DE1594414B1 - Metal working lubricants - Google Patents

Description

The invention relates to water, bound phate, tetrasodium pyrophosphate, sodium metaphos

soluble oil and a complexing agent for phat, sodium hexametaphosphate, sodium tripoly-

Inorganic hardness existing lubricants, for phosphate and the corresponding potassium and

Machining of magnesium metal and aluminum ammonium salts and mixtures thereof selected in such a way

metal in the same rolling mill. 5 that the uncomplexed hardness in the solution

In the following description and in the reference to a concentration of 25 to 400 parts per Proverbs are brought magnesium and alloys, the million, calculated as calcium carbonate contain at least 70 percent by weight magnesium. The lubricant becomes successful in rolling referred to as magnesium metal. Likewise are made of magnesium metal and / or aluminum metal Aluminum and its alloys used at least io the same rolling mill. The received Contains 70 percent by weight aluminum, the following rolled sheet has a satisfactory surface finish referred to as aluminum metal. look on, the emulsion is stable and has a

When trying magnesium metal and aluminum - great service life.

To roll metal on the same mill to rolled magnesium or all alloys on magnesium sheet or to rolled plates, difficulties occurred on the basis or aluminum or all alloys. It has been customary to use an aluminum-based lubricant which served both to cool the rolls of the improved emulsion lubricant composition and to lubricate the rolls while hot-rolling in the present invention. It is true that the metal ran through the rolling mill. In the case of magnesium usually hot-rolled, the present metal has been used as a lubricant, an oil or an aqueous method, but is not limited to the hot-rolling solution of one or more polyglycols, particularly not in the case of aluminum metal. In the case of aluminum, an oil-in-die oil-in-water emulsion was used as the lubricant , which is the case with the usual λ water emulsion. So far, rolling practice has been used for many metals, but it has not succeeded in using magnesium metals from a commercial preparation known as "soluble oil-in-water emulsions satisfactory". Soluble oils are to be rolled hot from a sheet metal. If you tried to use a light hydrocarbon oil, ζ. For example, to use a petroleum oil of the type suitable for magnesium metal in the whale with a viscosity of about 40 to 200 Sayboltzen of aluminum metal, there was a pronounced tendency for the aluminum sheet to be seen and / or nonionic for seconds at 37.8 ° C, one or more anions Emulsifiers, a formation of undesirable surface discoloration. 30 Bactericidal, such as the sodium salt of α-phenylphenol, In addition, more commonly used a high pressure lubricant such as butyl stearate and oil-in-water emulsions were combined with alternating whale water. Using the high pressure smear of magnesium and aluminum medium usually makes up 0.5 to 10 percent of the volume of the polyvalent metal cations of both the magnesium of the soluble oil. Usually 3 to 15 percent by weight of the emulsifying agent, based on that of the emulsion, is added to the emulsion. The weight of the oil used to make the bound, solvent-like contaminated emulsion becomes unstable and borrowed oil is used.

causes stronger corrosion of steel rollers. Typical anionic oil-in-water emulsifiers. The corrosion products result in them being used in an amount which sticks to the magnesium metal on the roll. In addition, 40 emulsification of the light oil is sufficient, the higher corrosion products and small steel alkylbenzenesulfonates are released, with the higher alkyl group leaving bits off the roller and having at least 8 carbon atoms in the upper, ζ. Β.
surface of the magnesium sheet embedded. A magnesium metal sheet treated in this way r π r π cn \ τ Λ is therefore much an- C ₁₂ H ₂₅ C _e H ₄ i> U ₃ JNa. | more due to corrosion. Further difficulties 45 Other anionic emulsifiers include the formation of fats when stray oils are made from such alkyl sulfates as
hydraulic device and the roller _{bearings,, Λ} "
which get into the emulsion, in the presence of the CH ₃ (CH ₂ J ₁₀ CH ₂ UoU ₃ JNa,
additional hardness are not emulsified. Free, the sulfonated fatty amides, such as
non-emulsified oil on the surface of the rolled 50 " _mwrn , _n " _cr . _ΛΤ
Sheet metal, however, tends to _{produce c 17} H ₃₃ CUJN (CH ₃ ,) C ₂ H ₄ & u ₃ JNa,
Surface discoloration during the subsequent and the alkali metal salts of long-chain sulfonated heat treatment. The free oil also creates fatty acids. The alkali metal salts or triethanol often an undesirable sliding of the workpiece in amine soaps. These substances are generally usable in the same way as the rolls of the rolling mill, and to the extent that they are used.

Reduction made per pass Typical oil-in-water lubricant emulsions

can is significantly reduced. In addition, they contain 1 to 10% by weight of such

the continued increase in hardness in the oil-in-bound soluble oil, or the equivalent thereof.

Water emulsion may be gradual. In general, the concentration of soluble

Separation of the emulsion. 60 oil 3 to 7 percent by weight.

The above disadvantages are overcome by the invention according to the invention in the oil-in-water. The invention consists in a lubricating emulsion complexing agents used for the Medium composition for machining magne- inorganic hardness consists of one or more siummetall and aluminummetall, which from water, especially selected inorganic phosphate-1 up to 10 percent by weight of a bound, soluble compound listed above. It is being oiled and a certain amount of a complex that these compounds take the existing there is an educational agent for the inorganic hardness. or enter the aqueous lubricant emulsion AIs Complexing agents will effectively isolate trisodium salts from polyvalent metal cations.

3 4

This prevents such cations from creating a reservoir from which the lubricant can be returned directly

Impair the effect of the emulsifying agent. Apart from being returned to the rolling mill, the necessary

inhibit the selected complexing agents have pumps and the associated pipelines,

the corrosion attack on the ferrous metals during the circulation of the invention standing rolling mills. 5 emulsion it is usually cheap, but not essential

Generally, an addition of 0.05 to borrowed, mill scale, abraded steel-0.35 percent by weight of one or more of the selected from the roller, magnesium metal chips or phosphate salts to the emulsion is sufficient when these aluminum chips and all other fragments are first in use is taken. This amount should normally be filtered out in order to maintain a permanent emulsion, which is large enough to preserve the existing non-io and _{to avoid an impairment of the surface hardness, calculated as CaCO 3} , on the good of the rolled metal,
a concentration in the range of 25 to 400 parts das using the one per million of the present invention. If magnesium metal rolled from the emulsion emulsion is light, practically more hardness is absorbed, one examines the free of surface damage and shows good corrosive emulsion periodically to determine the degree of hardness, 15 ion resistance. Likewise, an agent rolled with the required amount of complexing twisting of the emulsion according to the invention is then added to make the concentration of aluminum metal bright and clean, shows a hardness equal to the non-complexed hardness again to 25 to moderate appearance and is practically free from surface Set 400 parts per million. discoloration of the surface. Common oil-in-water emulsions,

It would be very desirable to increase the concentration of the 20

to reduce free hardness to practically zero, both len phosphate compounds according to the invention modi-

from the standpoint of emulsion stability as well as being verified, show very substantial stability

Corrosion inhibition, however, this is not achieved during a long service life and

because foaming problems occur when steel mills do not attack. In addition, the

the non-complex-bound hardness on a very good filterability of the emulsion, for example by a

wrestling degree is reduced. If necessary, each diatomaceous earth filter, significantly improved,

but as much complexing agent is added, the invention is therefore particularly advantageous

that the non-complex-bound hardness on less part, because here to disperse the emulsion no

than 25 parts per million and the soft or deionized water is required. the

Foaming can then be prevented by using the 30 emulsion from ordinary tap water

Emulsion up to 2 percent by weight of a defoaming or city water can be produced, which is mostly

are added. has a certain degree of hardness. To the harshness too

In another embodiment of the invention, a larger amount of the

the useful life of the oil-in-water complexing agent is added. The inventive

Emulsion also through the use of additional emulsions keep the stability in counter-

Lich emulsifiers of the type listed above wait for concentrations of the complex-bound

long. Such additives are periodically pre-hardness in an amount of 4000 to 5000 parts per

taken comfortably at the same time with the addition of a million.

further complexing agent for the inorganic The following example further illustrates the invention. Hardness. These additions of emulsifiers are special

this is advantageous as it emulsifies rapidly, for example
Tramp oil or stray oil, which its

Finds way into the emulsion, surrender. The additives A number of experiments were carried out in order to

can be done in any conventional manner, e.g. B. by the suitability of the composition according to the invention

Addition in the solid or pure state or as conical when rolling magnesium sheet. In

centered aqueous solution and mixing with the cir- in each case, billets from a magnesium

culminating lubricants. base alloy of the ASTM designation AZ 31 B with

When the rolling process is carried out, it becomes 7.6 × 15.25 × 1.27 cm in size in a furnace Billets or the plate made of magnesium metal or heated to about 482 ° C and then directly on one Aluminum metal usually hot rolled directly from a hot 50 small laboratory mill. Everyone furnace brought into the rolling mill. The lubricant billet was used in six consecutive cycles sprayed on the rolls of the rolling mill and went through the mill to a thickness of about flows down over the entire set of rollers. That decreased .61 cm. The rolling mill was polished with Spraying of the lubricant continues when steel rollers of 8 inches in diameter are fitted, the metal gets on the rollers and persists so- 55 and the rollers were at a temperature of is rolled for a long time. The temperature of the rollers and, is maintained at 82 ° C. Every stick was under use to some extent, that of the rolls forming a different oil-in-water emulsion than Exiting sheet metal is rolled by the temperature and lubricant. Before the first run The amount of lubricant used is regulated. were the rollers on the contact surface with a

The emulsion must not break, otherwise the oil-in-water emulsion selected will be coated. the

phase the metal entering the plant too much emulsion was applied by spray flooding, under

lubricates and strong reductions per pass not using a hand-operated atomizing

possible are. Spray gun for 5 to 7 seconds. Both

The emulsion drips and flows off the rollers in an additional five passes of each billet

a sump or a pit below, 65 roller in the same way for 1 second under

from where, after being allowed to settle a little, she twist of the same selected lubricant

sprayed by a circulation system for the rolling mill just before the billet passes through the rolls

is being pumped. The circulation system can be a filter that has been left running and during the rolling process

spraying was continued so that a coating came off Emulsion covered both the roll and the entering sheet at all times.

Between the various billet specimens, the roller surfaces were rubbed with A cloth, sprinkling with sand and rubbing again before examining another lubricant became. The comparative lubricant used consisted of a bound, soluble oil like that commonly used to make emulsions used for rolling aluminum. This bound oil was in the water added to a concentration of 6 percent by volume and mixed to form an evenly mixed Emulsion stirred A comparison was made using the oil-in-water emulsion without the addition according to the invention carried out. In a In a number of further approaches, one of the additives sodium hexametaphosphate or tetrasodium pyrophosphate was used in each case in a certain concentration. added to an aqueous emulsion, the 6 weight percent of the bound soluble oil to be compared. From the sheet metal obtained Specimens were cut and subjected to various corrosion tests including full immersion in 3% aqueous sodium chloride solution and 24 hours Exposure to 95% moisture at 32.2 ° C was included. The sheets obtained in the tests were also examined visually and rated for their general appearance. Also were the steel rolls examined at the end of each test for the absorption of magnesium on the rolls. The results of these tests are shown in the following table together with tests on AZ 31 B sheet metal summarized, which was rolled for comparison purposes using a lubricant, which consisted of an aqueous solution containing a smaller amount of phenylphenol as a bactericide and 10 weight percent of a polypropylene glycol with a molecular weight of 400 contained.

Attempt no. Complex bi [medium
Weight Total I
in3 ° /
% Attack in i immerse
NaCl
Gases in
I ¹ A, hours % Damage
in 95%
humidity Corrosive
swiftly
ability of % Recording
from Mg up
the reels Appearance
of the sheet Art percent I ¹ Ai hours in mm 24 hours Mg / cm ^z / day Comparison*) none 75 6.35 3 2.49 15th C. Comparison*) none 45 4.75 V ₂ 1.93 0 F. 1 NaHMP 0.05 55 4.75 1 1.83 12th C. 2 NaHMP 0.10 75 4.75 2 1.93 12th C. 3 NaHMP 0.15 45 3.2 1 1.51 10 C. 4th NaHMP 0.20 60 3.2 1 1.59 8th C. 5 NaHMP 0.25 50 4.75 1 1.64 7th D. 6th NaHMP 0.35 30th 3.2 1 2.21 6th E. 7th NaHMP 0.50 30th 3.2 1 1.42 5 E. 8th NaPyrö 0.05 25th 1.6 V ₂ 0.88 18th A. 9 NaPyro 0.10 25th 1.6 V ₂ 1.06 18th B. 10 NaPyro 0.15 15th 0.8 V ₂ 0.81 15th B. 11th NaPyro 0.20 35 4.75 V ₂ 1.09 12th B. 12th NaPyro 0.25 30th 4.75 V ₂ 2.40 10 C. 13th NaPyro 0.35 20th 3.2 V ₂ 2.07 6th C. 14th NaPyro 0.50 18th 4.75 V ₂ 1.53 3 D.

*) Using a solution of polypropylene glycol as a lubricant. NaHMP = sodium hexametaphosphate. % Damage

% Recording

NaPyro
Gases

= Tetrasodium pyrophosphate.

= Millimeter of foam in an upright, cylindrical container
6.35 cm in diameter using a test piece of the rolled sheet 2.54 by 5.1 cm in size
is formed.

Claims (7)

Claim: Lubricant for machining magnesium metal and aluminum metal, consisting of 1. 1 to 10 percent by weight bound soluble hydrocarbon oil, 2. 3 to 15 percent by weight anionic and / or
nonionic emulsifiers, based on the weight of the oil, 3. a sodium salt of phenylphenol as
Bactericide, 4. 0.5 to 10 volume percent high pressure lubricant, based on the volume of the oil, 5. water, 6. a complexing agent for inorganic hardness and optionally off - size of the attacked surface. =% Of the oxide, which is from the magnesium sheet through the rollers on the first pass through the factory after the Heating the metal is added. Brightness evaluation = scale A to F, A = glossy, F = matt. 7. up to 2 percent by weight of defoaming agent, characterized in that the lubricant is used as component 6 trisodium phosphate, Tetrasodium pyrophosphate, sodium metaphosphate, sodium hexametaphosphate, sodium tripolyphosphate as well as the corresponding potassium and ammonium salts and their mixtures in one contains such an amount that the hardness in the solution a) not bound in complexes to a concentration from 25 to 400 parts per million, b) to a concentration below 25 parts per million Million, calculated as calcium carbonate, is set, with the solution still up to 2 percent by weight in case b) contains a defoaming agent.