JP6551766B2 - Laminated member, and impeller, compressor and engine using the same - Google Patents

Description

  The present invention relates to a laminated member, and an impeller, a compressor and an engine using the same.

  For example, as shown in Patent Document 1, there is a low pressure exhaust gas recirculation (EGR: Exhaust Gas Recirculation) system for reducing NOx in exhaust gas in a marine engine. This low pressure EGR system is to return to the supercharger inlet as a partial recirculating gas of the low pressure exhaust gas discharged from the supercharger outlet of the main machine to the exhaust pipe. As a result, the oxygen concentration of the combustion gas is reduced, and the rate of combustion, which is the reaction between the fuel and oxygen, is delayed, and the combustion temperature is reduced, whereby the amount of NOx generated can be reduced.

  Further, since a fuel having a large amount of S component is used for a marine engine, the exhaust gas contains an S component and a Cl component which are corrosive components of the impeller of the compressor of the turbocharger. Therefore, the EGR system is provided with a scrubber that removes the S component in the recirculation gas with washing water.

Patent No. 5916772 gazette Patent No. 5883001

  However, the S component may remain in the recirculation gas even when the recirculation gas is washed with a scrubber. Also, although the droplets contained in the recycled gas after cleaning are removed in the demister unit disposed downstream of the scrubber, the water in the recycled gas that has passed through the demister unit is sent to the compressor of the turbocharger. It may condense before reaching it.

  The droplets condensed in the recycle gas have a hydrogen ion concentration (pH) of about 1 to 2 due to the inclusion of the S component and the Cl component. Here, although a lightweight and high-strength Al alloy base material is used for the impeller of the compressor of the turbocharger, the Al alloy base material is corroded by the droplets contained in the recycle gas (corrosion May occur).

  Droplets condensed in the recycle gas impinge on the impeller of the compressor. As a result, the impeller may be plastically deformed and may be worn away (erosion may occur) due to repetition thereof.

  As a first countermeasure against the above problems, a method of anodizing the aluminum alloy base of the impeller may be considered, but this method may not be able to obtain sufficient erosion resistance and corrosion resistance. .

  Further, as a second countermeasure against the above-mentioned problems, a method of coating a ceramic layer by physical vapor deposition or chemical vapor deposition on the surface of the Al alloy base of the impeller can be considered. This ceramic layer becomes a high hardness film having corrosion resistance. However, in this method, when a droplet collides with the ceramic layer, the impact is transmitted to the inner Al alloy base material, and the Al alloy base material is deformed to generate a crack in the ceramic layer, resulting in the ceramic layer And the Al alloy base may peel off. In addition, the droplets may permeate the Al alloy substrate from the cracked or peeled portion and corrode the Al alloy substrate. In addition, defects may be present in the ceramic layer from the beginning (at the time of coating deposition), and the droplets may penetrate the Al alloy substrate from the defects and corrode the Al alloy substrate.

  Furthermore, as a third measure against the above problems, a method is conceivable in which electroless plating of a Ni-P alloy or the like is performed on the surface of the Al alloy substrate of the impeller. Therefore, corrosion resistance may not be obtained sufficiently.

  In view of the above technical problems, it is an object of the present invention to provide a laminated member combining erosion resistance and corrosion resistance, and an impeller, a compressor and an engine using the same.

A laminated member according to a first aspect of the invention for solving the above-mentioned problems is:
Al alloy base material,
An electroless plating layer formed on the surface of the Al alloy base material;
A Cr layer formed on the surface of the electroless plating layer,
A Cr-containing ceramic layer formed on the surface of the Cr layer;
And a polymer electrodeposition layer formed on the surface of the ceramic layer.

A laminated member according to a second invention for solving the above-mentioned problems is
In the laminated member according to the first aspect of the invention,
The electroless plating layer is harder than the Al alloy base material, and the Cr layer has an intermediate hardness between the ceramic layer and the electroless plating layer.

An impeller according to a third aspect of the present invention for solving the above-mentioned problems is:
It is characterized in that it is formed by the laminated member according to the first or second invention.

A compressor according to a fourth aspect of the present invention for solving the above-mentioned problems is:
The impeller according to the third aspect of the invention;
And a compressor casing that houses the impeller therein.

An engine according to a fifth aspect of the present invention for solving the above-mentioned problems is:
With the engine body,
The compressor according to the fourth aspect of the invention connected to the air supply side of the engine body, and a turbocharger having a turbine connected to the compressor and connected to the exhaust side of the engine body;
It is characterized by comprising an EGR system connected between an exhaust side of the turbine and an air supply side of the compressor.

  According to the laminated member according to the present invention, and the impeller, the compressor, and the engine using the same, both erosion resistance and corrosion resistance can be provided.

It is a schematic diagram explaining an engine and a compressor concerning the present invention. It is a schematic cross section explaining the lamination member concerning a reference example 1 of the present invention. It is a schematic cross section explaining the lamination member concerning a reference example 2 of the present invention. It is a typical sectional view explaining the lamination member concerning Example 1 of the present invention. It is a schematic cross section explaining the lamination member concerning Example 2 of the present invention.

  FIG. 1 is a schematic view illustrating an engine and a compressor according to the present invention. As shown in FIG. 1, an engine (marine engine 10) according to the present invention includes an engine body 11, a supercharger 12, an air cooler (cooler) 13, and an EGR system 14.

  The engine main body 11 is, for example, a uniflow sweep exhaust type diesel engine, and is a two-stroke diesel engine, and the sweep exhaust flow in the cylinder 11a is one direction from the lower side to the upper side so as to eliminate residual exhaust. It is The engine body 11 uses a fuel having a large amount of S component. The engine main body 11 supplies the combustion gas in the scavenging air trunk 11b to the cylinder 11a, burns it with the fuel in the cylinder 11a, and discharges the exhaust gas generated by the combustion from the cylinder 11a to the exhaust manifold 11c. The scavenging air trunk 11b of the engine main body 11 of the present invention is connected to the air supply pipe G1, and the exhaust manifold 11c is connected to the exhaust pipe G2.

  The supercharger 12 is connected via a rotation shaft so that the compressor (compressor 21) connected to the scavenging air trunk 11b of the engine body 11 and the turbine 22 connected to the exhaust manifold 11c of the engine body 11 rotate integrally. And are connected. In the turbocharger 12, the exhaust gas flowing in from the exhaust pipe G2 connected to the engine body 11 rotates the turbine 22. The rotation of the turbine 22 is transmitted, and the compressor 21 rotates. As the compressor 21 rotates, the combustion gas is compressed, and the compressed combustion gas is supplied to the engine body 11 through the supply air pipe G1.

  The compressor 21 includes a compressor casing (not shown) and an impeller (not shown). The compressor casing guides the combustion gas compressed by the compressor to the impeller, and guides the compressed combustion gas to the air supply pipe G1. The impeller is provided inside the compressor casing and is configured to be rotatable about the rotation axis. The impeller is formed of an environment-resistant member, which will be described later, based on an Al alloy (for example, JIS A2618). A silencer 21 a is further connected to the inlet side of the compressor 21 for the combustion gas.

  The silencer 21a is a cylindrical device provided with a plurality of silencer elements (not shown) in the circumferential direction. The silencer is configured so that noise generated by driving the compressor 21 does not escape to the engine room in which the engine body 11 is disposed. Furthermore, the silencer 21a forms a passage for introducing the combustion gas to the compressor 21. Here, the silencer 21a is provided with a path for guiding the air of the engine room from the silencer elements to the compressor 21 as combustion air, and an exhaust gas recirculation pipe G6 for introducing the recirculation gas to the compressor 21 from the axial direction of the silencer 21a. It is connected. During EGR operation, combustion gas is generated by mixing the recirculation gas from the exhaust gas recirculation pipe G6 and the combustion air.

  The turbine 22 is connected to an exhaust pipe G3 for discharging an exhaust gas generated by rotating the turbine 22. The exhaust pipe G3 is connected to a chimney (funnel) via an exhaust gas processing device (not shown).

  The air cooler 13 cools the combustion gas by exchanging heat between the combustion gas compressed by the compressor 21 and having a high temperature, and the cooling water, and raises the oxygen density in the combustion gas.

  The EGR system 14 includes exhaust gas recirculation pipes G4, G5, G6, a scrubber 23, a demister unit 24, and an EGR blower 25, and is connected between the exhaust side of the turbine 22 and the air supply side of the compressor 21 There is. The EGR system 14 recirculates a part of the exhaust gas discharged from the engine body 11 and passed through the turbine 22 to the engine body 11 as a recirculation gas. After the harmful substances are removed, the recycle gas is mixed with the combustion air, and is then compressed by the compressor 21 and recirculated to the engine body 11 as a combustion gas.

  The scrubber 23 removes harmful substances such as contained SOx (S component) and particulates (PM) such as dust by injecting a liquid to the recycle gas. Further, the scrubber 23 is connected to an exhaust gas recirculation pipe G5 that discharges the recycle gas and the drainage from which harmful substances have been removed.

  The demister unit 24 separates the recirculated gas from which harmful substances have been removed from the drainage liquid, and removes droplets in the recirculated gas. Further, the demister unit 24 is provided with a drainage circulation pipe W1 for circulating the drainage to the scrubber 23. The drainage circulation pipe W1 is provided with a hold tank 31 for temporarily storing drainage and a pump 32.

  The EGR blower 25 guides the recirculation gas from the scrubber 23 to the demister unit 24 from the exhaust gas recirculation pipe G5.

  In the engine according to the present invention, the laminated member according to the present invention, which combines erosion resistance and corrosion resistance, is used for the impeller of the compressor 21.

The engine according to the present invention is not limited to a marine engine, and is applicable to all engines having a low pressure EGR system.
Hereinafter, the lamination member according to the present invention will be described in each example and reference example with reference to the drawings.

[Reference Example 1]
FIG. 2 is a schematic cross-sectional view for explaining a laminated member according to the present embodiment. As shown in FIG. 2, the laminated member according to the present embodiment includes an Al alloy base material 41 and an electroless plating layer 42 formed on surfaces of the Al alloy base material 41 (upper side in the drawing, the same applies hereinafter). A Si layer 43 formed on the surface of the layer 42 and a diamond like carbon (DLC) layer 44 formed on the surface of the Si layer 43 are provided.

  The electroless plating layer 42 uses, as a specific example, electroless Ni-P plating or electroless Ni-B plating, or electroless Ni-P plating or electroless Ni-B plating composited with SiC or other hard particles. . In addition, by combining SiC and other hard particles with electroless plating, the hardness is increased and deformation is more difficult.

  In addition, the electroless plating layer 42 is plated with the S component reduced. This is realized by using a plating solution using a stabilizer having a low S component and a surfactant in the step of forming the plating.

  The laminated member which concerns on this reference example can be equipped with erosion resistance and corrosion resistance by having said structure. That is, by forming the electroless plating layer 42 and the DLC layer 44 on the surface of the Al alloy base 41, it is possible to prevent the occurrence of cracking due to the collision of droplets. That is, by providing the hard DLC layer 44, erosion resistance and corrosion resistance can be ensured.

  Further, the electroless plating layer 42 can improve the corrosion resistance of the electroless plating layer 42 itself by reducing the S component. The electroless plating layer 42 is not limited to the material, and a non-crystalline film of Ni-P or Ni-B compound can be applied.

  Furthermore, by providing the Si layer 43 between the DLC layer 44 and the electroless plating layer 42, the layered member according to the present reference example has reached the penetration defect (the surface of the Al alloy base 41) at the time of coating film formation. Corrosion) can be prevented.

  Further, if the electroless plating layer 42 is not provided, even if the DLC layer 44 has erosion resistance, the Al alloy base material 41 on the inner side (lower side in the figure, the same applies hereinafter) is deformed at the time of droplet collision. As a result, the DLC layer 44 is deformed and causes a crack. Therefore, in the present embodiment, the electroless plating layer 42 harder than the Al alloy base material 41 is provided between the Al alloy base material 41 and the DLC layer 44 to suppress the deformation of the DLC layer 44 in the upper layer. And the occurrence of cracking can be prevented. That is, although the DLC layer 44 has a small effect of preventing the occurrence of a crack in a single layer, the occurrence of the crack can be prevented by forming the electroless plating layer 42 on the inner side.

  Then, by providing the Si layer 43 between the DLC layer 44 and the electroless plating layer 42, the adhesion to the electroless plating is ensured (Si having an intermediate hardness between the DLC layer 44 and the electroless plating layer 42) Adhesion is improved by the layer 43) and penetration defects of the DLC layer 44 can be prevented.

  Since the DLC layer 44 is formed by a chemical vapor deposition method using a Si-based gas, the Si layer 43 is used as a layer provided between the DLC layer 44 and the electroless plating layer 42 as described above. The adhesion to the electroless plating layer 42 can be enhanced. In this respect, in Patent Document 2 described above, since it is an intermediate layer of a compound containing Si in carbon, the adhesion to the plating layer can not be improved as compared with this reference example.

  More specifically, the reason for using the Si layer 43 on the surface of the electroless plating layer 42 is that the intermediate hardness of the plating layer 42 and the DLC layer 44 is provided to the surface layer. The hardness is gradually increased to prevent peeling at the interface of each layer. Compared with the Si-containing carbon compound layer of Patent Document 2 described above, this configuration makes it possible to increase the hardness equally, to increase the response to deformation against impact force at the time of droplet collision, and between layers. The ability to prevent peeling will be increased.

[Reference Example 2]
FIG. 3 is a schematic cross-sectional view for explaining the laminated member according to the present embodiment. As shown in FIG. 3, as a laminated member according to the present embodiment, an Al alloy substrate 41, an electroless plating layer 42 formed on the surface of the Al alloy substrate 41, and an electroless plating layer 42 are formed. And a DLC layer 44 formed on the surface of the Si layer 43, and a polymer electrodeposited layer 61 formed on the surface of the DLC layer 44.

  That is, in the laminated member according to the present reference example, the polymer electrodeposited layer 61 is formed on the surface of the DLC layer 44 which is the outermost surface portion of the laminated member according to the reference example 1.

  As a specific example of the polymer electrodeposition layer 61, an epoxy, polyimide, fluorine or polyimide amide material is used. The thickness of the polymer electrodeposition layer 61 is 5 μm or more. This is because if the thickness is less than 5 μm, defects may occur. More preferably, it is 10-40 micrometers. In addition, since it is an electrodeposition layer, the upper limit in manufacture is about 50 micrometers.

  Furthermore, the surface of the DLC layer 44 is subjected to shot blasting with fine particles or a shot with media containing hard ceramic particles in viscoelastic particles. By forming the polymer electrodeposited layer 61 thereon, the adhesion between the polymer electrodeposited layer 61 and the DLC layer 44 can be improved.

  The polymer electrodeposition layer 61 thus provided has a role of relaxing the impact force of the droplets and a role of improving the corrosion resistance. Furthermore, corrosion due to penetration defects during coating film formation can be prevented more reliably.

Example 1
FIG. 4 is a schematic cross-sectional view for explaining the laminated member according to the present embodiment. As shown in FIG. 4, the laminate member according to the present embodiment is formed on the surfaces of an Al alloy base 41, an electroless plating layer 42 formed on the surface of the Al alloy base 41, and an electroless plating layer 42. A corrosion resistant metal layer 53 and a ceramic layer 54 formed on the surface of the corrosion resistant metal layer 53 are provided.

  The electroless plating layer 42 uses, as a specific example, electroless Ni-P plating or electroless Ni-B plating, or electroless Ni-P plating or electroless Ni-B plating composited with SiC or other hard particles. . In addition, the electroless plating layer 42 is plated with the S component reduced. This is realized by using a plating solution using a stabilizer having a low S component and a surfactant in the step of forming the plating. These points are the same as in the first embodiment.

  Further, the ceramic layer 54 is specifically a nitride or carbonitride such as CrN, TiN, TiCN or TiAlN. As a specific example of the corrosion resistant metal layer 53, Cr is used when the ceramic layer 54 contains Cr, and Ti is used when the ceramic layer 54 contains Ti.

  The laminated member which concerns on a present Example can be equipped with erosion resistance and corrosion resistance by having said structure. That is, by forming the electroless plating layer 42 and the ceramic layer 54 on the surface of the Al alloy base 41, it is possible to prevent the occurrence of cracking due to the collision of droplets. That is, by providing the hard ceramic layer 54, it is possible to improve the erosion resistance and the corrosion resistance.

  Further, as in the first reference example, the electroless plating layer 42 can improve the corrosion resistance of the electroless plating layer 42 itself by reducing the S component.

  Furthermore, by providing the corrosion-resistant metal layer 53 between the ceramic layer 54 and the electroless plating layer 42, the laminated member according to the present embodiment can prevent corrosion due to a penetration defect at the time of coating film formation.

  In addition, if the electroless plating layer 42 is not provided, even if the ceramic layer 54 has erosion resistance, the inner Al alloy base material 41 is deformed at the time of droplet collision, so that the ceramic layer 54 is formed. Will be deformed and cause cracking. Therefore, in the present embodiment, by providing the electroless plating layer 42 harder than the Al alloy base 41 between the Al alloy base 41 and the ceramic layer 54, the deformation of the upper ceramic layer 54 is suppressed. And the occurrence of cracking can be prevented. That is, although the ceramic layer 54 has a small effect of preventing the occurrence of cracks in a single layer, the occurrence of the cracks can be prevented by forming the electroless plating layer 42 on the inner side.

  Then, by providing the corrosion resistant metal layer 53 between the ceramic layer 54 and the electroless plating layer 42, the adhesion with the electroless plating layer 42 is secured (an intermediate position between the ceramic layer 54 and the electroless plating layer 42). The adhesion is improved by the corrosion-resistant metal layer 53 having hardness), and penetration defects of the ceramic layer 54 can be prevented.

  The ceramic layer 54 is formed by physical vapor deposition. For example, when the ceramic layer 54 is CrN, the Cr plate is melted and deposited by arc discharge, and when the ceramic layer 54 is TiN, the Ti plate is melted and deposited by arc discharge. Therefore, as the corrosion-resistant metal layer 53 provided between the ceramic layer 54 and the electroless plating layer 42, Cr is used when the ceramic layer 54 contains Cr, and Ti is used when the ceramic layer 54 contains Ti. . Thereby, the electroless plating layer 42 and the ceramic layer 54 can be firmly maintained. In this regard, in Patent Document 2, since it is an intermediate layer of a compound containing Si in carbon, adhesion with the ceramic layer 54 cannot be mainly improved.

  More specifically, the reason for providing a Cr layer if the ceramic layer 54 is CrN and a Ti layer if the ceramic layer 54 is TiN on the surface of the electroless plating layer 42 is that the plated layer 42 and the ceramic are used. By providing a layer having an intermediate hardness of the respective hardnesses of the layers 54, the hardness is gradually increased toward the surface layer to prevent peeling at the interface of each layer. Compared with the Si-containing carbon compound of Patent Document 2 described above, this configuration makes it possible to increase the hardness equally, to increase the response to deformation against the impact force at the time of droplet collision, and to separate the layers. Preventive ability will be increased.

Example 2
FIG. 5 is a schematic cross-sectional view for explaining the laminated member according to the present example. As shown in FIG. 5, the laminated member according to the present embodiment is formed on the surfaces of the Al alloy base 41, the electroless plating layer 42 formed on the surface of the Al alloy base 41, and the electroless plating layer 42. A corrosion resistant metal layer 53, a ceramic layer 54 formed on the surface of the corrosion resistant metal layer 53, and a polymer electrodeposited layer 61 formed on the surface of the ceramic layer 54 are provided.

  That is, the polymer laminate layer 61 is formed on the surface of the ceramic layer 54 which is the outermost surface portion of the laminate member according to the first embodiment.

  As a specific example of the polymer electrodeposition layer 61, as in Reference Example 2, an epoxy, polyimide, fluorine, or polyimide amide material is used. The thickness of the polymer electrodeposition layer 61 is 5 μm or more, and more preferably 10 to 40 μm.

  Further, the surface of the ceramic layer 54 is shot with fine particles, or shot with media containing hard ceramic particles in viscoelastic particles. By forming the polymer electrodeposited layer 61 thereon, the adhesion between the polymer electrodeposited layer 61 and the ceramic layer 54 can be improved.

  The polymer electrodeposition layer 61 thus provided has a role of relaxing the impact force of the droplets and a role of improving the corrosion resistance. Furthermore, corrosion due to penetration defects during coating film formation can be prevented more reliably.

  The present invention is suitable as a laminated member, and an impeller, a compressor and an engine using the same.

10 Marine Engine 11 Engine Body 12 Turbocharger 13 Air Cooler 14 EGR System 21 Compressor 22 Turbine 23 Scrubber 24 Demister Unit 25 EGR Blower 31 Hold Tank 32 Pump 41 Al Alloy Base Material 42 Electroless Plating Layer 43 Si Layer 44 DLC Layer 53 Corrosion Resistance Metal layer 54 Ceramic layer 61 Electrodeposited layer of polymer

Claims (5)

Al alloy base material,
An electroless plating layer formed on the surface of the Al alloy base material;
A Cr layer formed on the surface of the electroless plating layer,
A Cr-containing ceramic layer formed on the surface of the Cr layer;
And a polymer electrodeposition layer formed on the surface of the ceramic layer. The electroless plating layer, the Al is harder than alloy substrate, and claim 1, wherein the Cr layer is characterized by having an intermediate hardness between the ceramic layer and the electroless plating layer The laminated member as described in. An impeller formed by the lamination member according to claim 1 or 2 . An impeller according to claim 3 ;
And a compressor casing for housing the impeller therein. With the engine body,
A compressor according to claim 4 , connected to the air supply side of the engine body, and a turbocharger having a turbine connected to the compressor and connected to the exhaust side of the engine body.
An engine comprising: an EGR system connected between an exhaust side of the turbine and an air supply side of the compressor.

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