JPS6011100B2 - Sintered alloy with excellent wear resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a sliding member with excellent dust resistance and machinability using a powder metallurgy method.

Competitive alloys have excellent composite properties and have excellent abrasion resistance due to the dispersion of hard components with excellent dust resistance into the matrix and the simultaneous inclusion of lubricating low melting point metals, low melting point glasses, sulfur compounds, etc. It is possible to impart properties and processability at the same time.

Based on this idea, the present invention aims to provide a sliding material that is inexpensive and has excellent wear resistance and machinability.

First, to outline the manufacturing method, iron powder is mixed with -150 mesh Fe-Mo and Cr-Mo-Ni, which have a microhardness of Pickers 400 or higher, as hard phase components.
Now, Mo-Ni alloy powder or carbide powder is
r: 0.2~5%, Ni: 0.5~10%, Mo: 4~
12%, C: within the range of 0.2 to 2%, further add and blend 0.2 to 10% of calcium fluoride or barium fluoride, and after mixing press molding, 15% in a reducing atmosphere at 1000 to 1250 ° C. Obtained by curing for ~60 minutes.

Among the constituent components, chromium is Fe-〇 or Cr-Mo-
It is added in the form of Ni alloy powder and diffuses into the surrounding iron base of the ferrite structure during competition, contributing to strengthening the matrix and improving heat resistance and oxidation resistance. This effect is insufficient when the amount added is less than 0.2% at the final Ct%.
% or more, the generation of lubricating oxides of Co and Mo, which will be described later, is suppressed, so the amount of Cd is 0 in the final composition.
．． It is preferable to adjust it to a range of 2 to 5%.

Nickel strengthens ferrite and improves the grade of the matrix.If the amount added is less than 0.5%, the effect is small;
Even if it is added in the above amount, the effect remains the same; on the other hand, if it is too large, austenite will remain partially, which will have an undesirable effect on accuracy and strength, so it is preferably in the range of 0.5 to 10%.

Mo is partly Fe-Mo, partly Cr-Mo-Ni, Mo
-Ni is added in the form of alloy powder, mainly in the following 3. perform one function. '11 During sintering, a part of the material diffuses into the iron base, improving the heat resistance of the base.

■ A part of it remains undiffused as an alloy phase and plays the role of improving magic resistance as a hard phase.

{31 A lubricating oxide in the form of MOO3 is formed in the heat generated during sliding or in a high-temperature atmosphere, improving seizure resistance.

The blending ratio of Fe-Mo and Ni-Mo or Ni-Mo-Cr powder is preferably about 1:1.

If the final Mo% is 4% or less, the above-mentioned function will not be performed sufficiently, which is not preferable. Moreover, even if it exceeds 12%, the effect will not be much improved, so if economic efficiency is considered, a range of 4 to 12% is practical. Carbon melts into iron and strengthens ferrite, while some precipitates as cementite, which improves magic resistance,
Contributes to improving heat resistance.

If the amount is less than 0.4%, the effect of strengthening ferrite and improving the bonito resistance of the base due to cementite precipitation will be small, and if it is more than 2%, the formation of knotwork-like cementite particles will increase, causing material deterioration. A range of .4 to 2% is suitable.

Calcium fluoride and barium fluoride are added as lubricating elements, which prevent metal adhesion in high-temperature atmospheres, improve seizure resistance, and improve workability.

The decomposition temperatures of ursium fluoride and barium fluoride are stable up to high temperatures of 137 needles and 1280 o'clock, respectively.
If the competitive temperature is 1250°C or lower, it will not decompose and disappear when scaled.

Therefore, the lubricating properties are stable from room temperature to high temperatures of around 700°C, and the material of the present invention also exhibits excellent wear resistance.
Addition amount of calcium fluoride or barium fluoride is 0.2
If it is less than 0.2%, the effect of improving the seizure resistance will not be sufficient, and if it is more than 10%, the strength will decrease significantly.
A preferable addition range is 10% to 10%. This will be described in more detail in Examples below.

Example -325 mesh carbon powder and nickel powder and -150 mesh
Mesh of Fe-60%Mo and Ni-30%Mo-1
0% Cr or Ni-50% Mo alloy powder, -250
Mix calcium fluoride or barium fluoride mesh powder and -100 mesh fake fog iron powder in the following composition ratio, compression mold to a density of 85 to 86%, and then phosphorize at a temperature of 1100 oo (hydrogen atmosphere) for 30 minutes. did.

The material thus obtained was investigated for mechanical properties and tested for wear resistance and workability. The numbers in the composition table below indicate weight %, and Fe is the balance. ■ F
e-0. De-4Wo-2Ni-IC song Fe-1-9
Cr-Mother M.

-8Ni-IC)Fe-3Cr-lamo-1■Ni-
IC■ Fe-5Cr-lamo-IONi-IC[E
'Fe-1.9Cr-mother enemy. 18Ni-○-2C■
Fe-1.9Cr-aMo-8Ni-1. &■ Fe-
1-5Cr-disturbance. -mother Ni-IC-○-5CaF2 plates Fe-1.9Cr1mother-phrase Ni-IC-2CaF
2(1) Fe-1.5Cr-consist. -8Ni-IC-8
CaF20) Fe-1.9Cr-1 mother enemy. 18Ni-IC
- shows the mechanical properties of each sample of Sagi F2 in Table 1. The Okoshi type wear test described below was conducted on the samples A to J in Table 1 above.

The test conditions are as follows: '1' Test load 2.2k9 '21 Friction speed 4/sec '3' Friction distance 200 [41 No lubrication (dry) '5) Mating material JISSUH inspection (hardness HRc35)
In addition, Cu-Cr-Mo alloy cast iron/high speed steel F was used as a comparison material.
e-target r-state i-ya o-3W-IC (bran bond 1), F
e-2 to r-1 side i-0. -IC-tsubob (grandson joint metal 2
) were selected and tested at the same time.

The results are shown in Table 2. As shown in the examples in Table 2 and above, the material of the present invention exceeds cast iron, high-speed steel, and heat-resistant alloys containing lead, which are known to have better heat resistance than conventional materials. Demonstrated resistance to magic.

This is believed to be due to the fact that the material of the present invention is composed of a hard phase with high wear resistance and lubricity, and a fluoride compound as a lubricating element.

Claims (1)

[Claims] 1% by weight: Ni: 0.5-10%, Cr: 0.2-5
%, Mo: 4-12%, C: 0.2-2.0%, the balance essentially consists of iron, 20-100 μ of Fe-Mo and N
Hard particles of i-Mo-Cr or Fe-Mo and Ni-M
A total of 5 to 3 o hard particles are present in the base of the ferrite structure.
A sintered alloy with excellent wear resistance characterized by 0% dispersion. 2 The hard particle composition to be dispersed has a Mo content of 50 to 70%
Fe-Mo, Mo content 20-50%, Cr content 5
~20% Ni-Mo-Cr, Mo content 20-50
% Ni-Mo according to claim 1, wherein the sintered alloy has excellent wear resistance. 3 Weight% Ni: 0.5-10%, Cr: 0.2-5
%, Mo: 4-12%, C: 0.2-2.0%, 0.2
~10% of the fluorinated compound, such as calcium or barium fluoride, with the remainder consisting essentially of iron;
100μ Fe-Mo and Ni-Mo-Cr hard particles,
Or a sintered alloy with excellent wear resistance, characterized in that hard particles of Fe-Mo and Ni-Mo are dispersed in a total of 5 to 30% in a base of ferrite structure. 4 The hard particle composition to be dispersed has a Mo content of 50 to 70%
Fe-Mo, Mo content 20-50%, Cr content 5
~20% Ni-Mo-Cr, Mo content 20-50%
The sintered alloy with excellent wear resistance according to claim 3, characterized in that the sintered alloy is Ni-Mo.