JPS5822359A - Iron base sintered alloy for structural member of fuel supply apparatus - Google Patents

Abstract

PURPOSE:To obtain a sintered alloy for the structural member of a fuel supply apparatus having anti-wear property, compatibility and corrosion resistance even if used in supplying low grade gasoline or alcohol containing gasoline, by containing a specific amount of C, Cr and one or more of P, B, Si in steel. CONSTITUTION:The structural member of a fuel supply apparatus has a composition consisting of, on the wt% basis, 0.5-3.5C, 5-35 Cr, 0.05-3 Mn, one or more of 0.03-3 P, B, Si and the remainder of Fe and inevitable impurities. By employing this composition, carbide is fundamentally dispersed and precipitated throughout a Fe base alloy material as well as a structure wherein Cr is dissolved in the material to form a solid solution is obtained and, therefore, anti- wear property, compatibility and corrosion resistance are enhanced. In addition, one or more of 0.5-10 Mo, W, one or more of 0.5-10 Ni, Co, Cu are pref. contained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an Fe-based sintered alloy for structural members of fuel supply devices having excellent wear resistance, conformability, and corrosion resistance.

Conventionally, diaphragm pumps and vane-type feed pumps, for example, have been generally known as fuel supply devices, and these fuel supply devices have structural members such as housings and rotors, and furthermore, pumps are provided at predetermined intervals along the outer circumferential surface of the rotor. It is also well known that the fitted rollers, blades, etc. are made of heat-treated bearing steel.

By the way, in recent years, due to the deterioration of the oil situation, low-quality gasoline, alcohol-containing gasoline, and even alcohol have come to be used as fuel, and as a result, the above-mentioned fuel supply devices have come to be used to supply these fuels. However, in this case, the above-mentioned bearing steel structural members have poor mutual compatibility and poor wear resistance, and furthermore, the moisture contained in alcohol or the pH of low-quality gasoline
Corrosion was caused by acidification caused by the drop.

Therefore, from the above-mentioned viewpoint, the present inventors have developed a fuel supply device that exhibits excellent wear resistance, conformability, and corrosion resistance even when used for supplying fuels such as low-quality gasoline, alcohol-containing gasoline, and even alcohol. As a result of conducting research on the structural members of the fuel supply system, we found that the structural members of the fuel supply system were
:0.5-3.5%.

Cr: 5-35%, Mn: 0.05-3%, P,'
One or more of B and Sl: 0.03
-3%, and if necessary, one or two of MO and W: 0.5-10%, Ni, Co.

and one or more of Cu: 0.5~1O
%, one of Nb, Ta, Ti, and Zr
When the seed layer is composed of an Fe-based sintered alloy having a composition (by weight %) containing two or more kinds of 0.05 to 10% and the remainder consisting of Fe and unavoidable impurities, the resulting structural member will be as described above. Depending on the composition, carbides are basically dispersed and precipitated in the Fe-based alloy matrix, and Cr is solidly dissolved in the matrix, resulting in excellent wear resistance, conformability, and corrosion resistance. This invention was made based on the above knowledge, and the reason why the component composition range was limited to the above general range will be explained below.

(a) C The C component is dissolved in the base material to strengthen it, and
Cr, Mo gW and N contained as necessary
b, Ta, Ti, and Zr to form carbides and have the effect of improving wear resistance, but if the content is less than 0.5%, the desired effect cannot be obtained; If the content exceeds 3.5%, the amount of carbide precipitated will be too large, resulting in embrittlement and damage to the mating member, so the content should be reduced to 0.5 to 3%.
．． It was set at 5%.

(b) Cr The Cr component is dissolved in the base material to improve corrosion resistance, strengthen it, and further combine with C to form Cr carbide with high hardness, thereby improving wear resistance. However, if the content is less than 5%, the desired effect cannot be obtained, while if the content exceeds 35%, the base material becomes brittle and the wear resistance deteriorates. Therefore, the content was determined to be 5 to 35 chi.

(c) P, B, and Sl These components not only solidly dissolve in the base material and strengthen it, thereby improving wear resistance, but also react with Fe during sintering to form a liquid phase. The sintering that occurs and activates sintering, thereby densifying the sintered body and stabilizing carbides, has the effect of improving corrosion resistance, but the content is 0.03%.
If the content is less than 3%, the desired effect cannot be obtained; on the other hand, if the content exceeds 3%, the corrosion resistance will deteriorate again and embrittlement will become significant.
It is set at 0.3% to 3%.

(d) Mn Mn has the effect of forming a solid solution in the base material and improving toughness as well as conformability and corrosion resistance.
If the content is less than 0.05%, the desired effect cannot be obtained, while if the content exceeds 3%, the crystal grains will become coarser, resulting in a decrease in strength and corrosion resistance. Since the content will be reduced to 0.
It was decided that it would be Section 05-3.

(e) Mo and W These components form a solid solution in the base material and strengthen it, as well as combine with C to form carbide and improve wear resistance. When used under such conditions, it may be included as necessary, but if the content is 0.
If it is less than 5%, the desired effect of improving the above action cannot be obtained,
On the other hand, if the content exceeds 10%, damage to the mating member will increase, so the content was set at 0.5 to 10%.

(f) Ni, -, Co, and Cu These components have the effect of further strengthening the base material, further improving the compatibility with the mating material, and further improving the corrosion resistance against the fuel used, so they are particularly recommended. It is included as necessary when these characteristics are required, but if the content is 0.5
If the content is less than 10%, the desired improvement effect on the above properties cannot be obtained, and on the other hand, if the content exceeds 10%, no further improvement effect will be obtained.

The person in charge was appointed as the person in charge.

(g) Nb, Ta, Ti, and Zr These components have a strong affinity with C, so they combine with C to form carbides with high hardness, and also form double carbides together with carbide-forming components such as Cr. These properties form a stronger bond between the carbide as the dispersed phase and the matrix as the binder phase, thereby further improving wear resistance and further improving corrosion resistance against low-quality fuel. It is contained as needed when required, but if the content is less than 0.05%, the desired improvement effect on the above properties will not be seen, while if it is contained in excess of 10%, damage to the mating member may occur. Since it becomes large, its content is reduced to 0.
．． It was set at 0.05 to 10%.

The Fe-based sintered alloy of the present invention preferably has a theoretical density ratio of 85 coefficients or more, which is 85%.
This is because if the theoretical density ratio is less than that, when used for supplying fuel such as degraded gasoline or alcohol, corrosion resistance and conformability will deteriorate.

Next, the Fe-based sintered alloy of the present invention will be explained using examples and comparing with comparative examples.

Examples of raw material powders include Fe powder with a particle size of -100 mesh and Fe-Cr alloy (all formed by water injection method).
Cr: 3B%) powder, Fe-Cr-Ta alloy (C
r: 21%, Ta: 11%) powder, same Fe-Cr-
Zr alloy (containing Cr: 21%, 'Zr: 11%) powder,
The same Fe-Cr alloy (Cr: 66% content) powder, the same Fe-
Mn alloy (containing 5% Mn near) powder, Fe-3i gold (
Fe-B alloy (P: 27%) powder, Fe-B alloy (B: 20%)
% content) powder, the same Fe-3i alloy (Si: 42% content)
Powder, Fe-Nb alloy (containing 6s% Nb) powder, Fe-Ta alloy (containing 67% Ta) powder, Fe-T
i alloy (containing 2% T1Nia) powder, same Fe-Zr alloy (
Zr: 'i'o% content) powder was prepared, and scaly graphite powder with particle size knee 100mesh 1 particle size: -100
Mesh electrolytic Cu powder, MO powder each having an average particle size: 3 μm.

Prepare W powder, Ni powder, and C○ powder, blend these raw powders into the composition shown in Table 1, add 0.7% zinc stearate as a lubricant, mix, and make this mixed powder. was formed into a green compact at a pressure of 5 tons/ca,
Then, the green compact is heated in vacuum at a temperature of 1100 to 12
After sintering at a predetermined temperature of 20°C for 60 minutes and quenching from a temperature of 950 to 1000°C, the temperature:
Sintered alloys 1 to 45 of the present invention and comparative sintered alloys 1 to 1o, which have substantially the same final component composition as the blended composition, were obtained by performing a tempering treatment at a temperature of 500 to 540°C for 60 minutes. were manufactured respectively.

Comparative sintered alloys 1-10 all have compositions in which the content of one of the constituent components (indicated with an asterisk in Table 1) is outside the scope of this invention. It is.

Next, the resulting sintered materials 1 to 45 of the present invention and comparative sintered materials 1 to 10 were measured for theoretical density fart and Vickers hardness, and were also subjected to a wear resistance test and a corrosion resistance test.

The wear resistance test was conducted using each of the above sintered alloys with a diameter of 28 mm.
A rotor for a motor-type fuel pump with dimensions of φ x length: 5 + + + m and six grooves formed at regular intervals along the outer peripheral surface in parallel to the axial direction was created, and this rotor was hardened. T (RC: JIS-3US with '54
When installed in the 430 housing, H2O:
2.0%, alcohol; immersed in gasoline containing 12%, surface pressure: 4 to 9/cd, rotation speed: 300 Or,
The tests were conducted by operating the test tube under conditions of p and m for 500 hours, and after the operation, measuring the average depth of wear on the sliding surfaces of the rotor and housing (mating member).

Corrosion resistance tests were conducted by immersion in alcohol containing 10% H2O for 100 hours and in degraded gasoline for 50 hours.
In the former alcohol immersion test, the state of rust formation was observed. If there was no rust at all, mark ○, if there was slight rust, mark Δ, if there was significant rust, mark X. Further, in the latter gasoline immersion test, the state of discoloration was observed, and no discoloration was evaluated with a 0 mark, slight discoloration with a Δ mark, and cases with significant discoloration with an X mark. These results are also shown in Table 1.

From the results shown in Table 1, even if the content of any of the constituent components falls outside the range of the present invention, the wear resistance, conformability, and It is clear that the sintered materials 1 to 45 of the present invention all have excellent wear resistance, conformability, and corrosion resistance, whereas at least one property of corrosion resistance is inferior. It is.

As mentioned above, the sintered alloy of the present invention has excellent wear resistance, conformability, and corrosion resistance, so it can be used not only for fuels such as ordinary gasoline and diesel oil, but also for degraded gasoline and H20. It has industrially useful properties such as exhibiting excellent performance over an extremely long period of time when used in the manufacture of structural members for fuel supply devices for fuels such as alcohol-containing gasoline and alcohol-containing gasoline and alcohol.

Applicant: Mitsubishi Metals Corporation Agent Tomi 1) Kazuo

Claims (8)

[Claims] (1) C: 0.5-3.5%, Cr: 5-35%
, Mn: 0.05 to 3%, one or more of P, B, and Si: 0.03 to 3%, the remainder being Fe, and unavoidable impurities (wt%). ) for a structural member of a fuel supply device, characterized by having
Base sintered alloy. (2) C: 0.5-3.5%, Cr: 5-35%
, Mn: 0.05 to 3%, one or more of P, B, and Si: 0.03 to 3%,
More M. Fe for structural members of fuel supply devices, characterized in that it contains 0.5 to 10% of one or two of W and W, with the remainder consisting of Fe and unavoidable impurities (weight percent). Base sintered alloy. (3) C: 0.5-3.5%, Cr:
5-35%, Mn: 0.05-3CH, P, B,
and one or more of Si: 0.03~
Contains 3% of Ni. One or more of Co and Cu 0.5
An Fe-based sintered alloy for a structural member of a fuel supply device, characterized in that the Fe-based sintered alloy has a composition (the above weight %) containing Fe and unavoidable impurities. (4) C: 0.5-, -3.5%, Cr: 5-3
5%, Mn: 0.05-3%, P, B, and Sl
One or more of: 0.03 to 3%, and further Nb. One or more of Ta, Ti, and Zr:
An Fe-based sintered alloy for a structural member of a fuel supply device, characterized in that the Fe-based sintered alloy contains 0.05 to 10%, with the remainder consisting of Fe and unavoidable impurities. (5) C: 0.5-3.5'%, Cr: 5
~35%, Mn: 0.05-3%, P, B, and S
Contains one or more of: 0.03 to 3, and further contains M. and one or two of W: 0.5 to 10 chi;
A fuel containing 0.5 to 10% of one or more of Ni, Co, and Cu, with the balance consisting of Fe and unavoidable impurities (wt%) Fe-based sintered alloy for structural members of supply equipment. (6) C: 0.5~3.5%, Cr: 5~
35%, Mn: 0.05-3%, one or more of P, B, and Sl: 0.03-3%,
More M. and one or two of W: 0.5 to 10%,
A fuel containing one or more of Nb, Ta, Ti, and Zr: 0.05 to 10%, with the remainder consisting of Fe and unavoidable impurities (weight %) Fe-based sintered alloy for structural members of supply equipment. (7) C: 0.5~3.5%, Cr: 5~
35%, Mn: 0.05-3%, P, B, and S
One or more of i: 0.03 to 3, and further Ni. One or more of Co and Cu20.5
-10%, one or more of Nb, Ta, Ti, and Zr: 0.05 to 10%, and the remainder is Fe and unavoidable impurities (wt%).
) for a structural member of a fuel supply device. (8) C: 0.5-3.5%, Cr-5-35
%, Mn: 0.05 to 3 H, one or more of P, B, and Sl: 0.03 to 3 H,
More M. and one or two of W -0.5~lO%,
One or more of Ni, Co, and Cu:
0.5-10%, one or more of Nb, Ta, Ti, and Zr: 0.05-10%, and the remainder is Fe and unavoidable impurities (weight ratio) An Fe-based sintered alloy for a structural member of a fuel supply device, comprising: