JPH0231219B2 - PISUTONRINGU - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an improved piston ring, and more particularly to a piston ring for internal combustion engines with improved composite dispersion plating adhesion and sliding characteristics. (Prior Art and Problems) In recent years, as internal combustion engines have become lighter and have higher output, the quality required of piston rings has become higher. Conventionally, piston rings for internal combustion engines have been subjected to wear-resistant surface treatments such as hard chrome plating, thermal spraying, or nitriding on the sliding surfaces as a means of improving their durability. Among these surface treatments, nitriding treatment in particular has been attracting attention as a surface treatment for piston rings used under severe operating conditions because it exhibits excellent wear resistance. However, while the nitrided layer has excellent wear resistance, it cannot necessarily be said to have sufficient seizure resistance compared to hard chrome plated layers or thermal sprayed layers, and abnormal wear may occur when used under harsh operating conditions. . Recently, composite dispersion plating in which hard particles are dispersed in a nickel-cobalt-phosphorous base, which has excellent wear resistance and seizure resistance, has been used. However, when a composite dispersion plating film containing phosphorus is applied to chrome steel, especially those with increased thickness and hardness for practical use, when used under harsh operating conditions,
It may peel off from the interface with the base material or cause abnormal wear, and improvements have been desired. (Purpose) In view of the above, the present invention has been made for the purpose of providing a piston ring for an internal combustion engine that exhibits good adhesion and sliding characteristics of the composite dispersion plated layer on the outer peripheral sliding surface even under severe usage conditions. It is something that (Means for Solving the Problems) In the present invention, as a piston ring that achieves the above object, as a first invention, a particle size of 0.2 to 10 μm is added to the outer peripheral sliding surface of the piston ring in a nickel matrix.
2 to 30% by volume of hard particles of metal nitride, metal carbide, or metal oxide dispersed in
It has a composite dispersed nickel strike plating layer with a thickness of 20 μm, and on top of that, a matrix of nickel alloy containing 10 to 50% by weight of cobalt and 2 to 10% by weight of phosphorus has grain size of 0.2 to 10 μm. 5 to 5 hard particles of metal nitride, metal carbide, or metal oxide
A piston ring for internal combustion engines having a composite dispersed nickel plating layer dispersed at 30% by volume.
As an invention, in a piston ring, 5 to 30 volumes of hard particles of metal nitride, metal carbide, or metal oxide with a particle size of 0.2 to 10 μm are contained in a nickel matrix on the outer peripheral sliding surface of the piston ring. It has a composite dispersed nickel strike plating layer with a thickness of 2 to 20 μm in which particles are dispersed in a nickel alloy base containing 10 to 50% by weight of cobalt and 2 to 10% by weight of phosphorus. A total of 5 hard particles of metal nitride, metal carbide, or metal oxide with a diameter of 0.2 to 10 μm and solid lubricant particles with a particle size of 0.2 to 10 μm
A piston ring for an internal combustion engine having a composite dispersed nickel plating layer dispersed in ~30% by volume. (Function) In the first invention, as shown in FIG. 1, a strike layer a of nickel plating that does not contain phosphorus is used to strengthen the adhesion between the base material and the composite dispersion plating.
to form. This nickel strike plating layer a is used to increase the seizure resistance of the strike plating layer.
A dispersed layer of hard particles having a particle size of 0.2 to 10 μm, preferably 0.5 to 5 μm is formed. Conventionally, a simple nickel plated strike has been used as a method to strengthen adhesion, but a simple nickel plated layer has poor seizure resistance and abrasion resistance, and although adhesion is sufficient, it cannot be used as a sliding surface. It was insufficient. When a nickel-cobalt-phosphorus composite dispersion plated layer is subjected to heat curing treatment to increase its seizure resistance and wear resistance, Ni ₃ P is generated, reducing the adhesion to the base material. Therefore, in the present invention, even if heat curing treatment is applied,
It is characterized by intervening as an intermediate layer a film that does not generate Ni ₃ P, that is, a hard particle-dispersed plating layer that does not contain phosphorus. If the thickness of this composite dispersed strike plating layer is too thin, sufficient adhesion cannot be achieved. In the present invention, the thickness of the nickel composite dispersed strike plating layer must be 2 μm or more. On the other hand, the nickel composite dispersed strike plating layer a
Increasing the thickness of nickel-cobalt
When the phosphorus composite dispersed plating layer b disappears due to wear and the strike plating layer a acts as a sliding surface, it is inferior to the nickel-cobalt-phosphorus composite dispersed plating layer b, so the outer periphery wear increases quickly and the ring gap gap increases. There is a problem in that the air-tightness of the piston ring deteriorates as the piston ring increases. Therefore, in the present invention, the thickness of the nickel composite dispersed strike plating layer is 20 μm.
The thickness should be 10 μm or less, preferably 10 μm or less. The amount of hard particles dispersed and the particle size are also related to the thickness of the strike plating layer to be formed, but if they are excessively large or large, the plating layer will become brittle and the wear of the sliding mating material will increase. In the present invention, the amount of dispersion is preferably 30% by volume or less, and the particle size is preferably 10 μm or less. If the amount of dispersion is less than 5% by volume and the particle size is less than 0.2 μm, the effect in terms of seizure resistance and wear resistance will not be sufficiently exhibited. The hard particles used here include metal nitrides such _as TiN, _Si3N4 , _Cr2N , metal carbides such as TiC, SiC, _{Cr3C2 ,} metal oxides such as
These include Al ₂ O ₃ TiO ₂ and Cr ₂ O ₃ . A nickel-cobalt-phosphorus composite dispersed plating layer b is further formed on the strike plating layer. In the composite dispersed plating layer b, cobalt has seizure resistance,
Effectively increases wear resistance and corrosion resistance, and increases the toughness and strength of the coating. For this effect, the content is preferably 10% by weight or more. Even if it exceeds 50% by weight, there is no significant change in the effect and it is not economical. Containing phosphorus increases the hardness of the plating base and effectively works to improve wear resistance. For this effect, the content is preferably 2% by weight or more. However, if it is contained in a large amount exceeding 10% by weight, the plating base becomes weak, so it is better to keep the content to 10% by weight or less. The type, amount and diameter of the hard particles are the same as those in the composite dispersed strike plating layer described above. In the second invention, nickel-cobalt-
When forming the phosphorus composite dispersed plating layer b, a major feature is that a solid lubricant is added in addition to hard particles as a dispersant. The rest is the same as the first invention. Solid lubricant particles include molybdenum disulfide,
Tungsten disulfide or boron nitride, etc., and the particle size is 0.2 to 10 μm, similar to hard particles.
If it is less than m, there will be little effect on seizure resistance and wear resistance.
If the thickness exceeds 10 μm, the plated layer becomes brittle and the wear of the sliding mating material increases. If the dispersion amount is less than 5% by volume including the hard particles, there will be little effect on seizure resistance and wear resistance, and if it exceeds 30% by volume, the plated layer will become brittle and the wear of the sliding mating material will increase. (Example) (1) Seizure resistance test Alloy steel SUS440B (C: 0.75-0.95%, Si: 1.0
% or less, Mn: 1.0% or less, P: 0.04% or less,
Ni: 0.60% or less, Cr: 16.0-18.0%, Mo: 0.75
% or less), the particle size is 0.3 to 5μ in the nickel base.
A strike plating layer with a thickness of 5 μm in which 10% by volume of silicon nitride (Si ₃ N ₄ ) is dispersed is formed, and on top of that, a nitrided layer is formed in a nickel base containing 5% by weight of cobalt and 5% by weight of phosphorus. A sample with a composite dispersed plating layer in which 10% by volume of silicon is dispersed.
(A) A strike plating layer with a thickness of 5 μm in which silicon nitride with a particle size of 0.3 to 5 μm is dispersed in a 10% by volume is formed in the nickel matrix, and then cobalt is added on top of the strike plating layer.
Silicon nitride with a particle size of 0.3 to 5 μm and a particle size of 0.3 in a nickel base containing 25% by weight and 5% by weight of phosphorus.
A sample (B) with a composite dispersed plating layer in which 10% by volume of molybdenum disulfide of ~5 μm is dispersed, a sample (C) with a hard chrome plating, and a sample with a nitride layer (D) were prepared. Then, (A) and (B) were heat treated at 400°C for 1 hour to conduct a seizure resistance test. The main parts of the test device are schematically shown in FIGS. 2 and 3. Lubricating oil is supplied to the center of a disc 3 with a diameter of 80 mm that is removably attached to a stator holder 1 through an oiling hole 4 from the back side. Oil is applied. A pressing force is applied to the stator holder 1 with a predetermined pressure toward the right in the figure by a hydraulic device (not shown). A rotor 5 is provided opposite to the disk 3, and is rotated at a predetermined speed by a drive device (not shown). A test piece 7 of 5 mm square and 10 mm high is mounted on a test piece holder 6 removably attached to the rotor 5.
Four are installed concentrically at equal intervals. In such a device, a predetermined pressing force is applied to the stator holder 1 so that the disk (mating material) 3 and the test piece 7 are brought into contact with each other with a predetermined surface pressure. The rotor 5 is rotated while being refueled at a predetermined refueling speed. Using this testing device, a seizure resistance test was conducted in the following manner. That is,
The test piece 7 is slid on the disk 3, and the pressure applied to the stator holder 1 is increased stepwise at regular intervals to generate pressure on the stator holder 1 due to friction between the test piece 7 and the disk 3. Torque (frictional force)
F is applied to the load cell 9 via the spindle 8 shown in FIG. 2, and the change is read by the dynamic strain meter 10. It is assumed that seizure has occurred when the torque F suddenly increases, and the contact surface pressure at that time is taken as the seizure occurrence surface pressure, and the quality of the seizure resistance is judged based on its magnitude. The test conditions are as follows. Friction speed: 8 m/sec Lubricating oil: Motor oil #30 Contact surface pressure: 40 Kg/cm ² to 10 Kg/cm every 3 minutes
Increase by cm ² . The test results are shown in Figure 4. As can be seen from the figure, (A) and (B) of the present invention have significantly improved seizure resistance compared to hard chromium plating or nitrided layers. (2) Adhesion test A steel material (SUS440B) of the same quality as that used for the seizure resistance test, with a nominal diameter x width x thickness of 81 x 1.5 x
We made a 3.3mm piston ring and attached it to the sliding surface.
A strike plating layer with a thickness of 5 μm in which silicon nitride with a grain size of 0.3 to 5 μm is dispersed at 10% by volume is formed in the nickel matrix, and on top of this, 25% of cobalt is added.
10% by volume of silicon nitride with a particle size of 0.3 to 5 μm in a nickel matrix containing 5% by weight of phosphorus.
Forms a dispersed composite dispersed nickel plating layer
(A) A strike plating layer with a thickness of 5 μm in which silicon nitride with a grain size of 0.3 to 5 μm is dispersed in an amount of 10% by volume is formed in a nickel base, and on top of this, 25% by weight of cobalt and 5% by weight of phosphorus are formed. % of silicon nitride with a particle size of 0.3 to 5 μm and a particle size of 0.3
~5μm solid lubricant particles totaling 10% by volume
Forms a dispersed composite dispersed nickel plating layer
(B) Formation of a composite dispersed nickel plating layer in which 10% by volume of silicon nitride with a particle size of 0.3 to 5 μm is dispersed in a nickel base containing 25% by weight of cobalt and 5% by weight of phosphorus (C) Then heat treatment was performed at 400°C for 1 hour to conduct an adhesion test. The main parts of the test device are schematically shown in FIG. 6, in which the opposite ends of the abutment 11a of the piston ring 11 are gripped by gripping tools 12a and 12b, and the gripping tool 12a is fixed. Place the grip tool 1
2b on the opposite side of the abutment of the piston ring 11 11b
A twist test in which the piston ring 11 is rotated as shown by the broken line around the axis and the piston ring 11 is twisted, and the presence or absence of peeling of the plating layer on the opposite side 11b of the abutment of the piston ring 11 is visually observed at each predetermined twist angle. I went there. For each of samples (A), (B), and (C)
40μm, 60μm, 80μm, 100μm, 120μm, 140μm
A plating thickness of m was formed. The test result is the 5th
As shown in the figure. As is clear from Figure 5, samples (A) and (B), in which a strike plating layer was formed on the base and a composite dispersed nickel plating layer was formed thereon, showed good adhesion and did not directly contain phosphorus. In sample (C) with a composite dispersed nickel plating layer, the plating layer peeled off from the base material at a low angle. (3) Actual machine test The composite dispersion plating of the present invention was applied to a steel first pressure ring with a nominal diameter x width x thickness of 81 x 1.5 x 3.3 mm, and a bore diameter of 81 mm was applied to a 4-cylinder water-cooled supercharged gasoline engine. After assembly, high-speed durability was carried out for 100 hours at a rotation speed of 7300 rpm, and the amount of wear on the piston sliding surface and the inner circumferential surface of the cast iron (FC25) cylinder liner was examined, as well as problems such as peeling of the film and occurrence of seizure. On the sliding surface of the piston ring (Material: SUS440B), a 5 μm strike plating layer containing 10% by volume of silicon nitride with a grain size of 0.3 to 5 μm dispersed in a nickel base is formed, and on top of this, 25% by weight of cobalt is applied. , a sample (A) in which a composite dispersed plating layer was formed in which 10% by volume of silicon nitride with a particle size of 0.3 to 5 μm was dispersed in a nickel matrix containing 5% by weight of phosphorus;
Silicon nitride with a particle size of 0.3 to 5 μm is placed in the nickel base.
Strike plating layer dispersed by 10% by volume
A total of 10 hard particles with a particle size of 0.3 to 5 μm and solid lubricant particles with a particle size of 0.3 to 5 μm are formed in a nickel base of 5 μm and further contains 25% by weight of cobalt and 5% by weight of phosphorus. Sample (B) in which a composite dispersed plating layer was formed in which silicon nitride with a particle size of 0.3 to 5 μm was dispersed in a nickel alloy base containing 25% by weight of cobalt and 5% by weight of phosphorus.
A sample (C) forming a composite dispersed plating layer with 10% by volume dispersion was prepared and heat treated at 400°C for 1 hour. In addition, a sample (D) on which a hard chrome plating layer was formed was prepared, and a test was conducted with the plating thickness of (A), (B), (C), and (D) each being 100 μm. The test results are shown in Table 1. The piston ring and cylinder liner of the present invention were in good condition with little wear and no peeling or seizure of the coating. Peeling occurred in those without a strike plating layer on the base.

[Table] (Effects) The present invention has excellent seizure resistance even under severe usage conditions.
This piston ring has a sliding coating with excellent wear resistance, and has good adhesion to the coating and has an improved durability life, and has great industrial value.

[Brief explanation of drawings]

Fig. 1 is a schematic cross-sectional view of a piston ring showing an embodiment of the present invention, Fig. 2 is a partially exploded view showing the main parts of a test device for seizure resistance testing, and Fig. 3 is a cross-sectional view of a piston ring showing an embodiment of the present invention.
-X-ray arrow view, Figure 4 is a diagram showing the results of the seizure resistance test, Figure 5 is a diagram showing the results of the adhesion test, and Figure 6 is a diagram showing the results of the adhesion test.
The figure is a schematic diagram showing a test device for an adhesion test. In the figure; 1... stator holder, 2... sliding surface,
3... Disk, 4... Lubrication hole, 5... Rotor, 6...
...Test piece holder, 7...Test piece, 8...Spindle, 9...Load cell, 10...Dynamic strain meter, 11...
...Piston ring, 11a...Abutment, 11b...
... Opposite side of abutment, 12a, 12b... Gripping tool, a...
...Strike plating layer that does not contain phosphorus, b...Phosphorus-containing composite dispersed plating layer.

Claims (1)

[Scope of Claims] 1. A piston ring for an internal combustion engine, in which a hard metal nitride, metal carbide, or metal oxide with a particle size of 0.2 to 10 μm is contained in a nickel matrix on the outer peripheral sliding surface of the piston ring. It has a composite dispersed nickel strike plating layer with a thickness of 2 to 20 μm in which particles are dispersed at 5 to 30% by volume, and further contains 10 to 50% by weight of cobalt and 2 to 10% by weight of phosphorus. An internal combustion engine having a composite dispersed nickel plating layer in which 5 to 30 volume percent of hard particles of metal nitride, metal carbide, or metal oxide with a particle size of 0.2 to 10 μm are dispersed in a base made of a nickel alloy. piston ring. 2. In a piston ring for an internal combustion engine, 5 to 30 volumes of hard particles of metal nitride, metal carbide, or metal oxide with a particle size of 0.2 to 10 μm are added to the outer peripheral sliding surface of the piston ring in a nickel matrix. It has a composite dispersed nickel plated strike layer with a thickness of 2 to 20 μm in which particles are dispersed in a nickel alloy base containing 10 to 50% by weight of cobalt and 2 to 10% by weight of phosphorus. A composite dispersed nickel mesh in which hard particles of metal nitride, metal carbide, or metal oxide with a diameter of 0.2 to 10 μm and solid lubricant particles with a particle size of 0.2 to 10 μm are dispersed in a total of 5 to 30% by volume. A piston ring for internal combustion engines with a layer.