JPH04189897A - Lubrication pretreatment for hot forging - Google Patents

Abstract

PURPOSE:To improve the hot-forging property (hot-lubricity) by forming a chemical conversion coating on the surface of an Al (alloy) material to be worked and applying an aqueous lubrication treatment liquid to a forging mold to form a lubrication film. CONSTITUTION:A chemical conversion coating composed of aluminum fluoride or calcium aluminate is formed on the surface of an Al (alloy) material to be worked. Separately, a lubricating film is formed on a forging mold by coating the mold with an aqueous lubrication treatment liquid composed of (A) 50-400 g/l of a lubrication compound selected from molybdenum disulfide, graphite, calcium carbonate surface-treated with a silane-coupling agent, boron nitride, fluorinated graphite, talc and stearic acid salt, (B) 0.5-40 g/l of a surfactant, (C) 5-150 gel (in terms of solid) of a binder compound selected from an alkali metal or alkaline-earth metal salt of silicic acid, boric acid and phosphoric acid, a copolymer of maleic anhydride and styrene, etc., PVA, cellulose, etc., (D) a colloidal titanium and (E) water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of lubricating the surfaces of the metal and the die during hot forging of aluminum or aluminum alloy.

[Conventional technology]

Conventionally, when hot forging aluminum or aluminum alloys, lubricating oil, grease, or combinations of these with solid lubricants such as graphite powder or molybdenum disulfide are used. A fine powder mixture consisting of sulfates of alkali metal salts, borates, graphite, and a lubricating agent added if necessary is dispersed in water and then applied to a mold, and then forged. It's flying.

However, oil-based lubricating compositions are thermally unstable and decompose during use, causing echogenic effects on molds and workpieces, as well as the oil contaminating the working environment significantly. There is. In addition, if we consider the cooling performance and workability of the mold, water-based lubrication is suitable, or even better, as the lubrication performance is unstable and often causes problems such as seizure and cracking. There is now a need for a 1iril treatment method that exhibits heat resistance and stable and excellent lubrication performance.

[Problem that the invention seeks to solve]

The present invention was made in order to solve the problems in hot forging aluminum or aluminum alloy using conventional water-based lubricants, and the present invention is to solve the problem of hot forging of aluminum or aluminum alloy using conventional water-based lubricants. Alternatively, a chemical conversion film of carunium aluminate is formed, and then colloidal titanium is added to a water-based lubricating treatment liquid consisting of a lubricating component represented by molybdenum disulfide, carunium stearate, etc., a surfactant, and a binder. It has been discovered that by applying a lubricating film containing 10 ppm or more, superior hot forgeability (hot lubricity) can be obtained than when using a known water-based lubrication treatment liquid. Thus, the lubrication treatment method of the first invention was completed.

As a result of further studies, the inventors of the present invention found that after forming the chemical conversion film on the workpiece, a film of a solid lubricant represented by molybdenum disulfide, graphite, etc. They discovered that hot lubricity could be further improved by the synergistic effect of these films, and completed the second invention.

[Means for solving problems]

That is, the present invention provides the following methods: ``An aluminum fluoride film or a carunium aluminate film is formed as chemical IWlil on the surface of an aluminum or aluminum alloy workpiece, and a mold is coated with molybdenum disulfide, graphite, or silanic acid. carbonate, tungsten disulfide, surface treated with a bling agent,
50 to 400 g/l of one or more lubricating components selected from boron nitride, graphite fluoride, talc, carunium, magnenium, aluminum, and barium salts of stearic acid, and 0.5 to 40 g of a surfactant. /
l, and a binder selected from alkali metal salts and alkaline earth metal salts of silicic acid, boric acid, and phosphoric acid, copolymers of maleic anhydride and styrene or isobutylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, and cellulose. Aluminum or aluminum characterized by forming a lubricating film by applying an aqueous lubrication treatment liquid consisting of 5 to 150 g/l as a solid content of one or more compounds and 10 ppm or more as titanium of colloidal titanium. Lubrication treatment method for alloys and dies before hot forging. ”.

Next, the second invention provides the following methods: ``After forming an aluminum fluoride film or a calcium aluminate film as a chemical conversion film on the surface of the aluminum or aluminum alloy workpiece, graphite, tungsten disulfide and nitride are added on the film. A film of at least one solid lubricant selected from boron is formed on the mold, and the surface of the mold is treated with molybdenum disulfide, graphite, and a silane coupling agent, such as calcium carbonate, tungsten disulfide, boron nitride, and graphite fluoride. 50 to 400 g/l of one or more lubricating components selected from talc, calcium, magnesium, aluminum, and barium salts of stearate, and 0.0 g/l of a surfactant.
5 to 40 g/l, silicic acid, boric acid,
and alkali metal salts and alkaline earth metal salts of phosphoric acid,
5 to 150 g as a solid content of one or more compounds selected from a copolymer of maleic anhydride and styrene or isobutylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, and cellulose.
/l and 10 p p as titanium of colloidal titanium
A water-based lubrication treatment liquid consisting of more than m and water! j! A method for lubricating aluminum or an aluminum alloy before hot forging, which comprises applying a cloth to form a lubricating film. ”.

In the present invention, the chemical conversion coating formed on the surface of the workpiece is an aluminum fluoride coating or a calcium aluminate coating. In the case of a phosphate film, since the hot forging temperature of aluminum is as high as 400 to 500°C, water of crystallization separates from the film and its bonding strength deteriorates, so it cannot be used as a lubricating film for hot forging. The film applied in the present invention does not contain water of crystallization and is stable up to 500°C, so it has good heat resistance up to 500°C. Furthermore, since the film has a barrier effect that prevents direct contact between the workpiece and the mold, it has the role of suppressing seizure.

Furthermore, as shown in the second invention, after forming the chemical conversion film on the surface of the aluminum-based workpiece, a material having a heat resistance of 500° C. or higher, such as graphite, tungsten disulfide, or boron nitride, is further added to the film. By applying a solid lubricant to form a film, the lubricity is further improved. This is because the chemical conversion film has excellent adhesion to the purple metal surface and excellent lubricant film retention.

Next, the lubricant components in the water-based lubrication treatment liquid applied to the mold are as follows:
First, as solid lubricants, molybdenum disulfide, graphite, calcium carbonate surface-treated with a silane coupling agent, tungsten disulfide, boron nitride, graphite fluoride, and talc are preferable in consideration of lubricity and heat resistance. Next, as the metal soap for improving lubricity, calcium, magnesium, aluminum, and barium stearate salts are preferred. More preferably, the metal soap is a wet form obtained by double decomposition method (Japanese Patent Publication No. 60-4568
It is desirable to use the one disclosed in Publication No. 0). One or more of these lubricating components can be arbitrarily selected.
It is contained in the aqueous lubricating treatment liquid in a range of 50 to 400 g/l. If it is less than 50g/l, the formation of a solid lubricant film on the mold tends to be insufficient.On the other hand, if it is added in excess of 400g/l, the lubricating effect will be saturated, and further performance improvement is required. , and the cost of the aqueous lubrication treatment liquid increases, which is not preferable. A more preferable blending range is 150-250g/
It is l.

Next, a surfactant is added to disperse the solid lubricant in water, and although this is not specified in the present invention, examples of nonionic surfactants include polyoxyethylene alkyl ethers and polyethylene alkyl ethers. Examples include oxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan alkyl esters, etc., and anionic ones include fatty acid salts, sulfate ester salts, sulfonates, and phosphate esters. Examples include salts and dithiophosphate salts. Next, examples of cationic surfactants include aliphatic amine salts, quaternary ammonium salts, etc., and examples of amphoteric surfactants include amino acid type and U/Tine type carboxylates, sulfate ester salts, Examples include sulfonate salts and phosphate ester salts. Two surfactants can be arbitrarily selected from the above-mentioned surfactants, and their blending into the aqueous lubrication treatment liquid is approximately 0.
It ranges from 5 to 40 g/l and is usually added in proportion to the amount of solid lubricant. If it is less than 0.5g/1,
The wetting effect on the solid lubricant tends to be insufficient, and the effect is not improved even if it is added in an amount exceeding 40 g/l. The amount of surfactant added to the aqueous lubricant is preferably 45 to 10 g/l.

Next, the binder! Either grafted or organic type is fine.
Specifically, examples of inorganic salts include alkali metal salts or alkaline earth metal salts of silicic acid, boric acid, and phosphoric acid as shown by formulas a to C below.

a, silicate general formula M2O, x S i O2 where M is an alkali metal or alkaline earth metal x:
, i] ~ 5 positive integer Borate HBO, , H, BO, , H2B, ○ ~, HB, O, ,
, H, B, ○1. Alkali metal salts and alkaline earth metal salts C ricinates H,PO,, HPO2, H,P2O, HyuP20ゎ,
HPO3, H, PO,, H,, P, O, and Otsu' polyphosphoric acid, for example, H, P, 0-1H, P, O,, H, P,
Alkali metal salts and alkaline earth metal salts of acids such as Examples include isobutylene copolymer, polyvinyl alcohol, polyvinylhyloritone, polyethylene glycol, and U-cellulose.The amount of one or more compounds selected from the above-mentioned compounds as a binder in the aqueous lubricating treatment liquid. is 5~ as solid content] 5
It is in the range of 0 g/1, and is generally added proportionately depending on the amount of solid lubricant. If it is less than 5g/l, the bonding force of the lubricant film is weak, and on the contrary, if it is 150g/l
Adding a larger amount does not improve the binding effect and increases the viscosity of the water-based lubricant, which is not preferable. If the viscosity becomes high as in 2, the amount of lubricant applied to the mold will increase, and during forging, the excess lubricant will turn into scum and stick to some parts of the mold, causing problems during forging. Undesirable. A more preferable range is 10 to 50 g/l.

Next, colloidal titanium is, for example, a cloudy white liquid obtained by neutralizing a compound of @acid and titanium, or a compound of phosphoric acid and titanium with caustic soda or caustic potassium,
The content of colloidal titanium as titanium in the aqueous lubrication treatment liquid needs to be 10 ppm or more, more preferably 50 ppm or more. When the concentration of colloidal titanium is less than 10 ppm, the effect of improving lubricity performance due to the addition of colloidal titanium is difficult to be clearly recognized, and when it is added at 10 ppm or more, it is confirmed that the lubricity is improved, and the lubricity improves as the titanium concentration increases. However, the present invention does not specify the upper limit concentration, and the SII of water-based lubricants]! ! The upper limit is the highest possible concentration. Furthermore, in the present invention, there is no objection to adding an antifoaming agent or the like to the water-based lubricant.

〔Example〕

EXAMPLES Below, in order to specifically explain the lubrication treatment method for hot forging of the present invention, examples will be given and described together with comparative examples.

The workpiece used was 5056 material with an aluminum base metal.

(Cylinder of 30mmφ x 18~40mm) The pretreatment and lubrication treatment of the workpiece were carried out in the following steps. Nihon Bariki Rising Fine Cleaner 315 30g
/l, 70°C, and pickling was carried out for 15 seconds at room temperature using a mixed solution of 7% nitric acid and 3% hydrofluoric acid.

Also, the aluminum fluoride coating is made of sodium silicofluoride 27.5g/i, zinc fluoride 2. It was treated in a treatment solution containing 1 g/l at 95° C. for 10 minutes to form cedar. Carunium aluminate film has hydroxide power of 9.3g/l
, chloride 362g/l, sodium chloride 14
．． It was formed by treatment at 70° C. for 10 minutes in a treatment solution containing 5 g/l.

Washing with water was carried out for 60 seconds at room temperature with running tap water.

The lubrication treatment after the film treatment includes 160 g/l of at least one solid lubricant selected from graphite, tungsten disulfide, and boron nitride, Ig/l of a surfactant, and 20 g/l of magnesium silicate as a binder. =Water A copolymer of maleic acid and isobutylene was treated in an aqueous lubricant consisting of 1 g/l and water at 80°C for 13 minutes, then air-dried with a hairdryer and coated with a target coating weight of 10 g/m2. Thereafter, after heating in an electric furnace at 450° C. for 2 hours, lubricity was evaluated by a backward perforation extrusion test. The test conditions are (1
) Test equipment MSF200 crank press manufactured by Fukui Machinery Co., Ltd. (2) Processing speed 30 spm (3) Mold punch 20.2 mmφ, 5KD61200
It was heated to 0.degree. C. and 10 cc of the lubricant of the present invention was spray applied.

(4) Mold guide 30 mmφ, SKD] 110
Heat to 0℃ and use the lubricant of the present invention in the same way as punch] Occ
I scrubbed it and applied one coat.

(5) Evaluation was made based on the maximum drilling depth (referred to as "good drilling depth") that could be processed without generating vertical stripes on the inner wall surface of the cup in the punched area.

Table 1 shows the composition of the lubricant treatment source for molds, and Table 2 shows the results of the backward perforation extrusion test of Examples and Comparative Examples.

The lubricant treatment source of the present invention was prepared by mixing and dispersing the morning products shown in Table 1 in a homogenizer at 8000 r, p, m, and 1 hour. In addition, a solid lubricant treatment solution to be applied onto the skin μ was similarly prepared.

As is clear from Table 2, the lubricity of Examples 1 to 17 is significantly improved compared to Comparative Examples 1 to 8.

Note that in Comparative Example 1, no lubricant was applied to the mold.

In Comparative Examples 2 to 4, no chemical conversion coating treatment was applied to the workpiece. In Comparative Example 5, the amount of solid lubricant as a lubricating component was 40g/
It is l. Comparative Examples 6 and 7 do not contain colloidal titanium in the lubricant. On the comparative example day, Vicedar was not blended.

Table 1 &lI Table 2-1 Rear drilling extrusion test results of aqueous lubrication treatment liquid for molds Effects of the invention As explained above, hot forging: By using it repeatedly, seizure will not occur even in hot forging with a large degree of processing, and by using a white solid lubricant film, it is possible to greatly improve the working environment and workability.

Claims (2)

[Claims] (1) An aluminum fluoride film or a calcium aluminate film is formed as a chemical conversion film on the surface of the aluminum or aluminum alloy workpiece, and the mold is surface-treated with molybdenum disulfide, graphite, or a silane coupling agent. One or more lubricating components selected from calcium, tungsten disulfide, boron nitride, graphite fluoride, talc, calcium stearate, magnesium, aluminum, and barium salts.
~400 g/l, 0.5-40 g/l of surfactant, and alkali metal and alkaline earth metal salts of silicic acid, boric acid, and phosphoric acid as binders, a combination of maleic anhydride and styrene or isobutylene. Water-based lubrication treatment consisting of 5 to 150 g/l as a solid content of one or more compounds selected from polymers, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, and cellulose, 10 ppm or more as titanium of colloidal titanium, and water. A method for lubricating aluminum or aluminum alloys and molds before hot forging, which comprises applying a liquid to form a lubricating film. (2) After forming an aluminum fluoride film or a calcium aluminate film as a chemical conversion film on the surface of an aluminum or aluminum alloy workpiece, at least one layer selected from graphite, tungsten disulfide, and boron nitride is applied on the film. A film of various types of solid lubricants is formed, and the mold is coated with molybdenum disulfide, graphite, calcium carbonate surface treated with a silane coupling agent, tungsten disulfide, boron nitride, graphite fluoride,
50 to 400 g/l of one or more lubricating components selected from talc, calcium, magnesium, aluminum, and barium salts of stearate, 0.5 to 40 g/l of a surfactant, and silicic acid as a binder. , boric acid, alkali metal salts and alkaline earth metal salts of phosphoric acid, copolymers of maleic anhydride and styrene or isobutylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, and cellulose. 5 to 150 as the solid content of the compound
g/l and 10ppm as titanium in colloidal titanium.
A method for lubricating aluminum or aluminum alloys and molds before hot forging, which comprises applying a water-based lubricating liquid consisting of the above and water to form a lubricating film.