DEST008639MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: August 20, 1954. Advertised on March 22, 1956

GERMAN PATENT OFFICE

PATENT APPLICATION

CLASS 23c GROUP 1 04 St 8639 IVc / 23 c

The inventors have requested not to be named

Standard Oil Development Company, Elizabeth, N.J. (V. St. A.)

Representative: E. Maemecke, Berlin-Lichterfelde West, and Dr. W. Kühl, Hamburg 36,

Patent attorneys

Metal cutting oil

The priority of the application in Great Britain on August 20, 1953 has been claimed

When machining metals, an oily mixture is normally used. Such mixtures can support cutting, for example change the service life of the tool

, 5, extend the friction between tool and Reduce the workpiece, improve the quality of the surface and while cutting act as a coolant. · ■, .-.

• Metal cutting oils are, depending on their application,

ίο: d. H; depending on the relative importance of the above factors, very differently together set. So if cooling is the main task, one will preferably use an oil, which can be quickly emulsified in water. Such oils are called soluble oils. on the other hand is used for difficult machining processes, like cutting hard-to-edit ones. Metals, usually a non-emulsifying one Oil or undiluted cutting oil.

The invention relates to mixtures' from Type of undiluted cutting oils, d. H. on oils that are suitable for difficult metalworking processes

509,698 / 433;

St 8639 IVc / 23 c

where they are applied directly when cutting. A typical example of this the processing of hardened alloyed steels or nickel alloys is a difficult process. An example of this type of machining that is particularly sensitive to the quality of the cutting oil is the clearing.

When broaching solidified alloyed steels or nickel alloys, carbon tetrachloride-containing Mixtures are used that are significantly toxic. The invention aims at mixtures that are less toxic.

Broaching machines are usually large and costly, and this one thing is for everyone Investigations on., This field a laboratory device- desired, with which the usefulness of mixtures for broaching processes can be true.

The cutting action of a broach

ao can, as has been found, be mimicked by standing on a rod of large diameter, which is clamped in a center lathe, cuts a coarse thread and then the thread with a single-point tool, the shape of which corresponds to the thread shape, strikes. the Cutting speed is adjusted to match that normally used in broaching operations is equivalent to. The feed rate can also be selected so that it corresponds to that normally used in the broaching machine used corresponds. In addition to its simplicity, this test method has the part of the fact that a longer cut can be achieved than would normally be obtained by broaching and that the surface finish after machining can be better determined after each cut. Lubricants behave on it similar to their practical use. The usefulness of a lubricant in broaching can be assessed according to the following criteria: according to the surface quality of the Workpiece, 'i.e. to what extent it is free of cracks and all irregularities, according to the nature of the surface of the chip, which is assessed in a similar way, - according to the dimensional accuracy of the Workpiece after cutting, after the service life of the tool, after rusting of the workpiece, after the absence of irritating or toxic fumes during cutting, according to the corrosion resistance of machine parts, according to the visibility of the workpiece through the Lubricant, according to the cutting force.

A number of oily mixtures were determined according to this technique, each mixture being given a relative rating based on its behavior determined according to the above criteria. The 'rating refers to the behavior of C Cl ₄ alone; the larger the number, the less suitable the mixture is.

It has been found that by mixing chlorinated waxes or mineral ^{residues or chlorinated mineral oil distillates from a boiling point above 149 0} , with fatty acid esters of a C ₁₂ - to C ₂₂ fatty acid with a mono- or polyhydric alcohol with up to 10 carbon atoms - ■ Receives drawn mixtures for metalworking of this type.

The advantageous effect of the mixtures according to the invention in comparison with known cutting fluids can be found in the following table.

Test liquid rating

Carbon tetrachloride 1.0

90% isopropyl oleate 1

10% chlorinated luminous oil with 30% chlorine J ² > °
65% isopropyl oleate 1

35% chlorinated luminous oil with 30% chlorine J ^{I) 0}
33V3% isopropyl oleate. ι

33Vs% chlorinated wax with 50% chlorine I
33 ¹ Zs ⁰ Zo chlorinated luminous oil with ['

30% chlorine J

Petroleum ether 60/80 10.0

50% methyl alcohol \

50% TCP (tricresyl phosphate J ^{I> 5}

Isopropyl oleate 2.5 ⁸ S

It can be seen from the table that mixtures according to the invention give extremely good results. Even if the surface of the workpiece does not have the light, fired appearance that is achieved with go C Cl ₄ , it nonetheless has a "true satin-like cut texture" and is therefore suitable.

These results are confirmed by practice. A typical solidified alloy steel 0.5 high strength gave more than 60 passes of the broach using one Lubricant made from 65% isopropyl oleate and 35% chlorinated luminous oil with 30% chlorine before an error occurs, compared to only two or three passes using an effective one known cutting oil.

A further series of tests was then carried out in which, when using a different steel that was more difficult to treat, a mixture of 35% chlorinated wax and 65% isopropyl oleate enabled _{about 50 cuts compared to 275 cuts when using a mixture consisting of CCl 4,} before it failed. Under the same conditions, a mixture worked from 8o ° / e chlorinated kerosine and 20 ⁰ / o isopropyl oleate after 120 cuts still properly and cut when comparing with the above-mentioned C ₄ mixture quite good off Cl

The mixture of 80% chlorinated luminous oil and 20% isopropyl oleate was then tested on a production machine under slightly different conditions. The mixture had approximately the same effectiveness as a mixture of 75 ° / o C Cl ₄ and 25% coconut oil, which is believed to be the most effective commercially available mixture. Unfortunately, it was not possible to _{directly compare neat chlorinated luminescent oil and C Cl 4} , but running the series of experiments gave various indications that their performance compares well when

698/433

St 8639 IVc / 23 c

the addition of a lubricating agent is also required for best results.

In carrying out this work, the interesting and surprising observation was made, that the slightly pungent smell of chlorinated luminous oil by mixing with esters according to the invention, e.g. only 10% isopropyl oleate, was significantly reduced and only weakly greasy odor of the latter was left behind.

ίο Every ester of a C ₁₂ to C ₂₂ fatty acid and a mono- or polyhydric alcohol with up to 10 carbon atoms is effective. In addition to isopropyl oleate, z. B. butyl laurate, ethyl stearate.

The proportion of chlorinated hydrocarbons in chlorine should be as high as it is with the stability of the product is compatible. In this regard it has been observed that a more extracted, a more paraffinic mineral oil fraction results in more stable products in the chlorination.

The proportions of the two components of the mixture can vary considerably. One can Use up to 95% chlorinated hydrocarbon.

Claims (2)

PATENT CLAIMS: 1. Metal cutting oil, characterized in that it consists of chlorinated wax or petroleum distillate with a boiling point above 149 ⁰ and an ester of a C ₁₂ - to C ₂₂ fatty acid with a mono- or polyhydric alcohol with up to 10 carbon atoms. 2. Metal cutting oil according to claim 1, characterized in that the ester is isopropyl oleate. Referred publications:
French Patent No. 1,029,609;
U.S. Patent No. 2,591,570.