US1991395A - Process of treating metal - Google Patents

Description

Patented Feb. 19, 1935 STATES r a I 1,991,395 r t V PRQCE'SS ()F METAL V LGy-riLKocour, Chicago, Ill.

No 'iDraw'ing.

Application October 24, 1932, S'erial'Nou639383 Y realms; (01,2054) vThenresent invention relates to treating metals and to drawing compounds for such treatment. It provides .a improved .composition "of those compounds which are used as lubricants in deforming metals, .asin drawing and stamping operations. n n

t .In those mechanical operations which necessiote the subjection of metal to the action of a die it is necessary to provide a. flubrlieant between the metal and the die. The primary purpose of the lubricant is to protect Lthedie from Wear and thus to preserveflits design. and to rolong'its Another reason for the .use of a lubricant is to preserve (the finish, or surface, and even the 15, od hi the W0lIk-pifi l6.., The .most imp r an teature taken into consideration when a"111brioantisehosenjis the preserrationtof theidie. The

dies are in many instances very expensive and are necessarily of .aoeurate dimensions. Any .wear

' men t ke place will naturally ake place at the points receiving the greatest pressures. vS'nch Pressures tend to drive 1the lubrieant .out of th interracial space, and when this isdone the metal work nieceis exposed to tear and the die to wearisof nrimeimnortance. Next. eemes the coverin n wer of the material, by .W ChLI mean the power of the material to resist the squeezing-out action of the die and theworlgr or its resistance to seeso regation. Aside from these essential eonsiderations there ereancillary ones which relate to the eomnosition ofothe materialemnlqyed, and the eiieet of the composition on-the subsequent tigef'ignent or disposition of the drawn or; stamped we 1' Metal parts which have passed through the drawing {or stamping operations are rre uently set aside tor. .a p riod .ofitime during which rusting niig'htoocur hut'i'lolr the tacit that thelubrieant is retained onflthe work. .Itistherefore necesin' such a .oajse'to use ah brioant which proteetthe work as 'dis'tingnishedrromone which will not and, which may .even corrode the metal. StiJlLanother consideration is the removal .of 'T the lubrieatingmaterim Irom the work. Asia rule,

a ehemioal hath is employed which has the proper selective action between the lubricant and the work, .such .as .a-.2% 1or3%,s011ition of, caustic potash or soda, v The superior lubricant is there fer-e one which 'meets'ellthe "foregoing considerations and which can he rea-d ly remoyed'iro'm the work.

Lubricants which are oommonly .used in the art comprise .oils, rats, etc.) in various combinations. Mineral oils or greases ere by .iar' the cl eanest the .choice of lubrieants the lubricating power such as, kieselguhr. "The solid matter increases conStitUentQand'heaVy lubricating oilalone is useful Certain animal and vegetable oils or fats,

aresometimesused as lubricants or are incorporated into them, but theypare rather expensive in comparison with the mineral greases. Animal and 'vegetable'fatsfand oils are subject to becoming rancid and the formation of acid by such a process increasesthe tendency toward corrosion if it does'notactuail'lygprodnoe corrosion. l I

The cormnonmethod of removing such mineral, animal or vegetable materials used eitheralone or in combination, is to place the grease covered article ,[inan' alkaline bath; The mineral oils can thus be emulsified and removed. However, some mi eral g eases are very slow to emul iiv. so that the eleaning action is prolon ed, T

animal .iats and oils on thefother hand, wil

bothlsanoni'iy and em'nls'iiy, and these are more eadily removedifrom the work in a quicker cleanmg operation. Y 7 2o Aside from the various oily and greesvzsnbstances of drawing eomponnds are made up, there is sometimes need a smeilv quantity of finely divided and well dispersed solid material thecovern g-powerof thejlubrieant ;by preventing its'flowing away from 'the'vpoints where it is most desired to'lubricate the die.

Ihe present invention aims to provide a new composition .oflubrieant whiehmeetsall the foreoing .oonsiderations; which permits a reduction in the proportion ofanim'al .fat or vegetable fat and even the elimination of them; which imparts greater hovering power to'the lubricant; which eliminates danger of aeid rjormihg in redients, thereby providing a oorrosion preventing lubricent .and L preservative; and which permits the cloinpoond to be readily .oleaned in .the usual bath in a much shorter time. than'heretoforev In other wordspneebieet .of the invention is l to provide the compound with an ingredient which acts to increase the covering ,powerof the grease. comnosition, which. is harmless to the work lonlong'lstanding in contactwith the ,lu'br'icent, and which is .efiectiveI-in the .flcleaning operation .to .aid in the removal of. the .componnd.

More vsh ,tififcally,'it is ,an object .of the invention to incorporate in ordinarycompounds a" soft solid substanoe which is, reactive .with .a suitable material in a .cleamng bath to'loosen the .com- .50 pound fromthe work. i f

In the iollowing descriptidnbfthe invention I have set iorth w a consider to -.be' the .most. practical embodiment .the'idea, that is, one whiehf eomprises .the addition 1.of not a single and others such as animal fats, primarily be-' cause of the lower cost for the mineral ingredient. The covering power in compounds higher in mineral ingredients is not so great as in compounds having animal fat as the basis, and the emulsification of the high mineral grease compounds is much slower in the cleaning operation. To a compound which contains 9'? parts of heavy mineral oil, such as lubricating oil, and about 3 parts of animal or vegetable fat, such as red oil '(oleic acid), I have1addedl% of alu minumdust as an example of the new composition. Brass waille.,iron tops drawn withv this compound clean very much quicker'than simi-I lar plates drawn with the same' compo'sition havingno aluminum present. The plates could be inserted in the cleaning bath and withdrawn al-.

most immediately. A very'rapid evolution of hy-' drogen gas takes place by the reaction of the aluminum and the caustic alkali, which gas is effective in'forcing the lubricant away from the metal and in, rendering it more readily emulsified. The increased rate of emulsification permits withdrawal of the plate from the, bath with much less danger of theplate gathering oil or grease as it is withdrawn from the bath. In this particular instance aluminum is the preferable metal to be used because'it' forms an alkali aluminate, characterized by the property of preventing brass, "and, some other metals, from tarnishing. Alu'minumis also particularly beneficial because it acts mechanically as a lubricant of the order of powdered graphite.

Thefinerthe aluminum powder, or other metal, such as zinc dust, which is used in the newcompound, the greater its benefits. The covering power is made greater with increasing fineness. The smaller the particles of the metal, the more accurately the work piece conforms to the dimensions of the die. In the cleaning operation, the finer particles will be more widely distributed, oifering a greater surface fora quicker action in the generation of hydrogen." As to fineness, there is no particular criterion; and I have found that the aluminum powder that is used as commercial aluminum bronze paint is satisfactory, and that a"fin'er powder is better; A colloidal distribution of the aluminum or other solid is of course comprehended within the scope of the present invention; v a

A heavy hydrocarbonlubricating oil without admixture of other greases can likewise be used in compositionsof'the present invention, it being only necessary tojadd about 1% of the solid, suchjasaluminum dust, or zincdust, when an alkaline bath is contemplated, or a sufficient quantity of otherymaterial when other types of baths are'contemplated. In using the aluminum dust, I have found that it is not/necessary to have present any material such as'kieselguhr, as the nretalparticles provide the immobile nuclei which retard the oil in its fiow from the space between the die and the work piece. V

A low grade of-mutton tallow may be used as an example of a drawing compound of a different type. Proper admixture of the metal powder, zinc or aluminum for an alkaline bath, is essential to the making of the new compound. Other compounds in which soaps are used, or any other common ingredients, are not excluded from the compositions which may be taken as a base for the new composition of the present invention,

The fact that the lubricant is assured to function, because of the presence of the new solid ingredient makes the new composition valuable as a contribution to the life of the die. The solid prevents segregation of the lubricant film during the operation and thereby avoids the possibility of tearing the metal and wearing the die. This saves time and material. The further saving of time'inthe cleaning operation is also pertinent to its advantages. Besides all the foregoing positive advantages, there are the incidentally allowable alterations in composition of otherwise preferred mixtures towards a higher proportion of the cheaper'rn'ineraIingredient, and towards a lower proportion of the more expensive animal or vegetable greases. And when the animal or vegetable fat (which is so much more easily emulsified and is saponified by the alkaline bath) is entirely eliminated there is an increased protection guaranteed against rusting or corrosion of the metal when the compound is left in contact with the work for a considerable length of time.

As an example of other and different materials which may be, incorporated in the compounds of the invention I cite calcium carbide, a solid which reacts with water to generate acetylene gas. This material has been incorporated in powdered form into a mixture of equal'parts petrolatum and soft tallow. It must'be very finely ground in order that it may bev properly suspended and the fine grinding minimizes what abrasive properties it may. exhibit. Compared to aluminum dust, it is more inclined to settle out. Ordinary water is not a suitable cleaning bath, in spite of the fact that it reacts withrthe calcium carbide. It is necessary to have in the water some material which will attack ,the grease and expose the carbide to theaction'o'f the water. Alkali is suitable for this purpose. In this particular instance, therefore, the alkali solution is a suitable cleaning bath of which the water is the essentialreagent for the, carbide. fl f It is therefore to be understood that the present invention is not necessarily limited to the use of a material which reacts with alkalis, and that various changes may be made in boththe bath and in the composition of the compound, which changes however should be consistent with the results desired. Nor is it to be considered that the invention requires afsolid capable of functioning to increasethe covering power. However, when a solid material such as aluminum or zinc powder, or even a'mixture of them, is em: ployed in contemplation j of cleaning with an alkaline bath, it is to be observed that the metal performs one function because" of its existence as a. solid in the drawing operation, and; another function because of its reactive qualities in the cleaning operation.

The present application is a division of my copending application Serial No. 241,723, filed December 21, 1927, which is now Patent No. 1,884,749, issued October 25, 1932.

I claim: a

1 The method of treating metal which comprises deforming the metal with a die in the pres-v ence of a mineral lubricantcontaining a finely divided solid material having the essentialgasforming characteristics which aluminum dust has in an alkaline bath, preserving the metal in con- I tact with the lubricant as a protective agent'for a considerable period of time, and subsequently subjecting the coated metal to the action of a cleaning bath having the essential characteristics toward the solid which an alkaline bath has towards aluminum dust.

2. The method of treating metal which comprises deforming the metal with a die in the presence of a lubricating grease containing a finely divided solid material having the essential gasforming characteristics which aluminum dust has in an'alkaline bath, and subsequently subjecting the metal coated with the lubricant to the action of a bath having the essential characteristics toward the solid which an alkaline bath has towards aluminum dust.

3. The method of treating metal which comprises deforming the metal with a die in the pres ence of a lubricating grease containing a finely divided solid material capable of reaction in a cleaning bath to form gas for liberating the lubricant from the metal. I

4. The method of treating metal which comprises deforming the metal with a die in the presence of a lubricating grease containing material adapted to react in a cleaning bath to form a gas for the liberation of the lubricant from the metal.

presence of non-corrosive lubricant containing a dispersed material capable of reaction in a cleaning bath to form a gas for the liberation of the lubricant from the metal, preserving the metal in contact withthe lubricant as a protective coating for a considerable period of time, and subse quently subjecting the coated metal to the action of a, cleaning bath capable of reaction with said material to form a gas.

'7. The method of treating brassand the like which comprises deforming the same with a die in the presence of a lubricant containing aluminum in a form which will reactin an alkaline bath to form an alkali aluminate, and subjecting the deformed metal coated with the aluminumcontaining lubricant to the action of an alkaline bath, whereby to form the alkali aluminate as the lubricant is removed from the metal.

CYRIL KOCOUR.