JPH0285338A - Iron-based sintered sliding material - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application in Ti Industry) The present invention relates to a wear-resistant iron-based sintered sliding material for engine cylinder liners, bearings, etc. during high-speed oil lubrication.

(Prior Art) Conventionally, in the case of wear-resistant cast iron, a Fe-C-P-based stegate structure is precipitated to impart wear resistance.

In a sintered member to which 0.7% or more of the P component is added, steadite appears as a liquid phase at the Fe powder particle interface during sintering, resulting in a member precipitated in a net shape. (Problem to be solved by Invention C) In the conventional technology, when casting wear-resistant cast iron, i
The upper limit of the amount of Fe-C and -P that can be added is 0.7%, considering quality stability. In addition, sintered materials containing 0.7% or more of P have the disadvantage that steadite precipitates in the form of a net, resulting in a decrease in toughness and making them undesirable as sliding materials. Generally, the limit pv value for sliding materials is 4000 (
kg/cm-m/5ec) or more is actually considered preferable.

(Means for Solving the Problems) The present invention has been made to solve the problems in the above-mentioned conventional technology, and includes a weight ratio of Ni: Q, 2 to 4%, Cr: 0.5 to 3. %, M
o: Alloy steel powder containing one or more selected from 0.05 to 2% in a total amount of 0.1 to 5%, with the remainder substantially consisting of Fe, graphite and phosphorus alloy powder, and as necessary. A11: Mix pure iron powder and other alloy powder, and make CO18~1.4% by weight.
, p:o, 6 to 1.0% is sintered, and then subjected to solution heat treatment at 850°C to tooo°C, and the precipitated steadite is spheroidized. It is made of bonded and sliding material to achieve the purpose.

(For f-ya) When using the previous 3-self configuration, it is possible to add a P component exceeding the upper limit of the P component in casting, and by solution heat treating the steadite precipitated in a net shape, the steadite can be made into a base material. In order to prevent a decrease in toughness, some spherical steadite remains in the solid solution, and the limit Pv
We aimed to improve the quality of the product. The reason for limiting the ingredients in the claim is N.
i: 0.2%, Cr: 0.5%, Mo: 0.0
If it is less than 5%, the hardening effect on the Fe-based material is small and it cannot be used as a wear-resistant material. Ni: 4%, Cr:
3% +Mo: This is because if it exceeds 2%, there is no cost advantage. Moreover, if C: 0.8% and PEoJ% or less, Fe-c-p steadite does not precipitate, and C: 1
．． 4%, P: At 1.0% or more, I appears during sintering.
This is because the e-CP liquid phase amount becomes too large and the shape cannot be maintained.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

The component composition shown in Example 1 in Table 1 was held at 1100°C for 1 hour for sintering, then held at 950°C for 1.5 hours for solution heat treatment, and then held at 600°C for 1 hour. The hardness of the fired crystal obtained by tempering heat treatment is Hv3.
24, the limit Pv value is 6000 ((kg/cm”)・(
m/sec) l. In addition, as a comparison IF'll shown in Table 1 for comparison with the first example, a sintered crystal with the same component composition and sintering conditions as the first example and without solution heat treatment and tempering heat treatment was prepared. The hardness of
v (s 37, but the limit Pv value is aoo.

((kg/can'), (m/sec) l, it was not possible to obtain a low value for practical use. Figure 2 shows the nickel content of the fired crystal according to Comparative Example 1.
FIG. 2 is a diagram showing a state in which steadite is precipitated in a net shape and is not spheroidized.

Next, as a second example in Table 1, the composition was slightly different from the first example, and the sintered crystal obtained by solution heat treatment in the same manner as the first example had a hardness of Hv358 and a limit of Pv. The value is 5500 (kg/cm"-m/5ec), and FIG. 1 is a photograph showing the structure of the fired crystal according to the first example, in which spheroidized spheroidal crystals can be seen.

Table 2 In addition, in order to compare with the second example, as a comparative example 2 shown in Table 1, the component composition and sintering conditions were the same as the second example,
The hardness of the sintered crystal without solution heat treatment is Hv3.
09, but the limit Pv value was 3000 (kg/cm")
-m/5ec), only a value that could not be practically used was obtained. Note that the limit Pv value is a value determined under the conditions shown in Table 2.

(Effects of the Invention) As detailed above, in the case of the present invention, a large amount of stegate is precipitated in the fired crystal in the form of a net by adding more P than in the cast product, but the solution heat treatment removes the stegate from the base material. It can be made into a solid solution and left partially spheroidized. Therefore, the abrasion resistance of the sintered crystal is improved due to the large amount of steadite structure, and it is possible to prevent a decrease in toughness due to the precipitation of steadite in the form of a net. Obtainable.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a microstructure photograph of the sintered crystal in the first example of the present invention, and Fig. 2 is a schematic diagram showing the mwL of the sintered crystal in Comparative Example 1 of the first example. ... Steadite 2 ... Martensite + Barley 3 ... Void

Claims (1)

[Claims] Weight ratio: Ni: 0.2-4%, Cr: 0.5-3%, M
o: Alloy steel powder containing one or more selected from 0.05 to 2% in a total amount of 0.1 to 5%, with the remainder substantially consisting of Fe, graphite and phosphorus alloy powder, and as necessary. If pure iron powder and other alloy powder are mixed, the weight ratio is C: 0.8 to 1.4%, P
: After sintering a sintered member consisting of 0.6 to 1.0%, 8
An iron-based sintered sliding material characterized by subjecting the precipitated steadite to spheroidization by subjecting it to solution heat treatment at 50°C to 1000°C.