JPS60187699A - Composite iron plating having superior wear resistance - Google Patents

Abstract

PURPOSE:To improve the wear and seizing resistances of iron plating by dispersing and depositing chromium carbide and silicon carbide each having a prescribed particle size in the iron plating in a prescribed ratio. CONSTITUTION:Hard particles of chromium carbide having <=10mum particle size and silicon carbide having <=3mum particle size are dispersed in an iron plating soln., and plating is carried out to form composite iron plating contg. hard particles by 5-25wt% of the amount of iron. The weight ratio of chromium carbide/ silicon carbide is 20/80-80/20. The composite iron plating has improved wear and seizing resistances.

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a sliding member with excellent wear resistance and seizure resistance, particularly suitable for piston rings, cylinders, and vane materials of internal combustion engines. The present invention relates to composite iron plating, which is a coated film.

[Prior art]

Conventionally, surface treatments such as hard chrome plating and thermal spraying have been used to impart wear and seizure resistance to parts that require wear resistance and seizure resistance, such as sliding members such as piston rings and cylinders in internal combustion engines. ing.

However, taking piston rings as an example, hard chrome plating is no longer able to cope with the deterioration of sliding conditions caused by higher speeds and higher outputs of engines, and thermal spraying has its own wear and seizure resistance. Although there are some excellent ones available, they tend to cause a lot of wear on the mating cylinder, so they are not yet widely used.

In addition, in recent years, attempts have been made to use aluminum for cylinders in order to reduce the weight of engines. A lot of wear, especially 1t
It cannot be used because it has poor fi adhesion, thermal spraying tends to cause apressive wear, and mating cylinder wear becomes significant, making it unusable.

Recently, composite iron plating dispersed in SLA 1 has been proposed as a countermeasure (for example, Japanese Patent Publication No. 57-5845
Public No. 9 @). However, in the case of composite iron plating in which sIc is dispersed, although it has the effect of improving its own wear resistance and seizure resistance, it has not completely solved the problem of increased wear of the mating material.

Under these circumstances, it is desired to establish a surface treatment technology that can improve the wear resistance and seizure resistance of the material itself and also reduce the wear of the mating material.

[Object of the present invention]

The purpose of the present invention, in order to meet the above-mentioned needs, is to provide a material that is not only superior in wear resistance and seizure resistance, but also reduces wear on the mating material.

[Configuration of the present invention]

In order to achieve the above object, the present invention is characterized in that hard particles of chromium carbide and silicon carbide are both dispersed and precipitated in iron plating, thereby improving its own wear resistance and seizure resistance. It is possible to make it equal to or higher than that in the case of silicon carbide alone dispersion analysis liver, and to greatly reduce the wear of the mating material.

[Specific configuration of the present invention]

In the present invention, the reason why chromium carbide and silicon carbide are dispersed and precipitated during iron plating is as follows. That is, as seen in the wear test results (Fig. 3) using a reciprocating friction tester schematically shown in Fig. 1, 810, CR, C, , Tie, TI was used as a composite material to be dispersed in iron plating.
We conducted a wear test using 40 g of hard particles of N, Cr2O3, and A as candidates (hereinafter referred to as Experiment 1), and found that even when using a 17% Si aluminum alloy (/590), which is equivalent to a cylinder, gray cast iron (Fe12) In the case of a partner, when the above-mentioned hard particles are dispersed alone in iron plating, those with excellent wear resistance tend to have more wear on the other, and those with less wear on the other have poor wear resistance on their own. , and it is not possible to find something that can satisfy both parties. On the other hand,
A composite material that combines a material with excellent wear resistance and a material with low wear resistance tends to compensate for the weaknesses of both. In particular, the combination of Or3c and slc reduces both its own wear and the wear of its partner than when each is dispersed in iron plating alone, and a remarkable synergistic effect can be obtained. Therefore, in the present invention, chromium carbide and silicon carbide are dispersed and precipitated.

In Fig. 1, 1 is a bottle (upper specimen), 2 is a flat plate (lower specimen (mate material)), 3 is a hydraulic cylinder, 4 is a load cell,
5 is a driving source. The wear lid was evaluated based on the wear scar diameters a and b of the bottle (upper specimen 1) shown in Figure 2 (A) (the scar diameter a in the sliding direction indicated by the arrow α in Figure 1, and the scar diameter in the direction perpendicular to it). trace diameter b)
For the flat plate shown in FIG. 2 (B) (opposite material>>2vc), measurements were taken at all five step differences using a roughness meter running in the direction of the arrow, and the average value was displayed.

The test conditions for Experiment 1 are as follows.

1. Test sample ■ Lower specimen (counterpart material) (2 in Figure 1): 17% S1 aluminum alloy: HRB70FO25 (J-Ko S G55
01 (1976) Gray cast iron): HRB 96 70
72) Carbon tool steel Hardness HRB9B Shape = 8φ
I made it thicker and finished it with 18R spherical finish.

The plating conditions at that time were as follows.

Bath (#i11 fluoride bath) composition: Ferrous fluoride (F13 (BF4): 50f/ferrous sulfate (FeSO4-7H20): 500f/ammonium chloride (NH,Ol): 30?/l Bit inhibitor (sodium lauryl sulfate): 2ml/bath
Temperature: 65°C Current density: 4 A/dm”, time: 4.5
Hr composite material: 809/l, 810, cr, ○
* #TIC#TiN, 0120g, A120B
, 8i0+TiN (50:50), ○rlo, +Ti
N (50:50).

SiO+0r3(1!1 (50:50)Table 1 Figure 6 Plating characteristics of sample material Conditioning: 2 to 9fX100cpmX5 minutes test: 1
0 to 9f x 600cpm x 50 minutes Lubricating oil 2 SAI [
Equivalent to 110W, α2 cc/min mist spray,
The composite ratio of chromium carbide and silicon carbide is 20:8 by weight.
The reason why setting the ratio to 80:20 is a preferred embodiment is because the results of the reciprocating friction test (hereinafter referred to as Experiment 2) shown in Figure 4 are as follows.
This is because when the ratio of orges is less than 20%, the wear of the opposing material increases rapidly, and when it exceeds 80%, the wear of the own material increases. The sample used for the test has a mating material of 17%81 aluminum alloy, and the pin base material is sx5.
The shape and finish were the same as in Experiment 1, and the plating conditions were also W.
It is the same as the one in the Js diagram. The details of the plating are shown in Table 2.
Figure 4: The reason why it is preferable to set the total compounding ratio of chromium carbide and silicon carbide to 5 to 25 wt% of the iron plating is shown in Figure 5. Reciprocating friction test (hereinafter referred to as
As is clear from the results (Experiment 3), when S wt% is less than 25 wt%, the wear of the plate itself is insufficient, and when it exceeds 25 wt%, the plating film becomes hard and brittle, causing hard particles to fall off and accelerating the wear of the other side. Not only that, but it also causes more wear and tear on itself. In addition, considering the wear of itself and the other party, a range of 10 to 20 wt% is more desirable. The sample used for the test was made of 171Si aluminum alloy material, and the shape and finish were the same as in Experiments 1 and 2. The pin (top specimen) was the same as the base material, shape, finish, and plating conditions of Experiment 1.2. The plating contents are shown in Table 3. The wear test conditions are the same as those in Experiments 1 and 2.
The reason why it is preferable to set the particle size of chromium carbide to 10 μm or less and the silicon carbide particle size to 3 μm or less is as follows.

As a result of performing composite iron plating and reciprocating friction test (hereinafter referred to as Experiment 4) with various grain sizes of Cr5a* and sla, as shown in Fig. 6, the grain size of ar, c, was 10μ. This is because when the particle size of SaC exceeds 3μ gold, the wear of the mating material increases rapidly. When considering both its own wear and the wear of the mating material, the particle size of 0r302 is 1
~5μ, and the particle size of sea is more preferably in the range of 0.6 to 1μ. The sample used for the test had a mating material of 174Si aluminum alloy, a pin base material Hsx5, and the shape and finishing method were the same as in Experiments 1 to 3. Table 4 Figure 6 Plating contents of sample material Next, the method for performing composite iron plating of the present invention will be explained.

The composite iron plating of the present invention is produced by Dojo's Misaki 1 fluoridation bath (optimum pH
A3-4) as well as ferrous sulfate baths (optimum pH 2-2.
5), chloride bath (optimum pH 0.2 or less), sulfamic acid bath (optimum pH 2 to 2.5), Guandaloy bath (trade name, etc.) can also be used (in addition, in each bath, the pH above the above The liquid will oxidize and become unusable, and if it is less than that, problems such as rough fitting and poor dispersion will occur.) The electrode is preferably made of low carbon steel with few impurities.
5S41 material (J Engineering 8G5101 (1976) - rolled steel material for membrane structures) can also be used.In addition, when the bath temperature becomes low, the plating hardness increases and cracks are likely to appear, and when the bath temperature becomes too high, It is preferable to carry out the process at around 65°C, as electrolytic erosion of the workpiece and plating roughness are likely to occur.Furthermore, if the current density is too high, the dispersion concentration will decrease.
Since problems such as jumps may occur, 4 to 5 A/a- is appropriate.

〔Example〕

Examples of the present invention will be described below.

Upper specimen 1 (φB×2
! The end face of the IL, 8 to -5, pin) was processed into an 18H spherical surface, coated with composite iron plating according to the present invention, α2 thickness, and then polished into an 18R spherical surface. The plating thickness after polishing was 115 m, and the hardness was Hv563. The details of the plating at that time are as follows.

Bath composition: Ferrous fluoride (Fe (BF4)3):
50 f/ 1st iron (FeSO4-7H,O)
: 500 f/1 ammonium chloride (NH40t)
: 30? / 1 bath temperature: 65°C Nfffb density: 4 A/dm” 1 hour: 4.5H
r composite material: cr, a, 409/l, 81Cj 4
The maximum particle size of cr3c used as the 09/l composite material is 5 μ (average particle size 3 μ), and the maximum particle size of SiO is 1 μ (average particle size 0.6 μ), and approximately 50
:50, and the total composite rate was 12 wt%.

As a comparison material, hard chromium plating and Fe-Cr alloy spraying by plasma spraying were applied to the end face of a φ8×23 pin, which was machined into a 18 mm spherical surface and used for testing. The hardness of the hard chromium plating was HV958, and the hardness of the Fe-0riu plating was Hv786.

For the above six types of pins, 17% S1 is used as the mating material.
The aluminum alloy material and the cast iron material of Fc25 were processed into a flat plate (lower specimen) 2 of 7OL x 17W x 7 using the testing machine shown in Fig. 1, the test surface was puff-polished, and a reciprocating friction test was performed. The results are shown in Figure 7. The test conditions were the same as in Experiment 1 above.

As is clear from FIG. 7, the composite iron plating according to the present invention has a lower resistance even when used with a 17% S1 aluminum alloy material than the comparative hard metal plating and Fe-Cr plasma sprayed material. FC! Even when used with No. 25 cast iron material, not only the wear on itself but also the wear on the other party is reduced. In particular, the sliding surface condition is 17% S1. When mating with aluminum alloy material, hard chrome plating has many sliding scratches due to scuff ink. In contrast, the composite iron plating according to the present invention creates a very smooth friction surface for both itself and the mating material, whereas the silicon is excavated and the particles fall off from the sprayed surface, accelerating wear. It can be seen that it has excellent properties as a friction material.

In addition, FIG. 8(A) shows 1 of the above composite iron plating of the present invention.
A micrograph at 00x magnification is shown. In FIG. 8(A), 11 is a base material (EIK-5), 12 is a pure iron layer, 13 is a composite iron plating layer, and 14 is an embedded resin. .

FIG. 8(B) shows the composite iron plating layer 15 in FIG. 8(A).
It is a micrograph of 0500 times.

When the pure iron layer 12 in FIG. 8(A) is subjected to composite plating,
It is produced by plating without stirring the liquid, and the composite iron plating is used as the base material (in this case, 5K-
If 5) is applied directly, poor adhesion will occur, so it is created for the purpose of eliminating this.

Further, the embedded resin 14 in the figure is used for taking cross-sectional photographs.

In Figure 8 (B), what looks like a slightly larger circle is Cr3C.
What looks like 2. is 810.

[Effects of the present invention]

As described above, in the composite iron plating of the present invention, the composite O is chromium carbide + silicon carbide, and preferably the composite ratio is Fe
By specifying the ratio and particle size in the plating, it can be determined that the ba-in which has less wear on itself than in conventional Togane plating using a single composite material has a lot of wear on the other side, and when there is little wear on the other side, the wear on itself has increased. Eliminates the drawback that there are many, single attachment '10
It has a synergistic effect of reducing both its own wear and the wear of its counterpart than those obtained by the above method, making it extremely useful as a sliding member and of great value in the warping industry.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the nominal reciprocating friction tester used in the wear test of the present invention, Figure 2 is a diagram showing the method for evaluating the amount of wear,
Figure 5 is a graph showing the results of a wear test conducted to check the wear resistance of various composite materials in iron plating, Figure 4 is ar3
Figure 5 is a graph showing the wear test results tested by changing the compounding ratio of 0r302+SiO and SLC.
The figure shows Or, 0. Figure 7 is a graph showing the results of a comparative wear test between the composite iron plating according to the present invention, conventional hard chrome plating, and plasma sprayed material. FIG. 8 is a cross-sectional photograph showing the metal structure of the composite iron plating according to the present invention. Agent 1) Akira's agent Ryo Hagiwara - Procedural amendment June 1980/Evening 1] Commissioner of the Patent Office Kazuo Wakasugi 1. Tenant's representation < 1980 A9.1 Tomi'j - Request number 41958 No. 2. Invention 0 name, iii, @15 sex, 9 iron 3, oil stopping name ゛1 kidney'1. Relationship with 'l'l'if'l 1 out 1 da 1 ゛f people 1i 1'li Yaesu-chome 9-9-4, Chuo-ku, Tokyo, Agent fl ``su1 Higashi 1j District 1, Toranomon-1, Minato-ku 'l]16
Total 2 China 17g Nomon E Dai Ill Building Tun + f, T, ('
, 1 (14゜1894 Mr. Otsu I)゛Ri 1: L71
79+ 1 111 Akira (1 other person) (1) “Detailed description of the invention” column in the specification (2) Figures
Contents of the surface 8 amendment 1 (1) The description ``cylinder'' in the first line of page 2 of the specification is corrected to ``cylinder (including cylinder block, cylinder lychee), or rotary pump or rotary compressor.'' (2) On the 9th page, line 6 from the bottom, the statement ``own wear and tear'' has been revised to read ``own wear resistance''. (3) The description "max particle size" in the upper column of Table 4 on page 16 is corrected to "maximum particle size Ql)". (4) The description "Fe-Cr thermal spraying" in the first line of page 16 is corrected to "Fe-Cr thermal spraying layer." (5) Before the statement "Composite ratio" on the 3rd line of page 18 (add /C "for each of the above two lines"). (6) "Ratio in plating" on the 6th line of page 18 of the same The statement ``total coalescence ratio J during plating is revised to IE. If plating is applied to the sliding part side, it will have an extremely useful effect.'' (8) Figures 2 (B) and 3 of the drawings are corrected as shown in the attached sheet. Figure 2 (B)

Claims (3)

[Claims] (1) A composite iron plating with excellent wear resistance characterized by fully dispersed hard particles of chromium carbide and silicon carbide precipitated in the iron plating. (2) The composite ratio of chromium carbide and silicon carbide is 20:80 to 80:20 by weight, and the total of hard particles of chromium carbide and silicon carbide is 5 to 25 wt% relative to the iron plating.
A composite iron plating with excellent wear resistance according to claim (1), which has a gold % characteristic. (3) The wear resistance according to claim 1 or 2, where the particle size of chromium carbide is 10μ or less and the particle size of silicon carbide is 3μ or less. Excellent composite iron plating.