CA1311462C

CA1311462C - Process for lubricating the surface of metal parts, made of copper or of iron- or copper- based alloys, to be cold or warm worked and means of lubrication implemented

Info

Publication number: CA1311462C
Application number: CA000582166A
Authority: CA
Inventors: Joseph Schapira; Patrick Droniou; Patrick Hilaire; Jean-Louis Seratinsky
Original assignee: Compagnie Francaise de Produits Industriels SA
Current assignee: Compagnie Francaise de Produits Industriels SA
Priority date: 1987-11-06
Filing date: 1988-11-03
Publication date: 1992-12-15
Anticipated expiration: 2009-12-15
Also published as: ES2039673T3; DE3880084T2; DE3880084D1; ATE87968T1; EP0315532B1; EP0315532A1; FR2622818B1; FR2622818A1

Abstract

PROCESS FOR LUBRICATING THE SURFACE OF METAL PARTS, MADE OF COPPER OR OF IRON- OR COPPER-BASED ALLOYS, TO BE
COLD OR WARM WORKED AND MEANS OF LUBRICATION IMPLEMENTED.

A B S T R A C T

A process for lubricating the surface of metal parts, made of copper or of iron- or copper-based alloys, intended for cold or warm deformation or working opera-tions, which process comprises a conventional surface preparation and the application of at least one lanthanide halide.

Description

1 3 ~ 2 PROCFSS FOR LUBRICATIN6 THE SURFACE OF METAL PARTS, MADE OF COPPER OR OF IRON- OR COPPER-BASED ALLOYS, TO BE
COLD OR WARM WORKED AND MEANS OF LUBRICATION IMPLEMENTED.
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This invention relates to a process for lubricat-ing the surface of metal par$s, made of copper or of iron-or copper-based alloys, to be cold or warm worked.
It is also concerned, as new commercial products, I0 with lubrication means used in the aforesaid process, these means essentially comprising a lubricating agent as well as compositions containing this agent.
The alloys concerned are those in which copper or iron make up the main element and which particular~y comprise brasses, bronzes, cupro-nickels, nickel-silver, steels, cast irons and stain1ess steels.
When a metal or alloy must be cold worked, parti-cularly when it is at room tempera~ure before the working process which may be extrusion, cold-heading, drawin~ ou~
or ~ire drawing, or when the elastic limit of the metal is modified by raisin~ i~s te~perature be~ore the working process, which may then be drop-~orging, swedging or die stamping, it is necQssary to previously reduce the fric-tional ~orces, in order to restore the working or forming pressures down to a level compatible with the stren~th o~
materials making up the tool used.
To that end, it i5 known to resort to a lubrica-tion making lt possible to obtain a v~ry low frictional coe~ïcient which must be maintained throu~hout the duration ot the de~orming or workiny process so that the work~d part may feature proper sur'~ace conditions and tha~
too fast a wear o~ the tool may be avoide~.
The means used up to now in order to lower the frictional coefficient consist in per~orming a preparatlon of the surface o~ the part to be worked followed by lubri-cation.

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The surPace preparation may be a degreasing, pickling, shot-blasting, refining, phosphatizing, oxa1a-tation, galvanization or coppering (or copper-plating) or a combination of several of these treatments.
S The ~etal thus prepared is ~hen coated with a lubricating layer which may consist of a lubrtcating oil based on mineral, animal, vege~
table or synthetic oils comprising additives of the so-called extreme pressure type or E.P. oils, natural or synthetic fa~ty esters and anti-oxida~ion, * o~ a soap resulting from the reaction between a natural or synthetic ~atty acid, having a carbon chain comprised be~ween C10 and C22 and an alkaline hydroxide, an amine or an alkanolamine, this soap furthermore comprising dispersing agents, sequestering agents avoiding the ~ormation o~ insoluble soaps, bactericides and fungicides or * o~ a solid lubricant used alone or in dispersion in one of the two products described above, the most commonly used solid lubricants being molybdenum disul~ide ~or the cold working processes and graphite ~or the warm workin~ processes.
Molybdenum disul~ide ~nd graphite prove qui~e sa~isfactory as ~ar as the lowering o~ the tric~ional coef~icient is concerned but have a certain number o~
major drawbacks since when use~ under the ~orm o~ powders or very sticky black dispersions dif~icult to remove, they give rise to a dirty working station, dirty worksho~ and ~ dirt~'marks on the ~reated parts and tools.
~ In addition, the di~iculties in remov1ng molybdenum disul~ide and gra~hi'te from the treated sur ~aces bring about problems in the eourse o~ operations subsequent to the working or ~orming process, i.e. ~or example prior to pain~ing, m~chining, starting a new working cycle and other thermal treatments which ~y be hindered by the presence o- sul~ur in the case ~olybdeno~

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disulfide is used.
Finally, the olog~1ng o~ the supply circuits is frequent still because of the same dif~iculties in remov-ing the products concerned.
The whole o~ these drawbaoks associated with the use of molybdenum disulfide and graphite has led the man skilled in the art in the course of the ~ast twenty years to s~udy lubrica~ing eo~positions based on mineral salts or synthetic products for which, due to a lack o~ efti-~o ciency, no large scaled industrial application could be found.
The merit of the Applican~s is that, at the con-clusion o~ a thorough research, they pro~ided a solution to this difficult problem; more especially they ~ound that it was possible to confer to the surfaces of metal parts to be cold or warm worked a frictional coe~icient which is at least as low as with the molybdenum disulfide or with graphite, without bringing about the drawbacks asso-ciated with the use o~ these produc~s, by treating sa~d metal parts following the conventional sur~aoe prepara-tion, ~which may include a degreasing, shot-blasting, re~ining, phosphatizing, oxalatation or several o~ these trea~ments) with at least a lanthanide halide ~hich is preferably used in the form o~ an aqueous or oily disper-sion or wrapped in a wax or still in the ~orm o~ a mixture . with a pulverulent dry soap, ~he produots concerned, which : c~n be ~asily removed, being neither black nor s~icky.
Consequently, the process according to the inven-tion for lubricating the surfaoe o~ metal parts of copper or ~f iron- or copper-based alloys, intended for cold or ' warm workin~ or forming operati'ons, is characterized by `. ~he ~ac~ that, following the conventional sur~ace prepara-tion, there is applied to the surface nf said parts at least one lanthanide halide, preferably in the form of an ~5 aqueous or oily dispersion or of a mix~ure with a wax or l with a dry soap in form of a powder.
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~ 3 ~ 2 The lubricating agent accordin~ to the invention, intended for lubricating the surface o~ metal parts o~
copper or of iron- or copper-based alloys, to be cold or warm worked, is characterized in that it is consisting essentially of at least one lanthanide halide.
The aforesaid lubricating agent is, pre~erabl~, used in the ~orm of an aqueous or oily dispersion or as a mixture with a wax or with a pulverulent dry soap.
The aforesaid lubricating agents, dispersions and mixture as well as the concentrates from which the disper-sions are prepared, constitute novel ~ndustrial products or mixtures.
The lanthanide halides involved in connection with the present invention, are preferably ~luorides, chlorides and iodides, the fluorides being most particularly prefer-r~d: the preferred lanthanides are yttrium, lanthane, cerium and neodyme, and most particularly lanthane and cerium; lanthanides o~ the group comprising samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and thorium may also be used.
Cerium ~luoride was already added to greases intended for use under extreme temperature or pressure conditions ~us patent no. 4,507,214); cerium and lanthan2 fluorides were used in the pressure die-casting o~ molten metals ~US Patent No. 3,380,280).
How~ver, these prior art references not only do not relat~ to cold or warm workins of copper- or iron-base~' metals but moreover do not contain any suggestion likely to induce the man skilled~in the art to apply the compounds in question to this technical field.
As stated above, lan~hanide halides can be used in the form of aqueous or oily dispersions or wrapped in a wax or with a pulverulen~ dry soap.
First, as regards the aqueous dispersions o~
lanthanide halides, they generally comprise sur~actan~s .
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~ 3 1~ 6 2 having a wetting or dispersing action and which can be selec~ed from - anionic deriva~ives and particularly, on the one hand, from salts formed between an alkaline hydroxide, an amine or an alkanolamine and a natural or synthetic fatty acid having a carbon chain of ClO to C2~ and, on the other hand, from salts of an alkaline hydroxide, of an amine or of an alkanolamine of a sul~onated or sulfated fatty body, of sulfated fat~y alcohols, of sulfa~ed fatty a~ides, o~ sulfated non-ionic deriva~ives, of sulfona~ed hydrocarbides, o~ sul~onated alkylaryls, - non ionic derivatives and particularly polyethylen2-glycol esters, oxyethylene and oxypropylene derivatives from hi~h molecular weight alcohols, from amides, from substituted amides, from fatty acids, from esters or amines.
These aqueous dispersions may also contain one or several sequestering agents, one or several corrosion inhibitors, one or several preservatives or also simulta-neously several of these dif~erent products.
The se~uestering agents may also be selected from the group containing E~TA, NTA, phosphona~es from alkalin0 metal salts or alkanolamine and polyphospha$~s.
The corrosion inhibitors may be selected from the alkaline metal salts or salts o~ alkanola~ines o~ sul~onic acids, carboxylic acids, oleylsarcosinic acids and alkyl-arylsul~unamidocarboxylic acids.
. The preservatives may be selected fro~ ~ormalde-hyde f triazinic derivatives, orthophenyl~ormald~hyde or its sodium salt.
The oily dispersions may contain mineral oils obtained from petroleum and which may be para~tinic oils, naphthenic 0il5, aromatic oils. The oil may 3150 be a synthetic oil such as a polyal~aole~in or an alkylate, a vegetable oil such 35 colza or rapeseed oil, castor oil, t .

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~ 3 1 ~ 2 soybean or animal oil such as lard oil, n~at's foot oil also called cattle foot oil or bubulum oil. These oilY
dispersions may contain, besides, synthetic fatty esters such as polyethyleneglycol esters and viscosity agents S such as aluminosilicates and modified carboxylic deriva-tives.
They may also eontain one or several dispersing agents, one or several preservatives or also simultaneous-ly several of these products.
The dispersing agents may be calcium or aluminum alkylarylsulfonates.
The preservatives may be selected from the tria-zinic derivatives.
The waxes used for wrappin~ the lanthanide halides may be mineral waxes such as microcrystalline waxes or paraf~ins as well as animal or vegetable waxes.
Furthermore, ~hey may contain texturing agen~s making it possible ~o modify the appearance o~ the final product such as fatty acid esters, particularly polyglycol carboxylates such as polyethylene glycol oleate.
The dry soaps in the form of powder can be consti~
tuted by the products of the reaction between alcaline and/or earth-alcaline hydroxides with at least one fatty acid of natural origin or obtained by synthetis having a carbon chain of C10 to C22.
Finally, it is possible to provide ~he aforesaid lubricating products with inert fillers which may be - carbonates, sulfates or water.
The lubricating ag~nt and the dispersions and mixtures for its implementation in accordance with the invention onto the surface of par~s to be worked or formed may be used - by spraying by means of an air gun, - by cold or warm dipping, - manually by painter's brush coating, roller coatin~, - by rubbing a wax stick, or also ..
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- ~31~2 - by wrapping by passage through a wire drawing box con-taining soap in the form of powder.
When the lubricating agent according to the invention is applied under the form o~ an aqueous or oily dispersion or under the ~orm of a mixture with a ~ax, its concentration in the application medium is 0.05 to 60% by weight; preferentially. it is from 0.05 to 5X by weight in the case of an aqueous dispersion, from 0.1 to 15% by weight in the case of an oily dispersion and from 5 to 60~
by wei~ht in the case of a mixture with a wax and from 0.05 to 5X by weight in ~he case of a ~ixture wi~h a pul~
verulent soap.
In order to prepare ~he aqueous dispersi~ns or oily dispersions, powders or liquids may be used, the said powders or liquids comprising in addition to the l~ntha-nide halide(s) the other constituents o~ the dispersions under concentra~ed form.
These concentrated products may contain at least one lanthanide halide in a proportion which i5 respective-ly ~rom 5 to 30X by weight in ~he case o~ those intendedfor providing aqueous dispersions and from 1 to 50X by weight in the case o~ those intended ~or providing oily dispersions.
When applying the produc~, the dilu~ion i~
required, is performed by means of water for the aqueous dispersions and by ~eans o~ an oil or o~ a petroleum solvent in the case o~ the o~ly dispersions.
The lubricating a~ents accordin~ to the invent~on m~y .be introduced into the applica~ion medium simulta-neously with a conventional lubricant; advant3geouslye a se~ ot products provided separ~ely from each other and making it possible to carry out ~he process according to the invention can be made a~a~lable to ~he user. viz.:
- a ~irst product essentially consisting o~ lan~hani~e halide and particularly cerium fluoride and~or lanthane I ~luoride having a concentration ~rom 1 to 99.9%, and .~ .

~ 3 ~ 2 - in the case ~he process is per~ormed by implementing an aqueous dispersion, a second product resu1ting in the soap deposit, - in the case the process is carried out by implementing an oily dispersion, a third product constituted by an oil which may comprise the additives set for~h in s~ch a case, or - in the case the process is carried out by mixture with a dry soap in the ~orm o~ powder, a fourth product constituted by this dry soap in ~he ~orm o~ powder;
the first and second, third or fourth product, as the case may be, could be sold on the ~arket under the ~orm of ~kits".
Be~ore illustrating the invention by means of the following comparative examples incorporating a ~ew embodi-ments which although being advantageous in no way limit the invention, emphasis should be laid on a par~icular ad~antage lying in the capability of performin~ on ~he same site of production and with a sole line o~ sur~aee preparation and lubrication, the working or ~orming o~
various parts which, i~ the prior art processes were applied, would require dif~erent sur~ace preparati~ns.
E~AM~
A comparative test is per~ormed by successively usin~ in the so called ring-test, dispersions in oil o~
cerium fluoride, graphite and ~olybdenum ~isul~ide. The graphita and the molybdenum disul~ide used are of a quality commonly chosen for this type of use, viz.
- a 'graphi~e powder with a grain size dis~ribu~ion or gr,anulome~ry such that 5~X o~ the grains have a size lower than 8 ~m and 100% a si'ze lower than 32 ~m, the speci~ic BET surface being 16 ~2/gl this graphite mi~ht be the one known as o~ quali~y T10 ~ro~ LONZA, - a molybdenum disulfide powder with 99% purity and a grain size distribu~ion such tha~ 50X of the grains hav~ a size lower than 8 ~m, tor example the one o~

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. ' quality no.4 sold by KS PAUL.
The cerium fluoride used is under the ~orm o~ a white powder with 98X purity and a grain size distribution such tha~ 74X of the grains have a size lower than 100 ~m.
The ring-test used for measuring the ~rictional coefficient obtained by means of the various oily disper-sions is disclosed in the work "Metal de~ormation process:
friction and lubrication" by J.A. SCHEY, page 270-271, published by Marcel Dekker in 1970.
This tes~ makes i~ possible to determine the fric-~ional coefficient existing between a tool and a material subjected to a plastic distortion or deformation under particular surface and lubricatin~ conditions.
Thus, when a metal ring is compressed between two flat anvil inset stakes or swedge blocks, it can be observed that the inner or bare diameter, for a given j crushing pressure, depends upon the ~rictional conditions;
; the lower the frictions, the larger the bore.
The rings used for the test purposes are made of XC 10 quality steel and have the following dimensions:
- outer diameter ............ 42 mm - inner diameter ............ 21 mm ; - height .................... 7 mm.
The tool used for the test proposed consists o~
two flat anvil inset stakes or swedge blocks made ot steel of the ~ 20 OC 12 ~rade. The height reduction of the ring during the ~ests ranges ~rom 20 to 40X.
The results derived ~rom the measurements of the heig~t variation and of the inner diameter variation make it possible, through preestablished nomographs or calcu-lation sheets, to in~er the value' of the contact fric~ion coefficient.
` In connection wi~h the present example, the rings were lubricated by dipping a~ room temperature into dispersions with 5% by ~cight o~ graphite, ~olybdenum disul~lte or cerium ~luoride in a naphthenic oil having a :i .

, ' ' ' ' viscosity equal to 75 centistokes at 40-C.
The results obtained are recorded in Table I.
T~8~E I
_ _ _ _ T t Friotion Ring aspec~
es coef~icient after distortion . _ _ _ __ _ Mineral oil ~ 5X CeF3 0.13 bright and clean Mineral oil ~ 5% MoS2 0.13-0.14 black and sticky Mineral oil + 5X graphite 0.13-0.14 black and sticky _ _ This example shows that the lubricating agent according to the invention makes i~ possible to obtair satisfactory frictional coefficients for a result which is visually more aesthetical and without any contami-nants lef~ on the treated par~.
EXAMPLE ~
A comparative tes~ is performed under industrial conditions and consisting o~ ~orward wire drawin~"
process per~ormed on parts o~ the hollow billet-type of steel.
Conventionally, the billets intended for the ~orward wire drawing process ar~ prepared by successive-ly proceeding with a phospha~iza~ion which may be carried out in a phosphatizin~ bath o~ the ~ype which is marketed under the trademark THERMOGRANODINE 701~ by Compagnie Francaise de Produits Industriels ard imple-. men~d in the usual way; this phosphatizing operat~on is ~ollowed ~ith a dip-coating in an aqueous dispersion o~
MoS2 comprisin~ 5% by weight of this produc~.
The aforesaid ~orward wire drawing cannot possi~
bly be carried out by proceeding wi~h the phospha~izing operation ~ollowed with a simple lubrication base~ on a : soap deposit: actually, a quiok deteriora~ion of ~he 3 35 tool then takes place and the parts obtained do not come up to requested dimensions.

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~L311~2 In the present comparative test, ~wo series o~
600 billets of the a~orestated ~ype are successively subjected to a phosphatizing process by means of the THERMOGRANODINE 701~ and to a dip-coating lubrication by using in the tirst case a conventional aqueous ~isper-sion with 5% by weight of MoS2, and in the second case a mixture of an a~ueous dispersion with 0.5% by weight o~
CeF3 and of a solution with 5X by weight of an anionic surfactant consi~ting of soap, in the present ease of sodium stearate, for example the one marketed by Compa-gnie Francaise de Produits Industriels under the trade-mark PROLUB TS 438 and which genera~es a lubrica~ing soap deposit.
The conditions for implementing the lubrication are recorded in Table II.
~BlE ll i -- _ Prior art According to the Bath MoS PROLUB TS 438 . 5X
5% disp~rsion CeF : 0.5X
composition in water wat~r qs 100 _ __ ~__.
Temperature 60C 80-C
~ _ Dipping duration 1 minute 5 minutes 25 _ ~ _ _ The dimensional check carried out on the series o~ 600 parts, distorted a~ter the trea~ment embodying the process according to the invention, yields results identical with the ones recorded a~ter the treat~ent according to the prior art process: these results show . testify that the worked or de~Pmed parts ar~ ~n com-pliance with the eolerances set rorth in Table Il;:

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~31~ 4~2 TABLE lll . _ _ _ __ Tolerance in mm around ~he standards _ outer diameter 0 1 from 0 to + 0.~5 outer diameter 9 2 from 0 to ~ 0.40 outer diameter 0 3 from 0.10 to ~ 0.20 inner diameter "inner 0~ ~rom 0.30 to + 0 The outer diameters 0 1, 0 2, 0 3 and the inner 0 diameter "inner 0" are specific to the shape of the part and are shown on the single figure of the attached drawing showing said part in axial section, as a, b, c and d respectively.
The check o~ th~ distortion angles by profile projectton yields similar results for both processes.
The distorted or deformed parts after treatment by implementing the process according to the invention can easily be handled and are olean in aspect oompared with the parts obtained by way of th~ prior art process.
2dThis example oonsequently demonstrates that, thanks to the invention, it is possible to carry out on an industrial scale cold de~ormations of parts which in the prior art required the imple~entation o~ molybd~num disulfide; the advantage supplied by the invention lies in the cleaner appearance ot ~he parts thus o~tained which was not the case with the parts treated acoording : tc the prior art which therefore had to be cleaned . before the subsequent operations.
. EX~MPLE_~
- 30A comparative test is carried out und~r indus-: trial conditions; i~ oonsists of a forward and then of a . backward wire drawing on steel billets by means o~ a . hydraulic press having a power a 600 T lmandrel rod ~e~d speed= 40 mm/s~.
`` 35Two series of 2100 billets of the afores~id type i.are subJected to successive operations o~ forward and '` !
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backward wire drawing after a lubrlcating treatment according to the process o~ the prior art ~or the ~irst series and according to the process in compliance with the invention for the second series, each o~ these treatmen~s being performed after a phosphatizing opera-tion with the THERMOGRANODINE 701~ product which is a phosphatizing bath sold by Compagnie Française de Pro-duits Industriels and which is implemented in the usual way. The characteris~ics of the two lubrication treat-ments are recorded in Table IV.
TABLE IV
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According ~o the Prior art invention _______ ____ ______ __ ______ ____ ____ 5% by weight of Lubricating Lubricating soap lubricating soap bath PROLUB TS 438 : 5% PROLUB TS 438 and composi~ion by weight in water 0.5% by weight o~
CeF~ in water _ .
Treatment .
20 duration 5 minutes 5 minutes Bath _ _ . _ temperature 80~C 80~C
. _ _ _ The operations o~ forward then o~ backward wire drawing being carried out, 50 parts from each series are sampled out and subjected to a conventional dimension check and to comparative ~easurement o~ the standard deviation. The recorded results are to be ~ound in Table V.
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~ _ , _ . Prior art AC~ordlng to the . ____~______ ____ ____________ Standard deviation backward wire drawing 0.135 m~ 0 106 mm _ . _ __ Standard deviation ~orward wire drawing 0.0~6 mm 0.049 mm _ _ _ _ ' !
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--` 13~62 1~ , These results clearly demonstrate that lubri-cation according to the invention makes it possible to carry out cold working or deformation processes on an industrial scale with more reliability than the process according to the prior ar~.
EXAM~L~ 4 A comparative test is carried ou$ under indus-trial conditions and consists in a forward wirc drawing of steel parts, namely of two series of 5~0 steel billets: the operation is performed on a hydraulic press having a power of 1600 T (speed o~ the mandrel = 50 mm/s).
The billets are previously phosphated by means of a bath o~ THERMOGRANODINE 701~, then are lubricaked as follows:
- the first series i5 successively lubricated by means of an anionic soap for example PROLUB TS 438 with 5%
by weight in water ~for 5 minutes at 80-C) then by means of MoS2 under the form of powder applied with a brush, - the second series is lubricated by dipping into an aqueous dispersion containing 5X by weight of an anionic soap which may consist of the one sold under the trademark PROLU8 TS 438 and 0.5X by weight of CeF3, whereby the dipping duration is 5 minutes and the te~pe 25 rature of ~he dispersion is 80'C. .
Followin~ the backward wire drawing, the dimension check performed on the two series o~ 500 parts prove to be in compliance with the standards and iden~ical for both cases. mphasis should be laid on ~he adYantage of the cleaner appearance and on the non-conta~inating character o~ the lubricated parts by implementing the process according to ~he invention which, furtherm~re, makes it possible to carry ou~ the lubrica~ion as a single step, whereas the process accordin~ to ~he prior art required ~wo steps.
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. , , 1 3 1 ~ 2 More generally speaking and with re~erence to the examples 2, 3 and 4 which are performed on the same site of industrial production, the fact should be stressed that in the case of lubrication according to the prior art, it is common to resort to dif~erent processes depending upon the working or deformation difficulties, whereas the process according to the invention enables a single operating sequence for the surface preparation to be used in the three cases.
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EXAMPL~5 A co~parative test is carried ou~ under industrial conditions by means o~ the cold deformation of stainless steel billets of grade Z6 C13, ~he deformating being performed by means o~ a mechanical press having a power of 600 T.
Two series of billets are prepared ~or deformation purposes respectively by implementing prior art techniques for the first series and the process according to the invention for the second series.
The two lubricatin~ treatme~ts are preceded by a surface preparation treatment identical in b~th cases and consisting of an oxalatation based on sal~s o~ oxalic acid which can be supplied by means o~ the product sold by Compagnie Francaise de Produi~s Industriels under the trademark THERMOGRANODINE SS1 and SSS.
The lubricating treatment according to the prior art successively comprises a treatment by means of an anionic lubricatin~ soap PROLUB TS 438 with 5X by weight in water, whereby the duration is 5 minutes a~d the tem-perature is 80'C then a dip-coating in a ~ispersion with 5X by weight o~ MoS2 in water, whereby the duration is 1 minute and the temperature o~ the bath is 60-C.
The lubricating treatment according to the inven-, 35 tion comprises a single treatment step by means o~ an aqueous dispersion with 0.5Z by weight of CeF3 which also 5, ~31~62 contains 5X by weight of PROLU~ TS 438, whereby the dura-tion is 5 minutes and the temperature of the dispersion is 80'C.
The results obtained following the de~ormation s process are recorded in Table VI:
TA~LE YL

Parts treated Parts treated according to the according to the prior art invention _ _ _ Press power (in tons) 180 180 _ Size checks good good _ _ _ _ ~
Appearance of black clean the parts sticky bright 15 ~ - _ It should furthermore be underlined in this example that the lubrication trea~ment according to the invention was performed in a single step, whereas two steps were required in the treatment accor~ing ~o the prior art.
EXAMPLE
A co~parative test is carried out with the warm wire drawing of brass under industrial conditions consist-ing in heating brass billets up to 750-C then in carryin~
out the warm wire drawing in order to obtain the w1re diameter ranging ~rom 5 to 11 mm, whereby the wire dr~w dies are previously lubricated.
Thts lubrication is enswred in compliance ~ith prior: art by ~eans o~ a sol~id lubnicant, viz. graphite, wrapped to an amount ot 50~ by w~igh~ in a para~tnic wax having a drop point of ao~c, ~; whereas th~ lubrication according to the invention was carried out by means o~ a mixture with 50X by weisht o~ CeF3 in the sa~e paraf~inic wax.
The wire drawing pQrformed a~ter lubrica~ion accord1ng to the invention results ln a wire havlng a - ~3~462 cleaner aspect unlike the results obtained when using the lubricant according to the prior art. No abnormal wear of the wire draw die was observed.
EXA~PLE 7 Galvanised steel wires are subjected to an indus-trial test of dry wire drawing. The lubrication is carried out by means of "soap boxes" in which the lubricating soap is introduced on a dry basis. The passage o~ the wire into the "soap box" ensures the coating with lubrican~ by li-quefying on the hot wire of the dry soap, whereby allowing the passage into the wire draw die.
The test is performed on an wire drawing banch comprising eight wire draw dies making up possible to ob~ain a thorough diameter reduction of 2.4 mm at entrance up to 0.69 mm at exit.
The wire to be extruded is made of steel having a content of 0.45X of carbon and is galvanised. Its resis-tance is of 180 kg/cm .
The addition of 1% o~ CeF3 into th~ product PROLUB
TN 110 sold by Compagnie Francaise de Produits Industriels and consisting of sodium stearate, ~nables the wire drawing to be performed at a speed of 540 mJmin whereas PROLUB TN 110 alone does not make this possible. In the la~ter case, a quick wear of the wire draw dies and breaking o~ the wire is observed.
EXAMPL~_~
An evaluation test o~ the lubricatin~ power is carried out in compliance wi~h the automobile standard CNOMO D 55 1136 on a Shell Royal Dutch 4 balls machine.
This ~est is a co~pratie test carried out by add-ing various lubrica~ing a~en~s to a para~fin o1l having a viscosity of Ç20 centistokes at 40~C such as ENERPAR 27 sold by Societ~ Française BP, the said agents being identi~ied in Table VII.
The av~rag~ diameter o~ wear impression obtained with a load of 100 kg is measured. A s~all diameter ~ 3 ~ 2 testifies of a good lubrication. The test is perform8d at room temperature.
TABL~ Vll Tested lubrtca~ingDiameter of agents impression __ _ Paraffin oil 1.6 mm Paraffin oil ~ 5X MoS2 0.45 mm Paraffin oil ~ 5% CeF3 0.~5 mm Paraffin oil ~ 5~ LaF 0.45 mm _ 3 Lanthane f luoride used is under the form of a white po~der having a purity higher than 99~ and a grain stze dis~ribution such that a~ least 74X of the grains have a size lower than 100 microns.
From the results recorded in Table VII, it appears that cerium fluoride and lanthane fluoride can be consi-.
dered as additives making it possible to obtain a satisfac-tory lubrication, comparable with that obtained with molyb-denum disulfide, while providing the treated parts a more aes~hetical aspect to the part.

. ,~ ,, - - , .

Claims

1. A process for lubricating the surface of metal parts, made of copper or of iron- or copper-based alloys, intended for cold or warm deformation or working operations wherein, after the conventional surface preparation, there is applied at least one lanthanide halide to the surface of said parts.

2. A process according to Claim 1, wherein the said lanthanide halide is applied in the form of an aqueous or oily dispersion or of a mixture with a wax or of a mix-ture with a pulverulent dry soap.

3. A process according to claim 1, wherein the said lanthanide halide is selected from the group consist-ing of fluorides, chlorides and iodides and preferably consists of a fluoride, the preferred lanthanides being yttrium, lanthane, cerium and neodyme.

4. A process according to claim 1, wherein the said lanthanide halide is selected from the group consist-ing of lanthane fluoride and cerium fluoride.

5. A process according to claim 1, wherein the application onto the surface of parts to be worked of the lanthanide halide in the form of an aqueous dispersion, of an oily dispersion or of a mixture with a wax or of a mix-ture with a pulverulent dry soap is performed - by spraying by means of an air gun, - by cold or warm dipping, - manually by painter's brush coating, painting roller coating, - by rubbing a wax stick, or still - by wrapping by passage through a wire drawing box con-taining soap in the form of powder.

6. A process according to claim 1, wherein the aqueous dispersion through which lanthanide halide is implemented, comprises at least a surfactant having a wetting or dispersing action.

7. A lubricating agent for the lubrication of the surface of metal parts made of copper or of iron- or copper-based alloys, intended to be cold or warm deformed.
essentially consisting of at least one lanthanide halide

8. A lubricating agent according to claim 7, wherein the lanthanide halide is a fluoride, chloride or iodide of lanthane, cerium, yttrium or neodyme.

9. A lubricating agent according to claim 7, wherein the lanthanide halide is selected from the group consisting of the fluorides of lanthane and cerium.

10. An aqueous or oil dispersion or a wax-based mixture or a pulverulent dry soap-based mixture comprising a concentration of from 0.05 to 60% by weight of the lubricating agent essentially consisting of at least one lanthanide halide.

11. An aqueous dispersion according to claim 10, comprising from 0.05 to 5% by weight of the lubricating agent essentially consisting of at least one lanthanide halide.

12. An oily dispersion according to claim 10, comprising from 0.1 to 15% by weight of the lubricating agent essentially consisting of at least one lanthanide halide.

13. A wax-based mixture according to claim 10.
comprising from 5 to 60% by weight of the lubricating agent essentially consisting of at least one lanthanide halide.

14. A mixture on the basis of a pulverulent dry soap according to claim 10, comprising from 0.05 to 5% by weight of the lubricating agent essentially consisting of at least one lanthanide halide.

15. A pulverulent or liquid product capable of providing dispersions according to claim 10, including beside the lanthanide halide(s) the other constituents of said dispersions in a concentrated form.

16. A set of products capable of implementing the process according to claim 1 and conditioned separately in - a first product essentially consisting of at least one lanthanide halide. particularly cerium and/or lanthane fluoride, with a concentration of from 1 to 99.9%, and - in the case the process is performed by implementing an aqueous dispersion, a second product resulting in a soap deposit, - in the case the process is carried out by implementing an oily dispersion, the third product consisting in an oil which may comprise the additives set forth in such a case, or - in the case the process is carried out by mixture with a dry soap in the form of powder, a fourth product constituted by this dry soap in the form of powder.