JP2004107678A - Wear-resistant sliding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wear-resistant sliding member excellent in wear resistance and scuffing resistance, also which has low attackability against the mating member, and thus can be utilized for a large-sized marine diesel engine which is used under severe conditions. <P>SOLUTION: The wear-resistant sliding member (10) comprises a base material (M) and a sprayed coating (C) formed by thermally spraying a mixed powder comprising, by mass, 30 to 70% of a molybdenum powder, 10 to 40% of a nickel-chromium alloy powder, 3 to 40% of a ceramic powder, and 2 to 15% of a solid lubricant onto a sliding surface of the base metal. <P>COPYRIGHT: (C)2004,JPO

Description

【００１７】
溶射皮膜はプラズマ溶射によるものである。その溶射条件は次のとおりである。　　　使用ガン：スルザーメテコ社製９ＭＢプラズマ溶射ガン
電圧：６０〜７０Ｖ
電流：５００Ａ
【００１８】
各試験片について、スカッフ試験及び摩耗試験を実施した。
【００１９】
スカッフ試験
図２に示す回転式平面滑り摩擦摩耗試験により、各試験片のスカッフ限界面圧を測定した。一定速度で回転する相手材１２の回転面に試験片１１を一定時間所定の面圧（Ｐ）で圧接し、スカッフが発生した時の面圧を限界面圧とした。面圧操作は、初期面圧を２．４５ＭＰａとして、３０分後に面圧を４．９ＭＰａ、それから５分毎に０．９８ＭＰａずつ漸次増加させていく方法で行われた。
【００２０】
試験条件は、以下のとおりである。
滑り速度：５ｍ／ｓｅｃ
潤滑油：ＳＡＥ３０＋白灯油（１：１）
油量：無給油、初期塗布のみ
相手材：ターカロイ（日本ピストンリング（株）の商品名として知られているボロン鋳鉄）
【００２１】
測定結果は図３に示すとおりである。実施例の試験片Ｎｏ．３〜Ｎｏ．１４のスカッフ限界面圧は７．８〜８．８ＭＰａの範囲であり、比較例の試験片Ｎｏ．１及びＮｏ．２のスカッフ限界面圧は６．６〜７．８ＭＰａの範囲であるから、実施例の耐スカッフ性は比較例と同等もしくはそれを上回る。
【００２２】
耐摩耗試験及び耐相手材攻撃性試験
図２に示す回転式平面滑り摩擦摩耗試験により、各試験片の摩耗深さと相手材の摩耗深さを測定した。一定速度で回転する相手材１２の回転面に試験片１１を一定時間所定の面圧（Ｐ）をかけて、試験をした。潤滑油は回転する相手材１２に滴下した。
【００２３】
試験条件は、以下のとおりである。
滑り速度：６ｍ／ｓｅｃ
面圧：６ＭＰａ
潤滑油：スピノックスＳ−２軸受油（日本石油株式会社の商品名として知られている軸受油）
油温：６０±１０℃
油量：１０^{− ４}ｍ^３／ｍｉｎ
試験時間：１００時間
相手材：ターカロイ（日本ピストンリング株式会社の商品名として知られているボロン鋳鉄）
【００２４】
測定結果は図４に示すとおりである。実施例の試験片Ｎｏ．３〜Ｎｏ．１４の摩耗深さ（リング材摩耗量）は１２．６〜１７．１μｍの範囲であり、比較例の試験片Ｎｏ．１及びＮｏ．２の摩耗深さは１７．５〜２２．３μｍの範囲であるから、実施例の耐摩耗性は比較例よりも良好である。また、実施例の試験片Ｎｏ．３〜Ｎｏ．１４の相手材摩耗深さ（ライナ材摩耗量）は１．１〜２．１μｍの範囲であり、比較例の試験片Ｎｏ．１及びＮｏ．２の相手材摩耗深さは２．８〜４．３μｍの範囲であるから、実施例の耐摩耗性及び相手材攻撃性は比較例よりも著しく良好である。
【００２５】
【発明の効果】
上記のとおり、本発明の耐摩耗性摺動部材は、摺動面に形成した溶射皮膜が、モリブデン、ニッケル−クロム合金、セラミックス、固体潤滑剤の各粉末からなる混合粉末を溶射してなり、従来のものに比べると、耐摩耗及び耐スカッフ性に優れるが、相手攻撃性は低いので、より厳しい条件下で使用される摺動部材、例えば、高性能大型舶用ディーゼルエンジンのピストンリング等に使用することができるだけでなく、エンジン全体の寿命を延ばすことができるという格別の効果を奏する。
【図面の簡単な説明】
【図１】本発明に係るピストンリングの要部断面図、
【図２】摩擦試験に用いた回転式平面滑り摩擦摩耗試験機の略図、
【図３】スカッフ試験の結果を示す図、
【図４】摩耗試験の摩耗量測定結果を示す図、
【符号の説明】
１０：ピストンリング
１１：固定片
１２：回転片
Ｃ：溶射皮膜
Ｍ：母材
Ｐ：面圧[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sliding member such as a piston ring and a cylinder liner used for an internal combustion engine.
[0002]
[Prior art]
In recent years, higher output and higher performance of internal combustion engines have been demanded, and accordingly, sliding members such as piston rings and cylinder liners have been exposed to higher temperatures and have been used in more severe environments. For this reason, the sliding member is required to have better wear resistance and scuff resistance. Conventionally, hard chrome plating has been used in order to improve the wear resistance of the sliding member. However, hard chrome plating is inferior in scuff resistance, and is therefore shifting to surface treatment by thermal spraying. For example, JP-A-6-221438 proposes a plasma sprayed coating made of molybdenum, a nickel-chromium alloy, and fine chromium carbide as a piston ring having excellent wear resistance and scuff resistance.
[0003]
[Problems to be solved by the invention]
However, the thermal spray coating containing chromium carbide as a fine ceramic powder has a large sliding resistance, and has a problem that it attacks and wears a mating material such as a cylinder liner.
[0004]
The present invention has been made to solve this problem, and its object is to provide a thermal spray coating of a sliding member having excellent wear resistance and scuff resistance, which has a relatively small sliding resistance, The aim is to provide something that is less aggressive.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a means adopted by the present invention is that a base material sliding surface of a sliding member includes molybdenum powder 30 to 70 mass%, nickel-chrome alloy powder 10 to 40 mass%, ceramic powder 3 The sprayed coating (C) was formed by spraying a mixed powder comprising ４０40% by mass and 2-15% by mass of a solid lubricant powder.
[0006]
The reasons for limiting this component are as follows.
[0007]
When the ratio of the molybdenum powder is less than 30% by mass, the coating layer is inferior in scuff resistance, and when the ratio exceeds 70% by mass, sufficient hardness cannot be obtained. Therefore, the ratio of the molybdenum powder is 30 to 70% by mass.
[0008]
When the ratio of the nickel-chromium alloy powder is less than 10% by mass, the coating layer cannot obtain sufficient toughness, and when the ratio exceeds 40% by mass, the scuff resistance is poor. % By mass.
[0009]
Ceramic powder is chromium oxide or chromium carbide. If the ratio is less than 3% by mass, the coating layer cannot obtain sufficient hardness, and if it exceeds 40% by mass, it becomes too hard and attacks the partner material. The ratio of the ceramic powder is 3 to 40% by mass.
[0010]
The solid lubricant powder is manganese sulfide, molybdenum disulfide or calcium fluoride. When the ratio is less than 2% by mass, the lubricating effect cannot be sufficiently obtained. When the ratio exceeds 15% by mass, the coating layer becomes brittle. Therefore, the ratio of the solid lubricant powder is set to 2 to 15% by mass.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described based on a piston ring shown in FIG.
[0012]
The piston ring 10 of FIG. 1 has a thermal spray coating C on the outer peripheral sliding surface of the base material M. This thermal spray coating C is composed of 30 to 70% by mass of molybdenum powder, 10 to 40% by mass of nickel-chrome alloy powder, 3 to 40% by mass of chromium oxide or chromium carbide ceramic powder, manganese sulfide or molybdenum disulfide or calcium fluoride. It is formed by spraying a mixed powder composed of 2 to 15% by mass of a solid lubricant powder.
[0013]
This thermal spray coating C has excellent scuff resistance and abrasion resistance, and includes a solid lubricant powder, so that it has relatively low sliding resistance and low opponent aggression.
[0014]
【Example】
Hereinafter, the wear-resistant sliding member of the present invention will be described by various tests performed on the examples and the known comparative examples.
[0015]
The mixed powder of the components shown in Table 1 was plasma-sprayed on the base material of the same cast iron material for piston rings to form 14 types of 300 μm-thick thermal sprayed coatings, which were used as 14 types of examples and comparative examples test pieces. . The two test pieces No. 1, No. No. 2 is a known comparative example proposed in the above-mentioned publication, and twelve test piece Nos. 3, no. 4, no. 5, no. 6, no. 7, no. 8, No. 9, No. 10, no. 11, No. 12, No. 13, No. 14 is an embodiment of the present invention.
[0016]
Table 1

[0017]
The thermal spray coating is obtained by plasma spraying. The spraying conditions are as follows. Gun used: 9MB plasma spray gun manufactured by Sulzer Metco Voltage: 60-70V
Current: 500A
[0018]
For each test piece, a scuff test and a wear test were performed.
[0019]
Scuff test The scuff limit surface pressure of each test piece was measured by a rotary plane sliding friction wear test shown in FIG. The test piece 11 was pressed against the rotating surface of the counterpart material 12 rotating at a constant speed with a predetermined surface pressure (P) for a certain period of time, and the surface pressure when scuffing occurred was defined as the limit surface pressure. The surface pressure operation was performed by setting the initial surface pressure to 2.45 MPa, increasing the surface pressure after 30 minutes to 4.9 MPa, and gradually increasing the surface pressure by 0.98 MPa every 5 minutes.
[0020]
The test conditions are as follows.
Sliding speed: 5m / sec
Lubricating oil: SAE30 + white kerosene (1: 1)
Oil quantity: No lubrication, only initial application Counterpart material: Tarkalloy (boron cast iron known as Nippon Piston Ring Co., Ltd.)
[0021]
The measurement results are as shown in FIG. The test piece No. of the example was used. 3-No. The scuff limit contact pressure of Scuff No. 14 is in the range of 7.8 to 8.8 MPa, and the test piece No. of the comparative example. 1 and No. 1 Since the scuff limit surface pressure of No. 2 is in the range of 6.6 to 7.8 MPa, the scuff resistance of the example is equal to or higher than that of the comparative example.
[0022]
Wear Resistance Test and Counterpart Material Attack Resistance Test The wear depth of each test piece and the wear depth of the counterpart material were measured by a rotary plane sliding friction wear test shown in FIG. The test was performed by applying a predetermined surface pressure (P) to the test piece 11 for a predetermined time on the rotating surface of the counterpart material 12 rotating at a constant speed. The lubricating oil was dropped on the rotating counterpart material 12.
[0023]
The test conditions are as follows.
Sliding speed: 6m / sec
Surface pressure: 6MPa
Lubricating oil: Spinox S-2 bearing oil (bearing oil known as a trade name of Nippon Oil Corporation)
Oil temperature: 60 ± 10 ° C
Oil ^{quantity: 10} - ⁴ m 3 / min
Test time: 100 hours Mate: Tarcaloy (boron cast iron known as Nihon Piston Ring Co., Ltd.)
[0024]
The measurement results are as shown in FIG. The test piece No. of the example was used. 3-No. The wear depth (amount of wear of the ring material) of No. 14 was in the range of 12.6 to 17.1 μm, and the test piece No. of the comparative example. 1 and No. 1 Since the wear depth of No. 2 is in the range of 17.5 to 22.3 μm, the wear resistance of the example is better than that of the comparative example. In addition, the test piece No. 3-No. The wear depth of the mating member (liner member wear amount) of Sample No. 14 is in the range of 1.1 to 2.1 μm. 1 and No. 1 Since the wear depth of the mating material of No. 2 is in the range of 2.8 to 4.3 μm, the wear resistance and the aggressiveness of the mating material of the examples are significantly better than those of the comparative examples.
[0025]
【The invention's effect】
As described above, in the wear-resistant sliding member of the present invention, the sprayed coating formed on the sliding surface is formed by spraying a mixed powder of molybdenum, nickel-chromium alloy, ceramics, and a powder of solid lubricant, Compared to conventional ones, it is superior in wear resistance and scuff resistance, but has low aggressiveness against opponents, so it is used for sliding members used under more severe conditions, such as piston rings for high performance large marine diesel engines Not only can extend the life of the engine, but also has a special effect.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of a piston ring according to the present invention,
FIG. 2 is a schematic view of a rotary plane sliding friction and wear tester used for a friction test;
FIG. 3 is a diagram showing the results of a scuff test.
FIG. 4 is a view showing a wear amount measurement result of a wear test;
[Explanation of symbols]
10: Piston ring 11: Fixed piece 12: Rotating piece C: Thermal spray coating M: Base material P: Surface pressure

Claims (3)

On the sliding surface of the base material (M) of the sliding member (10), 30 to 70% by mass of molybdenum powder, 10 to 40% by mass of nickel-chrome alloy powder, 3 to 40% by mass of ceramic powder, and solid lubricant powder 2 A wear-resistant sliding member, characterized in that a sprayed coating (C) is formed by spraying a mixed powder of up to 15% by mass. The wear-resistant sliding member according to claim 1, wherein the ceramic powder is chromium oxide. The wear-resistant sliding member according to claim 1 or 2, wherein the solid lubricant powder is calcium fluoride.

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