JPH07188829A - Excellent wear-resistant sliding member made of fe based sintered alloy impregnated with pb for compressor excellent in wear resistance - Google Patents

Abstract

PURPOSE:To provide a sliding member excellent in wear resistance which is a structural member for compressors such as a rotary compressor and scroll compressor. CONSTITUTION:The sliding member for compressors is composed of a Fe base sintered alloy impregnated with Pb which is made by impregnating a Fe base sintered alloy with Pb or Pb alloy. The Fe base sintered alloy has a composition which contains, by weight, 2-20% of >=1 kind among a Mo-Ni alloy, Mo-Co allay and Mo-Ni-Co alloy as a disperse phase forming component and 1-3% C, 0.3-1.5% Si, 8.5-16% Cr, 1-5% Mo, 0.4-3% V, further as necessary, >=1 kind of 0.1-2% Ni and 0.1-8-% Co and the balance Fe with inevitable impurities as base metal forming components, and a vacancy rate of 5-20%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-impregnated Fe-based sintered alloy sliding member for a compressor, which exhibits excellent wear resistance even under severe conditions and has extremely low opponent attack. Is.

[0002]

2. Description of the Related Art Conventionally, it has been specially applied to the manufacture of vane members and roller members, which are structural members of rotary compressors incorporated in refrigerators and air conditioners, and sliding members for compressors such as scroll members of scroll compressors. It is well known that the Fe-based sintered alloy described in Kaihei 1-188649 and many other Fe-based sintered alloys are used.

[0003]

On the other hand, in recent years, various compressors such as rotary compressors and scroll compressors have been remarkably improved in performance and downsized, and along with this, the sliding members, which are these structural members, have been made thinner. Freon R134a replaces Freon R12, which is required to be downsized and has been forbidden to use under more severe conditions, and has recently been a cause of ozone layer depletion.
However, under such a use environment, the conventional sliding members made of various Fe-based sintered alloys have a rapid wear progress and reach a service life in a relatively short time under the present circumstances. is there.

[0004]

Therefore, the present inventors have
From the above-mentioned viewpoint, as a result of research to develop a sliding member for a compressor, which is more excellent in wear resistance, as a result, it was found that the sliding member should be used as a dispersed phase forming component, preferably N.
i: Mo-Ni alloy containing 0.1 to 10%, also C
o: Mo-Co alloy containing 0.1 to 10%, and Ni + Co: Mo-Ni-Co also containing 0.1 to 10%.
1 type or 2 types or more of alloys: 2-20% is contained, and all are C: 1-3% as a base formation component below.
Si: 0.3 to 1.5%, Cr: 8.5
16%, Mo: 1 to 5%, V: 0.4 to 3%, and if necessary, Ni: 0.1 to 2%,
Co: 0.1 to 8%, one or two of which are contained, and the balance consisting of Fe and inevitable impurities (above wt%,% relating to the following composition indicates wt%), and 5
Lead-impregnated Fe-based sintered alloy obtained by impregnating Pb or Pb alloy into a Fe-based sintered alloy having a porosity of ˜20% and a matrix having a martensite structure in which fine carbides are dispersed and precipitated. The sliding member made of the copper-infiltrated Fe-based sintered alloy as a result of the above exhibits excellent wear resistance in practical use under severe conditions, has low opponent attacking property, and is excellent over a long period of time. We obtained the research result that the performance was demonstrated.

The present invention was made on the basis of the above-mentioned research results.
One or more of Ni alloys, Mo-Co alloys, and Mo-Ni-Co alloys: 2 to 20% are contained, and all of the following are C: 1 to 3% as a base forming component,
Si: 0.3 to 1.5%, Cr: 8.5
16%, Mo: 1 to 5%, V: 0.4 to 3%, and if necessary, Ni: 0.1 to 2%,
Co: 0.1 to 8%, one or two of which are contained, and the balance consisting of Fe and inevitable impurities, and a porosity of 5 to 20%, and the matrix is fine. Lead-impregnated Fe obtained by impregnating Pb or Pb alloy into a Fe-based sintered alloy having a martensite structure in which various carbides are dispersed and precipitated.
It is characterized by a compressor sliding member made of a base sintered alloy.

Next, the reasons for limiting the component composition and porosity of the Fe-based sintered alloy constituting the sliding member for a compressor of the present invention as described above will be explained. (A) Dispersed phase forming components These components are preferably Mo-Ni alloys and Mo containing Ni and / or Co in a proportion of 0.1 to 10%.
-Co alloy and Mo-Ni-Co alloy, which is strongly bonded to the base material by diffusion of Ni and / or Co during sintering into the base material and is dispersed in the base material to improve seizure resistance. Although it has a function of suppressing the progress of wear by enabling smooth operation even under practical conditions under various conditions, if its content is less than 2%, the desired effect cannot be obtained on the above-mentioned function, while its content is 20%. If the content exceeds%, the strength will suddenly decrease, so the content was defined as 2 to 20%.

(B) The C component is a solid solution in the base material and strengthens it, and in addition, heat treatments such as quenching and tempering form carbides that are finely precipitated in the base material to increase the hardness of the base material. Therefore, if the content is less than 1%, the desired effect cannot be obtained, and if the content exceeds 3%, the toughness is suddenly reduced. Therefore, the content is determined to be 1 to 3%.

(C) Si The Si component is solid-dissolved in the matrix to improve its hardness and has a deoxidizing action. However, if its content is less than 0.3%, it is desirable for the above action. The effect is not obtained, and on the other hand, if the content exceeds 1.5%, the toughness decreases, so the content was set to 0.3 to 1.5%.

(D) Cr The Cr component is solid-dissolved in the base material to improve the corrosion resistance, and also forms a fine carbide having an average particle size of 10 μm or less to further improve the hardness of the base material and to improve the wear resistance. Although it contributes to the improvement, if the content is less than 8.5%, the desired effect cannot be obtained, while if the content exceeds 16%, the aggression against the opponent is sharply increased. Therefore, the content is determined to be 8.5 to 16%.

(E) Mo The Mo component also forms carbides which are finely dispersed and precipitated in the matrix like Cr to improve the hardness of the matrix, and Ni and / or Co contained in the dispersed phase forming component. Has the effect of promoting diffusion into the matrix at the time of sintering and improving the bonding strength to the matrix, but if its content is less than 1%, the desired effect cannot be obtained for the above-mentioned effect, while If the amount exceeds 5%, the toughness will decrease, so the content was defined as 1 to 5%.

(F) The V V component also has an average particle size of 10 μm, similar to Cr and Mo.
In addition to improving the hardness by forming fine precipitated carbides of m or less, it also has the effect of refining the crystal grains to improve the strength. On the other hand, if the content exceeds 3%, the aggression against the other party will increase, so the content should be 0.4-
It was set at 3%.

(G) Ni and Co These components have the action of forming a solid solution in the matrix to improve the strength and toughness, so they are contained as necessary, but in any case the content is any. If the content is less than 0.1%, the desired effect cannot be obtained. On the other hand, if the content exceeds Ni: 2% and Co: 8%, the hardness of the base material decreases and the wear resistance decreases. Therefore, the content of Ni is 0.1 to 2% and Co is 0.1 to 8%.
I decided.

(H) Porosity If the ratio is less than 5%, lead impregnation is not sufficiently performed,
As a result, not only sufficient airtightness, corrosion resistance, and conformability cannot be ensured, but also the attacking property of the other party appears, while if the ratio exceeds 20%, the wear resistance is sharply reduced. Therefore, the ratio is set to 5 to 20%.

[0014]

EXAMPLES Next, the sliding member for a compressor of the present invention will be specifically described by way of examples. Fe as a raw material powder for forming a water atomized base material having a particle size of 100 mesh or less and having the component composition shown in Tables 1 to 3
Base alloy powders A1 to A17 and B1 to B5, and 10
Has a predetermined average particle size within the range of ˜50 μm, and Table 3
Mo-based alloy powders a to 1 for forming a dispersed phase and a metal Mo powder having the component composition shown in FIG.
Prepare graphite powder of sh or less,
5, the mixture was wet mixed in a ball mill for 72 hours, dried, and then pressed into a green compact at a predetermined pressure within the range of 5 to 7 ton / cm ² , and the green compact was Sintered in vacuum at a predetermined temperature within the range of 1090 to 1120 ° C. for 1.5 hours and then 1000 to 1
Quenching by forced gas cooling from a predetermined temperature in the range of 050 ° C. and tempering heat treatment of holding for 2 hours at a predetermined temperature in the range of 500 to 600 ° C. are repeated twice, and the martensite matrix has an average particle size of 10 μm. By uniformly precipitating the following fine carbides, they have substantially the same compositional composition as the compounding composition, both width: 20 mm x length: 17 mm
× Thickness: a rectangular plate having a thickness of 4 mm, and one end face in the longitudinal direction which abuts the roller piston as a mating member has a curved surface of R4 to form a vane member shape of the rotary compressor, and the holes shown in Tables 4 and 5 also. Fe with a rate
A conventional Fe-based sintered alloy sliding member composed of a base-based sintered alloy and an Fe-based sintered alloy having a composition corresponding to the Fe-based sintered alloy described in JP-A-1-188649. (Hereinafter, referred to as conventional sintered sliding member) 1 to 5, and the above-mentioned F except that the conventional sintered sliding members 1 to 5 are excluded
The combination shown in Tables 4 and 5 was applied to the e-based sintered alloy in a nitrogen atmosphere with a pressure of 8 kg / cm ² applied to the bath surface.
The lead-impregnated Fe-based sintered alloy sliding member according to the present invention is obtained by impregnating lead in a bath of pure lead or a Pb alloy having a composition of Pb-5% Sn heated to 500 ° C. under the condition of immersion and holding for 1 hour. Hereinafter referred to as lead-impregnated sintered sliding member of the present invention) 1 to 17
Were manufactured respectively.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

[Table 4]

[0019]

[Table 5]

Next, the lead-impregnated sintered sliding members 1 to 17 of the present invention and the conventional sintered sliding members 1 to 5 thus obtained were
Compressor size: inner diameter 41mm x width 20mm, roller piston material: FC300 heat treated material, roller piston dimension: outer diameter 32mm x width 20mm, built into a rotary compressor, refrigerant used: Freon 134a, roller piston The actual wear test was carried out under the conditions of pressing force: 18 kgf, rotation number of roller piston: 1250 rpm, and test time: 600 hours, and the maximum wear depth was measured. The results of these measurements are shown in Tables 4 and 5 together with the maximum wear depth of the roller piston which is the counterpart member.

[0021]

From the results shown in Tables 4 and 5, the lead-impregnated sintered sliding members 1 to 17 of the present invention are much more excellent than the conventional sintered sliding members 1 to 5 in a severe corrosive environment. It is clear that it has excellent wear resistance and its opponent's aggressiveness is extremely low. As described above, the lead-impregnated Fe-based sintered alloy sliding member for a compressor according to the present invention has excellent wear resistance while maintaining extremely low opponent attack property even in practical use under severe conditions. It can be fully utilized to reduce the size and weight of compressors such as rotary compressors and scroll compressors, as well as to improve their performance.

Claims (2)

[Claims] 1. A dispersed phase forming component contains one or more of Mo—Ni alloys, Mo—Co alloys, and Mo—Ni—Co alloys: 2 to 20%, both of which are included below. Contains C: 1-3%, Si: 0.3-1.5%, Cr: 8.5-16%, Mo: 1-5%, V: 0.4-3% as a matrix forming component. However, a Fe-based calcined bond having a composition of Fe and unavoidable impurities (more than wt%) and a porosity of 5 to 20%, and a base material having a martensite structure in which fine carbides are dispersed and precipitated. A lead-impregnated Fe-based sintered alloy sliding member for a compressor, which is excellent in wear resistance, characterized by comprising a lead-impregnated Fe-based sintered alloy obtained by impregnating gold with Pb or a Pb alloy. 2. The dispersion phase-forming component contains one or more of a Mo—Ni alloy, a Mo—Co alloy, and a Mo—Ni—Co alloy: 2 to 20%, both of which are included below. Contains C: 1-3%, Si: 0.3-1.5%, Cr: 8.5-16%, Mo: 1-5%, V: 0.4-3% as a matrix forming component. In addition, Ni: 0.1 to 2%, Co: 0.1 to 8%, containing one or two of them, and the balance consisting of Fe and inevitable impurities (above wt%), And a Fe-based sintered alloy having a porosity of 5 to 20% and a base material having a martensite structure in which fine carbides are dispersed and precipitated, Pb
Alternatively, a sliding member made of a lead-impregnated Fe-based sintered alloy for a compressor, which has excellent wear resistance, is constituted by a lead-impregnated Fe-based sintered alloy impregnated with a Pb alloy.