JP4508343B2 - Oil-based lubricant - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the provision of an oil-based lubricant that is used when a hard metal material is molded by hot extrusion forging at a high mold temperature.
[0002]
[Prior art]
Generally, oil-based lubricants used for hot extrusion forging are prepared by dissolving an extreme pressure additive (metal soap, etc.) in mineral oil and mixing and suspending it with a solid lubricant such as graphite. .
[0003]
[Problems to be solved by the invention]
The present inventor has found that such oil-based lubricants tend to cause wear of the mold during hot extrusion forging of materials of high hardness such as Ni alloy and Ti alloy, and the extrusion load during forging tends to increase. Thus, it has been found that the wear of the die of the forging is also increased.
[0004]
The present invention provides an oil-based lubricant that can be used in a high-temperature mold used for hot extrusion forging of a material with high hardness such as a Ni alloy or a Ti alloy, and has excellent thermal stability and coating film formability. This is the issue.
[0005]
[Means for Solving the Problems]
The present invention is an oil-based lubricant that is supplied into a high-temperature mold of 300 to 600 ° C. in order to hot-extrusion forge a material of high hardness material, and in 100 parts by weight of the oil-based lubricant, The present invention relates to an oil-based lubricant containing 25 to 35 parts by weight of a solid lubricant, 5 to 15 parts by weight of a nonionic activator and 15 to 25 parts by weight of a modified silicone oil. The material of the material is Ni alloy or Ti alloy, the solid lubricant is graphite powder, the graphite powder is a mixture of low particle size graphite and high particle size graphite, and the low particle size graphite has an average particle diameter of 1 to 5 μm. And the low particle size graphite has a particle size distribution containing 5% by weight or less of graphite particles having a particle size of 0.5 μm or less and graphite particles having a particle size of 10 μm or more, Granular graphite has a purity of 99.5% or more The high particle size graphite has an average particle size of 10 to 50 μm, and the high particle size graphite has 5 wt% each of graphite particles having a particle size of 5 μm or less and graphite particles having a particle size of 100 μm or more. % Of the particle size distribution, the high particle size graphite has a purity of 95% or more, and the low particle size graphite and the high particle size graphite are in a weight ratio of 2: 1 to 1: 1. characterized in that it is mixed, but according to the oil type lubricant.
[0006]
In order to obtain an oil-based lubricant that can prevent wear of a mold, suppress an extrusion load during forging, and prevent wear of a forged product, the present inventor made and studied various oil-based lubricants.
[0007]
As a result, when the conventional oil-based lubricant is supplied into a high-temperature mold, the inventor has poor dispersibility and adhesiveness of the solid lubricant, and the solid lubricant does not stay in the mold and lubrication is possible. It has been found that a sufficient coating film of a solid lubricant cannot be formed in the necessary mold.
[0008]
In the case where the present inventor hot forges a material of high hardness using a high temperature mold of 300 to 600 ° C., in the conventional hot extrusion forging, a stable coating film of a solid lubricant is subjected to such a high temperature. It was elucidated that the wear of the mold increases, the extrusion load during forging increases, and the wear of the forged mold increases.
[0009]
Based on this knowledge, the present inventor conducted further studies in order to obtain an oil-based lubricant that is excellent in thermal stability and film-forming property even in a high-temperature mold used for forging Ni alloy, Ti alloy and the like.
[0010]
As a result, the inventor of the present invention significantly improved the film-forming property of the oil-based lubricant by uniformly dispersing the heat-resistant solid lubricant in the dispersion medium containing the nonionic activator and the modified silicone oil. However, the present inventors have found that a solid lubricant film can be sufficiently formed even in a high-temperature mold, and reached the present invention.
[0011]
According to the inventor's research, 25 to 35 parts by weight of a solid lubricant, 5 to 15 parts by weight of a nonionic activator and 15 to 25 parts by weight of a modified silicone oil in 100 parts by weight of an oily lubricant, It has been found that the dispersibility and adhesiveness of the solid lubricant are remarkably improved by mixing.
[0012]
If the solid lubricant is less than 25 parts by weight, the film thickness of the lubricant is too thin, causing film breakage and increasing the extrusion load. On the other hand, when a solid lubricant exceeding 35 parts by weight is mixed, the viscosity is remarkably increased, the flow of the paint in the mold is deteriorated, and the lubricant cannot be supplied.
[0013]
A nonionic activator of less than 5 parts by weight has a poor dispersion effect, and a uniform lubricating coating film is not formed. On the other hand, even when a nonionic activator exceeding 15 parts by weight is added, the state of dispersion does not improve, and no improvement in coating properties is observed.
[0014]
The modified silicone oil of less than 15 parts by weight cannot improve the lubricity and heat resistance of the base oil, the oil component evaporates too quickly, and the supply of the lubricant does not reach deeper. On the other hand, the modified silicone oil exceeding 25 parts by weight does not improve the heat resistance of the base oil, slows the evaporation of the oil, flows too much lubricant, and cannot supply the lubricant to the necessary part.
[0015]
The oil-based lubricant with improved dispersibility and adhesiveness of such a solid lubricant has the separation of the solid lubricant and the dispersion medium suppressed, and the coating film of the solid lubricant maintains an appropriate thickness. Can do.
[0016]
According to the present invention, in high-temperature hot extrusion forging, a coating film of a heat-resistant solid lubricant such as graphite is uniformly formed in a mold, and such solid lubricant is uniformly Ni alloy, Ti alloy or the like. Since the surface of the high hardness material is covered, the wear of the mold is prevented, the extrusion load during forging can be kept low, and the wear of the forged product can be remarkably reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described.
The present invention solves the problem of coating properties of conventional oil-based lubricants, and particularly provides an oil-based lubricant used when molding a material of high hardness at a high mold temperature. is there.
[0018]
In the present invention, in order to reliably supply the lubricant to the mold surface during the hot extrusion forging of such a high-hardness material, a solid lubricant such as graphite is used in the oil with excellent thermal stability. The solid lubricant is dispersed and uniformly supplied into the mold, and a stable coating film of the solid lubricant is formed between the mold and the material of high hardness material.
[0019]
The oil-based lubricant of the present invention is supplied to a high-temperature mold (maintained at 300 to 600 ° C.) by a spray or shower method, and lubricity is particularly required due to its good lubricity and adhesive strength. A coating film of a solid lubricant such as 40 to 120 μm of graphite can be formed on the mold surface.
[0020]
The coating film of such a solid lubricant reduces the extrusion load when molding a material with high hardness, reduces the wear of the forging, prevents the mold from being worn, and prevents the mold from being worn. The mold life can be improved.
[0021]
As the material of the high hardness material according to the present invention, various hard materials that are hot forged in a high temperature mold are used. Examples of such high hardness materials include Ni alloys and Ti alloys.
[0022]
As the solid lubricant according to the present invention, various materials can be used as long as they have heat resistance, are uniformly dispersed in the oil-based lubricant, and the formability of the solid lubricant coating is not impaired.
[0023]
As such a solid lubricant, boron nitride, graphite powder or the like can be used. Natural graphite powder can be used as the graphite powder.
[0024]
In the present invention, such a solid lubricant is dispersed in a dispersion medium containing a modified silicone oil and a nonionic activator. The dispersion ratio of the solid lubricant is 25 to 35 parts by weight in 100 parts by weight of the oil-based lubricant.
[0025]
In the present invention, a nonionic activator and a modified silicone oil are contained in the oil lubricant in order to improve the dispersibility of the oil lubricant and the coating film formability.
[0026]
Various nonionic activators can be used, and examples thereof include alkylbenzene sulfonates, polyoxyethylene alkyl ethers, polyoxyesylene alkylphenol ethers, sorbitan acid esters, and the like.
[0027]
Various modified silicone oils can be used, and examples thereof include dimethylpolysiloxane, alkyl-modified silicone, and methylphenyl silicone.
[0028]
The nonionic activator according to the present invention is contained in 5 to 15 parts by weight in 100 parts by weight of an oil-based lubricant.
[0029]
The modified silicone oil according to the present invention is contained in 15 to 25 parts by weight in 100 parts by weight of an oil-based lubricant.
[0030]
Further, in the present invention, it is preferable to use a mixture of low particle size graphite and high particle size graphite as the graphite powder of the solid lubricant. This is because, in such a mixture of graphite powders, high particle size graphite increases heat resistance, and low particle size graphite increases the formability of the coating film.
[0031]
Two or more types of graphite powders having different average particle diameters can be used in the graphite powder mixture. In the present invention, for example, a mixture of low particle size graphite having an average particle size of 1 to 5 μm and high particle size graphite having an average particle size of 10 to 50 μm can be used.
[0032]
Further, in the present invention, in the graphite powder mixture, the low particle size graphite having an average particle size of 1 to 5 μm contains 5 graphite particles having a particle size of 0.5 μm or less and 5 graphite particles having a particle size of 10 μm or more. The high particle size graphite having a particle size distribution containing not more than% by weight, having a purity of not less than 99.5%, and having an average particle size of 10 to 50 μm is composed of graphite particles having a particle size of 5 μm or less and 100 μm. It has a particle size distribution containing 5% by weight or less of graphite particles having the above particle diameter, and has a purity of 95% or more. The weight ratio of the low particle size graphite and the high particle size graphite is It is preferable to be mixed at 2: 1 to 1: 1.
[0033]
When there are many fine particle (0.5 μm) portions of low particle size graphite, oxidation consumption is quick and lubricity does not continue. In order to form a close-packed coating film, graphite having a sharp particle size distribution is optimal. Outside the range of 2: 1 to 1: 1, close packing is impossible. Since the low particle size graphite is surrounded around the high particle size graphite, the lower the particle size graphite, the better the lubricity. By using 99.5% or more high-purity graphite, it is possible to prevent impairing lubricity due to impurities.
[0034]
Furthermore, in the present invention, the natural graphite powder can be packed most closely by blending with the particle size, and the denseness of the graphite coating can be improved. Such a solid lubricant is particularly useful for maintaining lubricity in a temperature range of 200 ° C. or higher after the oil in the oil-based lubricant has evaporated.
[0035]
In the present invention, the oil-based lubricant contains commonly used components such as adhesives, dietary oils, mineral oils and the like in a range that does not adversely affect the dispersibility and film-forming properties of the solid lubricant. Can do.
[0036]
The oil-based lubricant of the present invention is a soft heat-resistant film with moderate adhesion due to the addition of a dispersant, the introduction of a dispersion technique using a disperser, and the addition of an adhesive that improves adhesive strength at high temperatures. Thus, it is possible to form a coating film of a solid lubricant having excellent followability to a forged new surface and having a stable friction coefficient.
[0037]
【Example】
The present invention will be described based on examples and comparative examples with reference to the drawings.
FIG. 1 is a drawing-substituting photograph showing the film forming property on a horizontal plane. FIG. 2 is an explanatory diagram of FIG. FIG. 3 is a drawing-substituting photograph showing the film-forming property at an angle of 30 °. FIG. 4 is an explanatory diagram of FIG. FIG. 5 is a side view of the reciprocating lubrication tester. FIG. 6 is a graph showing the friction coefficient of the oil-based lubricant. FIG. 7 is a front view of a high-hardness material used in the example of the present invention. FIG. 8 is a front view of the forging manufactured in the example of the present invention.
[0038]
Oil type lubricant of Example <br/> this example,
(A) Particle size cloth having an average particle size in the range of 1 to 5 μm, particles having a particle size of 0.5 μm or less are 5% by weight or less, and particles having a particle size of 10 μm or more are 5% by weight or less Natural graphite powder having a purity of 99.5% or more having an average particle diameter of 10 to 50 μm, particles having a particle diameter of 5 μm or less and 5% by weight or less, and a particle diameter of 100 μm or more 25 to 35 parts by weight of a mixture of particles having a particle size distribution of 5% by weight or less and graphite powder having a purity of 95% or more in a ratio of 3: 2.
(B) 15-25 parts by weight of refined vegetable oil,
(C) 5 to 10 parts by weight of petroleum rosin,
(D) 15 to 25 parts by weight of modified silicone oil,
(E) 5 to 15 parts by weight of nonionic active agent (stops spreading),
(F) The refined mineral oil is composed of 10 to 20 parts by weight.
[0039]
As described above, in the oily lubricant of this example, refined vegetable oil and silicon oil as a synthetic oil were blended in order to improve the lubricity and heat resistance of the oil. In order to maintain lubricity particularly in the temperature range of 200 ° C. or more after the oil has evaporated, natural graphite powder was blended in a particle size and closely packed to improve the denseness of the graphite coating. In particular, in order to form a lubricating film on the mold surface (longitudinal surface of 30 to 60 mm) at a high temperature (300 to 600 ° C.) that requires lubrication, a nonionic activator is blended to change the dispersion state of the graphite particles. Improved, petroleum rosin was used as an adhesive.
[0040]
Comparative Example The oil-based lubricant of this example is 5 to 10 parts by weight of an extreme pressure additive, 5 to 10 parts by weight of metal soap, and 25 to 25 parts of graphite powder having an average particle diameter of 30 μm with respect to 100 parts by weight of refined mineral oil. 30 parts by weight of lubricant was mixed.
[0041]
Coating film formation test The oil-based lubricants of Examples and Comparative Examples were dropped (1 cc) on the surface of an iron plate at a temperature of 500C set at an angle of 30 °. The results are shown in FIGS. FIGS. 1 and 2 show the drop after dropping on a horizontal iron plate, and FIGS. 3 and 4 show the drop after dropping on a 30 ° angle iron plate.
[0042]
As shown in FIGS. 1 to 4, the oil-based lubricant 1 of the developed product of the example did not spread and showed a flow of 45 mm. Moreover, since the oil-based lubricant 1 of the developed product of the example does not separate the solid lubricant and the oil component and does not flow more than necessary, the appropriate thickness of the coating film was maintained. On the other hand, as shown in FIGS. 1 to 4, the conventional oil-based lubricant 2 of the comparative example spreads significantly, flows 100 mm, and an appropriate thickness of the coating film is not maintained.
[0043]
Reciprocating lubrication test For the oil-based lubricants of Examples and Comparative Examples, the friction coefficient at a temperature of 50 to 600C was measured by a reciprocating lubrication tester shown in Fig. 5. As shown in FIG. 5, the reciprocating lubrication testing machine 3 applies an oil-based lubricant to be tested to the sliding surface 6 between the steel plate 4 and the aluminum rod 5, and under a predetermined load 7, The friction coefficient of the oil-based lubricant is measured with the spring balance 8. Although not shown, a heater for controlling the steel plate 4 to a predetermined temperature is provided under the steel plate 4.
[0044]
As shown in FIG. 6, the oil lubricant of the example forms a heat-resistant soft coating film, and since this coating film has appropriate adhesion, it has a friction compared to the oil lubricant of the comparative example. It can be seen that the coefficient is extremely low and the followability to the forged new surface is excellent.
[0045]
Production of forged product Using the oil-based lubricants of Examples and Comparative Examples, a forged product of a stepped shaft as shown in Fig. 8 is formed from a round bar-like material with high hardness as shown in Fig. 7. Manufactured.
[0046]
Manufacturing conditions are
Press used: Knuckle press 400t,
Work material: Titanium alloy, heat-resistant steel, etc.
Extrusion conditions: billet heating temperature, 900-1200 ° C,
Mold temperature: 400-600 ° C
Lubricant supply amount: 1 to 3 cc / time.
[0047]
With the oil-based lubricant of the example, a stepped shaft could be produced without problems. On the other hand, seizure occurred in the oilse lubricant of the comparative example.
[0048]
【The invention's effect】
According to the oil-based lubricant of the present invention, in high-temperature hot extrusion forging, a coating film of a heat-resistant solid lubricant such as graphite is uniformly formed in the mold, and the solid lubricant is uniformly Ni alloy. Since the surface of a high-hardness material such as Ti alloy is covered, the wear of the mold can be prevented, the extrusion load during forging can be kept low, and the wear of the forged product can be significantly reduced.
[Brief description of the drawings]
FIG. 1 is a drawing-substituting photograph showing the film-forming property on a horizontal plane.
FIG. 2 is an explanatory diagram of FIG. 1;
FIG. 3 is a drawing-substituting photograph showing the film-forming property at an angle of 30 °.
FIG. 4 is an explanatory diagram of FIG. 3;
FIG. 5 is a side view of a reciprocating lubrication tester.
FIG. 6 is a graph showing a friction coefficient of an oil lubricant.
FIG. 7 is a front view of a high hardness material used in an example of the present invention.
FIG. 8 is a front view of a forged product manufactured in an example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Oil-based lubricant of Example 2 Oil-based lubricant of Comparative Example 3 Reciprocating lubrication testing machine 4 Steel plate 5 Aluminum rod 6 Sliding surface 7 Load 8 Spring balance

Claims (1)

In order to hot extrude and forge a material having high hardness, it is an oil-based lubricant supplied in a high-temperature mold of 300 to 600 ° C., and 25 to 35 weight in 100 parts by weight of the oil-based lubricant. Part of solid lubricant, 5 to 15 parts by weight of nonionic activator and 15 to 25 parts by weight of modified silicone oil, the material of the high hardness material is Ni alloy or Ti alloy, and the solid lubricant The agent is graphite powder, the graphite powder is a mixture of low particle size graphite and high particle size graphite, the low particle size graphite has an average particle diameter of 1 to 5 μm, and the low particle size graphite is 0.5 μm has a particle size distribution containing less of the particle diameter of the above graphite particles and 10μm particle size and graphite particles child 5 wt% or less, the low particle size graphite has a purity of 99.5% The high-grain graphite is an average of 10 to 50 μm The high particle size graphite has a particle size distribution containing 5% by weight or less each of graphite particles having a particle size of 5 μm or less and graphite particles having a particle size of 100 μm or more; An oil-based lubricant, wherein the granular graphite has a purity of 95% or more, and the low granular graphite and the high granular graphite are mixed in a weight ratio of 2: 1 to 1: 1.

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