JPH0417645A - Fe-base sintered alloy excellent in wear resistance - Google Patents

Abstract

PURPOSE:To provide an Fe-base sintered alloy excellent in wear resistance by uniformly dispersing prescribed percentages of Fe-Mo-Si intermetallic compound with a specific composition into an Fe-C alloy matrix. CONSTITUTION:An Fe-base sintered alloy where 5-30%, by weight, of Fe-Mo-Si ternary-system intermetallic compound having a composition consisting of 35-65% Mo, 5-15% Si, and the balance Fe with inevitable impurities is uniformly dispersed into an alloy matrix having a composition consisting of 0.2-1% C and the balance Fe with inevitanle impurities is prepared. Moreover, it is preferable that about 1-5% Ni and/or about 0.05-0.6% P is further incorporated into the above alloy matrix. Since this sintered alloy shows superior wear resistance owing to the uniform dispersion of the above hard intermetallic compound excellent in adhesive strength to the matrix, this sintered alloy can produce superior properties over a long period even under severe conditions when used for various wear resistant structural members and sliding members.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has excellent wear resistance, and is used, for example, in valve seats and valve guides of automobile internal combustion engines, pantograph sliders in electric cars, and various other sliding parts. The present invention relates to an Fe-based sintered alloy that exhibits excellent performance over a long period of time even under severe conditions when used as a moving member or a wear-resistant member.

[Conventional technology]

Conventionally, various Fe-based sintered alloys have been used to manufacture the above-mentioned various members.

Among these various Fe-based sintered alloys, C:08
~1.5%, Ni: 1.5-4%, Cu: 0.5
-2%, Mo: 2.5-6.5%, with the remainder consisting of Fe and unavoidable impurities, and a structure in which 3-20% Fe-Mo alloy is uniformly dispersed in the base material. C: 0.5 to 2%, Ni: 3 to 2%, as described in the base sintered alloy and JP-A No. 64-15349.
Fe-based sintered bond in which Fe-Mo alloy is uniformly dispersed at a ratio of 3 to 20% in an alloy base having a composition of 14%, Mo: 3 to 14%, and the remainder consisting of Fe and unavoidable impurities. Gold (the above weight% and the below % indicate weight%)
etc. are known.

[Problem to be solved by the invention]

On the other hand, in recent years, automobiles and electric vehicles have become faster and faster, and as a result, the environments in which these structural components such as valve seats, valve guides, and pantograph sliders are used have become increasingly harsh. This requirement may be due to the fact that even higher wear resistance is required, or because the conventional Fe-based sintered alloys mentioned above that make up these various structural members do not have sufficient wear resistance. The current situation is that it is not possible to respond satisfactorily.

[Means to solve the problem]

Therefore, from the above-mentioned viewpoint, the present inventors have developed a conventional F having a structure in which Fe-Mo alloy is dispersed in the above-mentioned base material.
As a result of our research to develop a Fe-based sintered alloy that is even better than the e-based sintered alloy, we have developed M o: 35-60%, Si: 5-15
%, with the remainder consisting of Fe and unavoidable impurities, and has a micro Vickers hardness (MHv) of 70.
Fe-Mo-Si3 with high hardness of 0-1400
When the elementary intermetallic compound is dispersed in the matrix at a ratio of 5 to 30%, preferably with an average particle size of 20 to 50 in, the resulting Fe-based sintered alloy is
The adhesion of the o -Si ternary metal 1uI compound to the above-mentioned substrate is extremely high, and even when exposed to high-temperature combustion gas or high-speed abrasion under arcing, for example, falling off from the substrate is significantly suppressed. As a result, the research results showed that it showed significantly lower wear resistance.

This invention was made based on the above research results, and contains C: 0.2 to 1%, and further contains Ni: 1 to 5% and P 0.05 to 0.6 as necessary. %, the rest is Fe and unavoidable impurities, Mo: 35 to 65%, Si: 5 to 15%, the rest is F having a composition consisting of Fe and inevitable impurities
e -Mo-Si B-based intermetallic compound, 5 to 30
It is characterized by an Fe-based sintered alloy with excellent wear resistance, which is uniformly dispersed at a ratio of 1.5%.

Next, in the Fe-based sintered alloy of the present invention, the reason why the numerical values are limited as described above will be explained.

Composition of A9 alloy base (a) C The C component has the effect of solid solution in the base and improves the strength and hardness of the base, but if its content is less than 0.2%, the desired effect is not achieved. On the other hand, if the content exceeds 1%, the toughness will decrease.
Its content was determined to be 0.2 to 1%.

(b)'Ni The Ni component has the effect of solidly dissolving in the base material and further improving its strength and corrosion resistance, so it is included as necessary, but the content is 1%. If the content is less than 5, the desired effect of improving the above action cannot be obtained;
Even if the content exceeds 96, no further improvement effect was observed due to the above-mentioned action, and the content was determined to be 1 to 5% in consideration of economic efficiency.

(c) P Since the P component has the effect of improving sinterability and thereby contributing to strength improvement, it may be included as necessary, or if its content is less than 0.05%, it may not achieve the desired effect. On the other hand, if the content exceeds 0.6%, embrittlement tendency appears, so the content was reduced to 0.05%.
It was set at ~0.6%.

B. Component composition of intermetallic compound (a) M.

For the Mo component, the hardness of the intermetallic compound is 700 in M Hv.
It has the effect of maintaining a high hardness of ~1400, but if the content is less than 35%, the above-mentioned high hardness cannot be obtained, whereas if the content exceeds 65%, it becomes too hard and increases the aggressiveness of the opponent. Therefore, the content ratio should be set at 35~
It was set at 65%.

(b) The Si St acid component has the effect of dramatically improving the adhesion of the intermetallic compound to the substrate, and therefore, if its content is less than 5%, the desired effect of improving the adhesion cannot be obtained; If the content exceeds 15%, the hardness of the intermetallic compound itself decreases, so the content is set at 5 to 15%.

If the proportion of the C1 intermetallic compound in the base material is less than 5%, the desired wear resistance cannot be secured, while if the proportion exceeds 30%, the aggressiveness of the material increases. The ratio was set at 5-30%.

[Examples] Next, the Fe-based sintered alloy of the present invention will be specifically explained using examples.

As raw material powders, Fe-Mo-Sj 3yc-based intermetallic compound powder and Fe-Mo alloy powder, both produced by the water atomized method and having the average particle size and component composition shown in Table 1, average particle size: 40 blood Fe-P alloy (P:2796 containing) powder, 60 blood F
E powder, carbonyl N1 powder of same 5 blood, and carbon powder of 10 m were prepared, and these raw material powders were blended into the composition shown in Table 1, mixed for 30 minutes with a V-type mixer, and then 7 tons/ The powder compacts are press-molded at a pressure of 1,150 to 1,000 m in vacuum.
By sintering at a predetermined temperature within the range of 220°C for 1.5 hours, a composition that is substantially the same as the blended composition, a theoretical density ratio shown in Table 1, and io+oII
Xl.

Invention FeM sintered alloy 1 with dimensions of mm x 35 mm
-12 and conventional Fe-based sintered alloys 1-12 were manufactured, respectively.

Regarding the present invention and conventional Fe-based sintered alloys obtained as a result, the outer diameter with the rotation axis horizontal: 40 mm x inner diameter: 30 mm
QIIIX Length: 15 mm Heat-treated ring made of FC250 (hardness: HRC50) The Fe-based sintered alloy of the method described above was brought into contact with it horizontally from above, and in this state, a load of 1 kg was applied to the above-mentioned Fe-based sintered alloy. Hang the ring vertically for 15 m.
A wear test was conducted in which the wear depth was measured by measuring the surface roughness after 30 minutes by rotating at a circumferential speed of 1/2.
Shown in the table.

〔Effect of the invention〕

From the results shown in Table 1, the Fe-based sintered alloys 1 to 1 of the present invention
It is clear that all of No. 12 exhibit much superior wear resistance compared to conventional Fe-based sintered alloys No. 1 to 12.

As mentioned above, the FC-based sintered alloy of the present invention is made of a hard Fe-Mo-S that has excellent adhesion to the substrate.
i It exhibits excellent wear resistance due to the uniformly dispersed content of B-based intermetallic compounds, so it can be used as various wear-resistant structural members or sliding members that require even higher wear resistance. It has industrially useful properties such as stable performance over a long period of time.

Claims (4)

[Claims] (1) Add Mo: 35 to 65%, Si: 5 to 15% to an alloy base having a composition of C: 0.2 to 1%, and the remainder consisting of Fe and unavoidable impurities in terms of weight percent. Fe-Mo-Si ternary intermetallic compound containing 5 to 3
Fe with excellent wear resistance, uniformly dispersed at a ratio of 0%
Base sintered alloy. (2) In terms of weight percent, an alloy base containing C: 0.2 to 1%, further Ni: 1 to 5%, and the remainder consisting of Fe and unavoidable impurities, Mo: 35 to 65%, Si: 5 to 15%, and the remainder is Fe and inevitable impurities.
Fe with excellent wear resistance, uniformly dispersed at a ratio of 0%
Base sintered alloy. (3) An alloy base having a composition containing, in weight%, C: 0.2 to 1%, P: 0.05 to 0.6%, and the remainder consisting of Fe and inevitable impurities. A Fe-Mo-Si ternary intermetallic compound containing Mo: 35-65%, Si: 5-15%, and the remainder consisting of Fe and unavoidable impurities is added to
Fe with excellent wear resistance, uniformly dispersed at a ratio of 0%
Base sintered alloy. (4) Contains C: 0.2 to 1% in weight%, and further contains Ni: 1 to 5%, P: 0.05 to 0.6%,
Fe-Mo-Si system containing Mo: 35 to 65%, Si: 5 to 15%, and the remainder having a composition of Fe and unavoidable impurities in an alloy base having a composition of Fe and unavoidable impurities. 5 to 3 ternary intermetallic compounds
Fe with excellent wear resistance, uniformly dispersed at a ratio of 0%
Base sintered alloy.