JPH07238345A - Sliding material - Google Patents

Abstract

PURPOSE:To produce a sliding material having excellent wear resistance. CONSTITUTION:This sliding material has a composition consisting of, by weight, 30-70% Cu, 0.2-7% Al, and the balance Fe with inevitable impurities and further containing, as alloy components, 3-9% Cr or further 0.01-1% C. By this method, the sliding material, excellent in plastic workability and having excellent wear resistance, can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material having excellent wear resistance for various sliding parts of industrial equipment.

[0002]

2. Description of the Related Art A general sliding wear phenomenon progresses through a process as shown in FIG. That is, in the initial stage of the start of sliding, the wear rapidly progresses, and when the wear surface becomes familiar with the deteriorated layer, the wear speed becomes low and the wear becomes steady wear.

Therefore, in order to improve the wear resistance of the material, the period of initial wear having a high wear rate as shown in a to b shown in FIG. 1 is made as short as possible and the steady wear having a low wear rate is swiftly changed. Is an effective means. When various machines such as automobiles are newly introduced, so-called "run-in" is performed under slow conditions such as low speed and low load, and so-called "familiar" is added to quickly end the initial wear, and then the Driving is a specific example. Considering this method of improving wear resistance from the viewpoint of material development, it is effective to develop a material that transitions from initial wear to steady wear as quickly as possible.

It has been known from many past experiences that a combination of two sliding materials has a great influence on a period until a transition to steady wear, that is, a familiar running period. Generally, sliding between metals of the same kind shows bad results such as burning and is hard to shift to steady wear, and is called "togane" and its use is avoided. Therefore, it is common for sliding systems to use a combination of different materials.

One of the sliding materials is often made of steel typified by bearing steel from the viewpoint of strength characteristics and the like. Empirically, a Cu-based alloy, a lead-based alloy, a Teflon-based resin, or the like is suitable as a material for the sliding, and it is known that the initial wear changes to the steady wear relatively quickly. These materials are selected and used according to necessary conditions such as operating temperature and atmosphere.

Past literature (Lubrication, 30, 9 (1985)
679), in order to shift from initial wear to steady wear, it is necessary to form a surface layer in which two sliding materials are finely mixed with each other.
It is described that the sliding of u and Fe is excellent. Further, the same document describes a material which facilitates mixing of Cu and Fe by using a laminated material of Cu and Fe (sandwich structure) for one of the sliding members and quickly forms a surface layer.

[0007] However, this material has problems such as adhesion method between laminated layers, such as insufficient strength, a problem that adhesive acts as an impurity and exerts a bad influence, or uneven wear such that the abrasion rate between laminated materials is different, Since they are combined in a plate shape, there is a problem that the formation time of the mixed layer is not always sufficiently short, etc., and it was insufficient as a practical material.

From the techniques of the above-mentioned documents, it is easily inferred that a material having a structure in which Cu and Fe are finely mixed is suitable as a material intended to slide on an Fe-based material. It is difficult to manufacture a material having such a structure, and even if it can be manufactured, plastic processing is impossible because the fine structure is destroyed and collapses, and it has not been a practical material.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a material having excellent sliding properties with various Fe-based materials such as bearing steel which is generally used in various industrial equipments which are subject to sliding wear. It is what

[0010]

The present invention is intended to achieve the above object and has the following construction. That is, Cu: 30 to 70% by weight, A
l: 0.2 to 7%, the balance being a sliding material consisting of Fe and unavoidable impurities, further containing 3% to 9% of Cr as an alloy component, or 0.01 to 0.01% of C.
A sliding material containing 1%.

The material of the present invention has a structure in which Cu and Fe are finely mixed and mixed, and when sliding with an Fe-based material, it rapidly changes from initial wear with a high wear rate to steady wear with a low wear rate. Since it is transferred, it has excellent wear resistance. Fe and Cu are elements that cause two-phase separation, and they hardly form a solid solution at room temperature, and even at 1000 ° C., the solid solution of Fe in Cu is 3% or less. Therefore, the alloy obtained by mixing these two elements becomes a mixture of Fe phase and Cu phase, and it is possible to obtain the material having the structure proposed by the present invention.

However, simply mixing Fe and Cu,
In the material obtained by melting, the mechanical properties of the Fe phase and the Cu phase, such as strength, hardness, elastic modulus, etc., are too different, so when plastic working is attempted, phase separation occurs and the structure collapses. , Not a practical material. Since wear on the sliding surface of the metal material is caused by fracture due to plastic deformation, such a material that simply mixes Fe and Cu accelerates the wear.

In this regard, the present inventors have found that Cu--Fe--Cr--Al alloys are excellent as high temperature oxidation resistant materials, and
It has been previously proposed that the plastic workability is improved by adding 1 (Japanese Patent Laid-Open No. 64-73034). As a result of various experiments conducted by the present inventors as a sliding material, the present invention has been completed.

The present invention will be described in detail below. First,
The amount and function of each additive element will be described. Cu is 30
~ 70 wt% is good. If it is less than 30%, the amount of Cu is not sufficient, and if it is 70% or more, the amount of Fe is relatively insufficient. Therefore, it takes time to form a surface layer which is a mixture of Cu and Fe, and the wear rate is rapidly increased. It is not possible to shift to low steady wear. When Cu is preferably soft such as a bearing metal or when it is desired to have electric conductivity like a current collecting material, the proportion of Cu is increased, and strength is required as in mechanical structural parts. If it does, the proportion of Fe can be relatively increased by decreasing it.

Al is added in order to improve the plastic workability of the material and to prevent the strong adhesion of steel, which is a material for sliding, to more easily form the mixed layer. If it is less than 0.2%, the amount is not sufficient, and if it is 7% or more, an intermetallic compound is formed with Cu or Fe to cause hard brittleness and reduce wear resistance, so 0.2 to 7% is preferable. .

[0016] Cr improves the rust resistance, and particularly forms a solid solution in the Fe phase to improve the rust resistance of the Fe phase. Further, since it contributes to oxidation resistance at high temperatures, it is desirable to add Cr as an alloying element when it is used in a sliding system used in an environment where oxidation or corrosion easily occurs. The amount of Cr is preferably 3 to 9% by weight, and if it is less than 3%, the effects of rust resistance and oxidation are small. On the other hand, if it exceeds 9%, the material becomes brittle and the workability is reduced.

C is incorporated into the Fe phase to increase the strength.
If the amount of C is 0.01% or less, it has no effect and 1%
In the above case, the material becomes hard and brittle, so it is preferably in the range of 0.01 to 1 wt%.

Next, a method for manufacturing the alloy will be described. Each metal is blended and melted so that it falls within the composition range of the alloy of the present invention. The melting temperature is preferably 1400 ° C. or higher in order to mix the added metals uniformly. The atmosphere can be air, vacuum, or a non-oxidizing gas atmosphere. After being heated to 1400 ° C. to 1700 ° C. and melted, it is poured into a mold and cooled, but it is preferable to use a mold with riser to prevent defects such as shrinkage cavities and pipes from occurring in the ingot.

Thereafter, hot rolling and cold rolling are performed to form a plate having a thickness suitable for producing a desired sliding component. The temperature during hot rolling is appropriately in the range of 850 to 1050 ° C, and the rolling reduction and the like may be carried out in the same manner as in the production of ordinary steel sheets. Cold rolling can be easily performed without special care. When used as a wire rod, forging is performed instead of rolling and wire drawing is performed with a die.

[0020]

EXAMPLES The present invention will be further described below based on examples. Five kinds of materials whose composition is shown in Table 1 were made as prototypes, and sliding wear characteristics were evaluated by a pin-on-disk type wear tester. The material of each example is shown in Table 1.
After mixing in the weight ratio shown in, melted in a high-frequency melting furnace to obtain an ingot, and hot rolled at 1000 ° C for 5 mm.
A test piece was prepared by machining after the thickness was used.

The sliding speed was 62.8 mm / s and the test was conducted in the atmosphere. As a comparative example, carbon steel (JIS / S45
C) and oxygen free Cu are covered. These materials were used as pin test pieces, and the disk test piece as a sliding partner was carbon steel (JIS / S45C).

Table 1 Alloy composition of the sample (% by weight) Element Fe Cu Al Cr C Example 1 68 30 20 0 Example 2 50 44 6 0 0 Example 3 28 70 2 0 0 Example 4 49 44 2 5 0 Example 5 53.5 44 2 0 0.5

FIG. 2 shows the amount of wear when tested under a test load of 8.8 N at room temperature. Examples 1-3 and carbon steel and Cu were tested as comparative examples. Sliding between carbon steels is unlikely to cause steady wear with a low wear rate, and when Cu is used as a pin, it takes a relatively long time to shift from initial wear to steady wear. On the other hand, Examples 1 to 3 according to the present invention
Shows that after the start of sliding, it quickly shifts to mild steady wear and exhibits good wear resistance.

FIG. 3 is a test of Examples 2 and 4 at a high temperature of 200 ° C. Under the sliding conditions in which the oxidation is accelerated as described above, it is understood that the material to which Cr is added as in Example 4 is superior in wear resistance.

FIG. 4 shows Examples 2 and 5 tested under a high load of 28N. Under such a sliding condition where mechanical strength is required, it can be seen that the material containing C is more excellent in wear resistance.

[0026]

As described above, according to the present invention, it is possible to provide a sliding material having excellent plastic working characteristics and good wear resistance.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a general idea of progress of sliding wear and improvement of wear resistance.

FIG. 2 shows the results of a wear test of three examples of the sliding material of the present invention and Cu and carbon steel as comparative examples by a pin-on-disc type wear tester at room temperature and in the atmosphere.

FIG. 3 shows two examples of sliding materials of the present invention, 200
It is the figure which showed the abrasion resistance of the material which carried out the abrasion test with the pin-on-disc type abrasion tester in high temperature of (degreeC), and was excellent in abrasion resistance.

FIG. 4 shows two examples of sliding materials of the present invention, 28N
FIG. 3 is a view showing that a material added with C was subjected to a wear test by a pin-on-disk type wear tester under a high load of No. 1, and that the material to which C was added has excellent wear resistance.

Claims (4)

[Claims] 1. Cu: 30 to 70% by weight, Al:
A sliding material consisting of 0.2 to 7% and the balance being Fe and inevitable impurities. 2. Cr as an alloy component, further containing 3 to 9% by weight.
The sliding material according to claim 1, which contains. 3. The sliding material according to claim 1, further containing 0.01 to 1% by weight of C as an alloy component. 4. The sliding material according to claim 2, further comprising 0.01 to 1% by weight of C as an alloy component.