JPS63303031A - Vane for compressor - Google Patents

Abstract

PURPOSE:To obtain a vane material having excellent wear resistance and scuffing resistance by producing the vane material for a compressor with alloy cast iron contg. Cr and other elements to be added. CONSTITUTION:The alloy cast iron contg., by weight, 2.5-3.7% C, 1.0-2.0% Si, 0.5-1.0% Mn, 10-20% Cr, 0.3-0.7% Ni, <0.3% P and <0.1% S or furthermore contg. one or more kinds among 1-10% W, Mo, V, Nb and Ta is used as the vane material for a rotary compressor. The vane material having the structure in which the matrix converts into pearlite in an as-cast state and converts into martensite by quenching and in which hard metallic carbides involving the Cr carbide as the essential component are uniformly deposited, and having excellent wear resistance and scuffing resistance at the time of high loading can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a compressor vane made of cast iron material with high wear resistance and scuffing resistance.

[Prior Art] Currently, rotary compressors used in household electric appliances are becoming lighter and smaller, and in order to meet the demands for lower costs and higher performance, improvements are also being sought in the materials used to form each component. In other words, as shown in Fig. 1, a rotary compressor is composed of a case 10, a housing 11, vanes 12 housed in grooves in the housing, rollers 13, etc. Among these, especially in recent years, high-load Therefore, the vane 12 is required to have wear resistance.

Currently, many vane materials are used, such as hardenable cast iron, steel materials such as 5KH51, iron-based solid phase sintered alloys, and carbon.

[Problems to be solved by the invention] However, when the vane material is made of hardenable cast iron or steel, scuffing and wear occur under high loads.
In addition, the number of processing steps is large, resulting in high costs.

In addition, vanes made of iron-based solid-phase sintered alloys have many continuous pores, so they can cause problems such as dirt from oil quenching, residual grinding fluid, and abrasive grains, and the formation of an oil film due to lubricating oil escaping from the pores during sliding. It was necessary to perform a sealing treatment because of the disadvantages such as being difficult to clean. Moreover, the material strength was low and the wear resistance was also poor.

Alternatively, carbon vanes, which are currently used as having the highest wear resistance, have problems with water content and processing, making them expensive.

Therefore, the purpose of the present invention is to provide a vane that exhibits excellent performance.
The object of the present invention is to provide a vane that has excellent wear resistance, scuffing resistance, and high strength, especially under high loads, and is inexpensive to manufacture.

[Means for solving the problems] The present invention has a component composition of C: 2.5 to 3.7% by weight.
, Si: 1.0-2.0%,) In: 0.5-1.
0%, Cr: 10-20%, Ni: 0.3-0.7%,
P: 0.3% or less, S20, 1% or less, cLJ: Hi required L; TW, ) to, vlNb, Ta: 1 to 10% with one or more types, the balance is unavoidable with Fe The object of the present invention is to provide a vane made of a cast iron material containing impurities, in which carbide mainly composed of Cr is uniformly precipitated in a pearlite or martensite matrix, thereby solving the above-mentioned problems.

In order to reduce manufacturing costs, the compressor vane of the present invention is preferably integrally molded by casting using a shell mold or lost wax mold.

In addition, cast iron has sufficiently excellent wear resistance when it is as-cast and has a pearlite base, but after quenching it with a hardened martensite base, a mixed base of pearlite and martensite, or after quenching, a hard nitride compound layer is formed on the surface by nitriding. If it is formed, extremely high wear resistance can be obtained.

The reason why the component composition was limited as described above will be explained below.

The C component solidly dissolves in the base, strengthens it, and forms a solid solution (Cr-E).
e) Forms hard carbides mainly composed of Cr, such as 7C3, and other carbides, which have the effect of improving wear resistance.

If it is less than 2.5%, the amount of precipitated carbides will be insufficient and wear resistance will not be obtained, and if it exceeds 3.7%, the amount of precipitated carbides will be excessive, resulting in excessive aggressiveness to the mating material and poor workability. It also gets worse.

The Si component is added as an inoculant, but if it is less than 1.0%, the melting point of the molten metal will become high, resulting in poor water flow during casting.

Moreover, if it exceeds 2.0%, the formation of carbides is inhibited and granular graphite is precipitated, resulting in a decrease in wear resistance.

A part of the Mn component forms a carbide, and a part of the Mn component forms a solid solution in the matrix to promote pearlite formation of the matrix structure and improve hardenability. If it is less than 0.5%, these effects cannot be obtained, and if it exceeds 1.0%, an excessive amount of carbide will precipitate, or if the base is martensite, tempering embrittlement of the base around the carbide will occur, and the material will deteriorate. embrittle.

The Cr component solid-solves in the matrix to strengthen it and improve heat and corrosion resistance. In addition, the cast iron material of the present invention is characterized by a high Cr content, and is characterized by a high Cr content such as (Cr I Fe) 703.
It forms a carbide mainly composed of r, which has high hardness and exhibits excellent wear resistance. If it is less than 10%, the amount of carbide precipitated is small and the wear resistance is poor.

Moreover, if it exceeds 20%, the base tends to become ferrite, resulting in a decrease in wear resistance.

The Ni component has the effect of densifying and strengthening the matrix and improving hardenability. If it is less than 0.3%, these effects cannot be obtained, and if it exceeds 0.7%, the effect is saturated and it becomes economically disadvantageous.

The P component is 0.3% or less, and the S component is 0.1% or less, but if both exceed these ranges, the material becomes brittle.

If the cast iron material of the present invention is manufactured as a vane from the above components and the remaining re and unavoidable components that are normally included in cast iron, it will become a pearlite base in the as-cast state, and then it will become a martensite base by quenching or surface hardening by nitriding treatment. Good sliding properties with rollers are achieved. However, if extremely high wear resistance is required due to the working environment with these mating materials, W, No, VlNblTa
1 to 1 or more carbide-forming elements such as
Contain 10%. If it is less than 1%, there will be no effect of improving wear resistance, and if it exceeds 10%, it will be economically disadvantageous.

[Example] The present invention will be explained below using examples.

(Test method) Vanes made of the cast iron material of the present invention were manufactured by casting molten metal at 1400 to 1500°C with varying compositions into lost wax molds, and as shown in Table 1, as-cast vanes (No.
1>, The entire surface was oil quenched at 900℃ for 60 minutes (N
α2), quenched and then nitrocarburized in a salt bath at 580°C for 90 minutes (Nα3), and 5UP9.5CH435, S, which is conventionally used as a comparison material, and H51,5US.
We manufactured vanes made of 440C (steel material), hardenable cast iron, and in-phase sintered material.

Base structure IA observation, hardness measurement,
A basic wear test was conducted. The wear test is an Amsura set wear test, in which each of the above vanes is processed into a flat plate shape as a fixed piece in a plane contact upward wear tester, and these fixed pieces are used as a mating roller material, that is, Ni-Cr-No cast iron (C:
3.31, Si: 2.24, Mn: 0.63, P:
0.06, S: 0.04, Ni: 0.21, cr:
o, as, Ho: 0.32 (weight% or more) was pressed against a roll-shaped sample, and the roll-shaped sample was rotated while constantly supplying lubricating oil to the pressed surface.

The test conditions are as follows.

Load...100Kg, circumferential speed...1m/S, lubricant...
...Suniso 4GD1D, oil temperature...25℃, test time・
...20 hours.

The amount of wear on the fixed piece and the rotating piece was measured by the above method, and the measured values shown in Table 1 were 1q.

In addition, a scuffing resistance test was also conducted using the Amsla set abrasion test. The sample was the same as the above wear test,
While rotating the roll-shaped sample at a circumferential speed of 1.13 m/s, the pressing load of the fixed piece was set at 10 Kfl at the start, and the load was increased by 20 Kg every 2 minutes, and from 50 Kg or more, the load was increased by 1 ONg, and this caused the load that caused scuffing. The measured values shown in Table 1 were obtained, with the value being the scuffing limit load.

(Test Results) As can be seen from the measurement results shown in Table 1, when the vane of the present invention is used, the amount of wear is smaller and the scuffing limit load is larger than when comparative materials are used for both the vane material and the roller material. . In addition, good results were obtained in the following order: nitrided material, quenched material, and as-cast material. In the case of nitrided materials, the base is softened by tempering, but the surface becomes extremely hard.

Regarding the base structure in Table 1, pearlite is represented by M and P1 martensite is represented by M.

(Structural Photograph) FIG. 2 shows a microscopic structural photograph (Nital liquid corrosion, 400x magnification, hereinafter the same) of the NQl test material in Table 1.

Carbide (white part) is distributed in the pearlite base (black part).

FIG. 3 is a photograph of the structure of Nα2. A nitride compound layer (about 13 μm thick) on the surface and a nitride diffusion layer (about 90 μm thick) below.
μm) is formed, and a network of nitrides can be seen above the diffusion layer. Carbide (white part) is observed in the tempered martensite base (black part) in the lower part of the diffusion layer and the base material below it.

FIG. 4 is a photograph of the structure of Nα3. Carbide (white part) is distributed in the martensite base (black part). Nα
Compared to No. 2, the carbide becomes finer grained due to the influence of WlNO.

[Effects of the Invention] As described above, the vane of the present invention has excellent wear resistance and scuffing resistance, and exhibits excellent performance particularly when used in a compressor that is subjected to a high load.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a compressor using the vane of the present invention. FIGS. 2, 3, and 4 are microscopic metallographic photographs of cast iron materials used in the vane of the present invention.

Claims (2)

[Claims] (1) Component composition in weight%, C: 2.5-3.7%, S
i: 1.0-2.0%, Mn: 0.5-1.0%, Cr
:10~20%, Ni:0.3~0.7%, P:0.3
% or less, S: 0.1% or less, the balance is Fe and unavoidable impurities, and the vane for a compressor is made of a cast iron material in which carbides mainly composed of Cr are uniformly precipitated in a pearlite and/or martensite base. (2) Component composition in weight%, C: 2.5 to 3.7%, S
i: 1.0-2.0%, Mn: 0.5-1.0%, Cr
:10~20%, Ni:0.3~0.7%, and W, M
o, V, Nb, Ta: 1 to 10% of one or more types,
P: 0.3% or less, S: 0.1% or less, the balance consists of Fe and unavoidable impurities, and a compressor made of cast iron material in which carbides mainly composed of Cr are uniformly precipitated in a pearlite and/or martensite base. Vane for use.