spots was observed. On the other hand, in the amorphous film according to the present invention (with a film thickness of 1.0 μm or more (No. 3 to 5)), no blue spots are observed, there are no through pores, and the tightness is improved. It has been confirmed that it is rich and has an excellent effect of preventing the intrusion of corrosive components.

Example 4
In this example, SS400 steel and SUS304 steel base materials were used, and prior to the formation of the amorphous film, the corrosion resistance when the ions of various elements were implanted into the base material surface and the influence of bending were investigated.
(1) Base material SS400 steel having a size of width 15 mm x length 60 mm x thickness 1.5 mm was used as a test base material.
(2) Ion Implantation Device, Kind of Implanted Ion Element and Amorphous Film Thickness As the ion implantation device, the high-frequency plasma CVD device disclosed in FIG. 1 was used. As the implanted ion element, atomic concentrations C, Ti, W, Nb, Ta, Cr, Al, and Si having an implanted ion concentration of 1 × 10 ¹⁴ to 1 × 10 ¹⁶ per 1 cm ² were used. The thickness of the amorphous film formed on the substrate was 10 μm.
(3) Test conditions The following tests (a) and (b) were performed on each test piece of this example.
(A) Immersion in 5% HC1 aqueous solution for 24 hours (20 ° C to 25 ° C)
(B) 96 hours immersion in a 10% NaOH aqueous solution (20 ° C. to 25 ° C.)
Further, in this example, the test piece after the corrosion test was bent at 90 °, and the presence or absence of the strips of the amorphous film in the bent portion was examined.
(4) Test piece of comparative example As a test piece of a comparative example, SS400 steel was used for the corrosion test in an untreated state.
(5) Corrosion test results Table 4 below summarizes the above contents and test results. As is clear from this result, the SS400 steel (No. 10) of the comparative example generated a large amount of red rust in the 5% HCl aqueous solution immersion test, and red rust that had already dropped off was also observed. However, almost no change was observed in the 10% NaOH immersion test (No. 9). In contrast, the test piece on which the amorphous film was formed was bent at 90 °, and the bent part was observed with a magnifying glass. As a result, no peeling of the amorphous film was observed in the ion-implanted test piece. However, in the test piece (No. 9) in which no ion implantation was performed, the amorphous film was slightly peeled off. From this result, it was found that the adhesion of the amorphous film was further improved by ion implantation of an element having a strong binding force with carbon as used in this example.

(Example 5)
In this example, prior to the formation of an amorphous film on the surface of SS400 copper and SUS304 steel substrate, the corrosion resistance when various metal thin films were formed and the adhesion of the film during bending of the substrate were investigated. .
(1) Base material SS400 steel having a width of 15 mm, a length of 60 mm, and a thickness of 1.5 mm was used as a base material.
(2) Thin film forming apparatus used in this example, thin film type, and amorphous film thickness As the thin film forming apparatus, the high frequency plasma CVD apparatus disclosed in FIG. 1 was used, and Ti, W, Nb, Ta, A thin film (thickness 2 μm) of any one of Cr, Al, and Si was formed on the surface of the base material, and an amorphous film having a thickness of 10 μm was formed thereon to obtain a test piece.
(3) Corrosion test condition It carried out on the same conditions as Example 4. However, in this example, the specimen after the corrosion test was bent by 90 °, and the presence or absence of the strips of the amorphous film in the bent portion was also investigated.
(4) Test piece of comparative example As a test of a comparative example, untreated SS400 steel was used.
(5) Corrosion test results Table 5 below summarizes the above contents and test results. As is apparent from the results, the comparative example SS400 steel (No. 9) has poor corrosion resistance. It was significantly corroded by a 5% HCl aqueous solution to generate a large amount of red rust, and rust loss was also observed. On the other hand, the test pieces (Nos. 1 to 8) on which the amorphous film was formed showed excellent corrosion resistance regardless of whether or not the metal thin film was applied. The test piece after the corrosion test was bent at 90 °, and the peeling state of the amorphous film in the bent portion was confirmed using a magnifying glass. As a result, the test piece without a thin film (No. 8) was slightly. Peeling of the amorphous film was observed, but none of the other specimens was observed at all. From the above, it was found that the undercoat thin film tested was effective in improving the adhesion of the amorphous film.

(Example 6)
This example is a comparative study of the effect of an impeller to which an amorphous film according to the present invention is applied to a high-speed rotary pump for high heads installed in a desulfurization apparatus of an oil refinery plant, together with an untreated member. is there.

Name of test pump: High-speed multistage centrifugal pump called commercially available sandine pump Test member name: Inducer, impeller (both are made of cast stainless steel SCS13)
Type of liquid feed: Thickness of heavy oil amorphous film containing sulfur compound and sludge: 20 μm

  When the above pump was used in an actual plant, all untreated impellers were subjected to the effects of cavitation and erosion during operation for about one week, causing erosion, changing the shape itself, and pump performance of 20 to 25 % And a large amount of sludge adhered. On the other hand, it was confirmed that the impeller formed with the amorphous film according to the present invention withstands the operation for 8 weeks and has very little sludge adhesion and maintains the pump performance for a long period of time. Even if the material of the impeller was changed to Ti or Ti alloy, the maximum operation time was about 2 weeks. The same result was obtained for a member for a liquid feed pump called an inducer.

  The present invention can be changed in design without departing from the scope of the claims, and is not limited to the above-described embodiments and examples. For example, in each of the above embodiments, an impeller has been shown. However, a similar film can be formed on the surface of a substrate also in other liquid feed pump members (for example, a rotor, a casing, etc.). A member can also be used as one member of a liquid feed pump. Moreover, in the base material 32 in 3rd Embodiment, the layer similar to the injection layer 22b in 2nd Embodiment may be formed in the contact surface side with the undercoat 34. FIG.

1 is a perspective view showing an impeller according to a first embodiment of the present invention. It is a partially expanded sectional view of the surface vicinity of the impeller of FIG. It is a schematic block diagram of the apparatus used in the manufacturing process of the impeller of FIG. It is the schematic diagram used in order to demonstrate the film thickness distribution situation at the time of forming an amorphous film | membrane with respect to the S-shaped and T-shaped base material by the method which concerns on 1st Embodiment of this invention. It is a partially expanded sectional view of the surface vicinity of the impeller which concerns on 2nd Embodiment of this invention. It is a partially expanded sectional view of the surface vicinity of the impeller which concerns on 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impeller 1a Cylinder part 1b, 1c, 1d Blade | wing part 2 Reaction container 3 Conductor 4 High voltage pulse generation source 5 Power supply for plasma generation 6 Double device 7a, 7b Valve 8 Ground wire 9 Introduction terminal 12, 14, 22, 32 groups Material 11, 21, 31 Partially enlarged portion (near the impeller surface) 13, 15, 23, 33 Amorphous film

Claims (12)

  A member for a liquid feed pump, characterized in that an amorphous film mainly composed of carbon and hydrogen is coated on the surface of a base material directly or through an undercoat film.   2. The liquid feed pump member according to claim 1, wherein a thickness of the amorphous film is in a range of 1 μm to 50 μm.   The liquid pump member according to claim 1 or 2, wherein the hardness of the amorphous film is in a range of HV700 to 2800.   4. The arithmetic average roughness Ra of the surface of the amorphous film is 0.5 μm or less, and the ten-point average roughness Rz is 2.0 μm or less. 5. Liquid feed pump member.   The amorphous film has a composition in which the ratio of carbon atoms is in the range of 90 atomic% to 50 atomic%, the ratio of hydrogen atoms is in the range of 10 atomic% to 50 atomic%, and the carbon atoms with respect to the amorphous film. And the composition ratio of this hydrogen atom is 100 atomic% or less, The member for liquid feeding pumps of any one of Claims 1-4 characterized by the above-mentioned.   The base material is cast iron, cast steel, simple substance of Ti, Al and alloys thereof, structural steel containing carbon and containing chromium as an essential component, and stainless steel and Ni-based alloy containing Ni and Cr as essential components The liquid feed pump member according to claim 1, wherein the liquid feed pump member is a metal material selected from the group consisting of:   The undercoat film is a film having a film thickness of 0.1 μm to 3 μm of at least one selected from a simple substance of Ti, W, Nb, Ta, Cr, Al, Si or an alloy thereof. The member for liquid feeding pumps of ~ 6.   It further has an injection layer formed by injecting one or more elements selected from simple substances of C, Ti, W, Nb, Ta, Cr, Al, and Si or alloys thereof into the surface portion of the substrate. The member for liquid feeding pumps of any one of Claims 1-7 characterized by the above-mentioned.   The liquid feed pump according to any one of claims 1 to 8, wherein an arithmetic average roughness Ra of the surface of the substrate is 2.0 µm or less, and a ten-point average roughness Rz is 8.0 µm. Materials. Substrate surface processing step for processing so that the arithmetic average roughness Ra of the surface of the substrate is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less,
A method for producing a member for a liquid feed pump, comprising: an amorphous film coating step of coating an amorphous film mainly composed of carbon and hydrogen on the base material.   The step of forming an injection layer of an element selected from C, Ti, W, Nb, Ta, Cr, Al, and Si on the surface portion of the processed base material includes the base material surface processing step and the amorphous film. The method for producing a member for a liquid feeding pump according to claim 10, wherein the method is provided between the coating step and the coating step. Substrate surface processing step for processing so that the arithmetic average roughness Ra of the surface of the substrate is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less,
An undercoat film coating step for coating an undercoat film made of a simple substance selected from C, Ti, W, Nb, Ta, Cr, Al, and Si or an alloy thereof on the surface of the processed base material;
A method for producing a liquid feed pump member, comprising: an amorphous film coating step of coating an amorphous film mainly composed of carbon and hydrogen on the surface of the undercoat film.

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