CS251787B2 - High-temperature lubricant for chipless metal hot forming - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high temperature grease for chipless metal forming of a metal comprising a solid lubricant from a completely thermally degrading organic product.

Swiss Patent No. 596,294 discloses a high-temperature naïve of graite, an alkyeen polymer or a mixed polymer and a dispersant. The polymer used in such materials is completely destroyed during metal forming, starting from ₍ initially, the melt of the polymer is poorly active and its gaseous decomposition products are poorly effective).

German Offenlegungsschrift No. 24 30 249 discloses a high level of performance. a thermoforming metal naphtha based on phosphate boronane glass, a naphtha additive and an organic product having a driving action and decomposing completely.

These known lubricants have an excellent lubricating effect. When ponuřtí at high temperatures, esp ^Part E ^P s ^ otéití ^P ro tools and ^ ly, ^kt ns m ^ s pulse of ³⁵⁰ ° C and Ex-I pulse of ⁶⁰⁰ ° ^C and ^Ys, Sc VSA ^op ozoruje r ^y c ^h lysed ^p okles eraser ^Pooh to uptake.

Addition of alkaline phosphoroborane melt provides a product which, as a further drawback, exhibits poor readiness of the hot surfaces. In order to overcome this drawback, it was necessary to stabilize the dispersion of the maize with silicic acids. However, silicic acids lubricate, as such, an adverse effect on the lubrication properties and the tool life.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high level of performance. maaivo, which should not shown nedootatky and ^y tv ^and re ^l ob ^yp s te ^{l ll} tt and ^at above ⁶ 0 ⁰ uihvřen ^é perfectly ^Prior veloped ^f ilm ^y naiva.

Task b ^y l is achieved by the high temperature naiva invention for beatřískové metal forming hot tbsaaujícíUt fixed to ^ VOVO substances and organic product rozkládaící under heat without zb ^y TKU which is characterized in that it comprises a fixed maaivovou agent, preferably graaft mnotževí in the range of 1 to 90%, the organic product rozkladjící under heat without zb ^y TKU, in mN ^ St! 1 to 50%; 1 to 80% and an organic stabilizing agent in m < 2 > 0.2 to 80%, wherein the inorganic additive is a mixture consisting of a boron compound in an amount of 0.2 to 25%, a polyphosphoric agent in an amount of 0.2 to 98.8%, and a silicate of a silicate in an amount of 1 to 99.6%, and organic stabilizing agent comprises polyvinyl lolyviiylalOtUot, lolyehchuaiay, lolyvii ^y liutyrlty, lotyviiyliutyraly, polyekkyláty, polystyrenes, cellulose, and one or ^^ Mo in mutual Sims.

The polyphosphate and boron compounds are preferably used in sparingly soluble or insoluble form. ‘

Vysco ^ ce ^^! Naive according to the invention can, as the boron compound include inorganic additives borax, boric oxide, Boo-th tetrahydrate boron compounds of formulas KB, O _g or zinc borate, each one of ^^ simělch or jointly. .

Vysco ^ ce ^^! The naïve according to the invention preferably contains as the polyphosphate in the inorganic additive Macrogol or the Kurrol salt of the formula (NaPO4).

As an alkaline silicate in the inorganic additive, the maize according to the invention contains sodium or potassium water glass having a silicon dioxide content of 21 to 47% by weight.

The celluloses in the organic stabilizing agent are preferably alkylcephene.

Vysco ^ ce ^^! Preferably, the naïve is in the form of a 5 to 50% aqueous dispersion.

P and ^P ^ o ^ iti s te ^ ^p ^ OTC h to ³⁵⁰ ° C a ^b exceed hzívo or ^ ni ^ y ^^ ^ UKC decay is completely rolled, in mrιntževí weight to 50% while the Mn ^ St! at interior temperatures over 600 ° C and above Hnefrrá ^e further on the maximum possible ^{for the} SAFETY ^{of 5%.}

Ppouiií as preferred compounds listed insoluble or slightly soluble compounds is particularly advantageous zřeteeem wetting hrokých surfaces and particularly zřeteeem to uniform thickness layer mmaiva high temperature on the surface of the forming tool and / or TV ^and řenýc ^hp UBJECT MATTER ^of at te ^ o ^ CH ³ above 50 ° C and Ex ^As T s ^{e p} te ^ o ^ CH ⁶⁰⁰ ° C and hills.

up to 50% by weight of the organic product of the inorganic additive according to the invention;

1 to 90% by weight of the solid constituent, 1 to 80% by weight, 0.2 to 80% by weight, of the organic composition of the composition, can be seen as the weight ratio of the individual components.

In a preferred embodiment, the organic product decomposing without residue in maaive ^ ^p ro ^ u ^ three per te ^ ol ^{and 3} 50 ° C ^U sing ^plated in mnnžžsví maximal ^SH měOnostn ^{5 0% ORC} CEE ^and this amount ^ Ear candle l ^ ^ SO ^ U is ^P ro interior temperatures 6 ⁰ 0 C and ^{characterized} on SSI ^h ěěOnostn maximum ^{of 5%.}

Typically, typical temperatures at 350 ° C may contain 40 to 40% solids solids, 10 to 50% organic product, 0.2 to 5% inorganic additive, and 0.2 to 5% organic stabilizer composition.

At this maaiva Ooi ^ ^p ro t ^ Lot ¹⁶⁰⁰ ° C, ^{characterized} by SSI may ^account Saha ^b e ^l n ^ bmtnos ^{of 10} and ^90% oevného.maαiva, 1-15% organic product, 10 to 80% inorganic 4% of the organic state of the composition.

additives and 0.2 to

As solids, grmaite, magnesium bisulfide, thi or boron may be used.

Calcium fluoride from solid mmaiv leads to particularly good results. Z is preferred for graphites of high purity, for example having a purity of more than 96% and an average grain size of at most 300 micrometers. The best results can be achieved with a chart with a purity of 99.5% and a mean particle size of 100 microns.

Organic products which decompose without heat are, for example, alkyl polymers or copolymers; they are homopolymers and copolymers of arylalkenes, alpha, beta unsaturated acids and esters, beta, gamma unsaturated acids and esters, alkenes such as moonooefins, diolefins, etc., vinyls, vinilal alcohol, unsaturated dibasic acids and esters, ie dicarboxylic acids and esters, alkyl esters and acyclic acids and esters.

Alkyeenovými homooolymery and copolymers may be polymeehylmeehaarrlát polyethylene, polystyrene, polybutadiene, polivinilacetát on ^{the L1} ín1loouoioiSt copolymer mmehalmeehaarrl-carboxylate and styrene, a copolymer based meehylenmmehaarylátu and alpha nu thy ^^^ about <Oy1eailylfhalSh, polypropylene, a copolymer of styrene and butadiene, pulyěěfhalmftlakrr1át a copolymer of acetic acid and dibutyl maleate, a copolymer of vinyl acetate and ethylene and polyisobutylene.

These polymers can be used alone or in admixture with each other.

The high temperature grease may contain a number of other ingredients. They are microbiologically active substances. and laughing.

alone

A particular advantage of the present invention is that they are completely free of silicic acid, which is generally in the form of highly disperse silica, and must be used as a stabilizer in formulations containing β ^- phosphates. Silicic acid is undesirable in itself, as it has an opaque effect on the strength and the lifetime of our acids.

In the known formulations, the problem of stabilizing the high temperatures for silicon by replacing silicas with, for example, celluloses or pellets was unresolved. In aqueous suspensions, such mixtures of substances tend to agglomerate and then become unusable. The mixture of the inorganic additives and organic stabilizers according to the invention eliminated these problems.

The process according to the invention uses high temperature lubricants in the form of 5 to 50% by weight of an aqueous dispersion. Suitably, the dispersion has a viscosity of 500 to 15,000 mPas at a temperature of 10 to 30 ° C.

The organic stabilizer contained in the high temperature lubricant may also be sufficient to achieve the required viscosity of the dispersion. However, it is also possible to adjust the viscosity with a thickener or thickener mixture. Among the numerous thickeners, water-soluble polysaccharides, alkylcelluloses, polyvinylpyrrolidone, polyvinyl alcohols, polyacrylates or mineral substances such as clays are preferred.

As mentioned above, high temperature lubricants are generally used in the form of an aqueous dispersion. The aqueous dispersion can be applied to tools and / or workpieces having a temperature of 100 to above 900 ° C. On contact with a hot surface, the water evaporates and a film of uniform thickness is formed.

If the use of the dispersion does not seem expedient, the high temperature lubricant can also be used in powder form. For example, the tool and / or the workpiece is powdered or rolled or pulled with a lubricant.

The lubricants according to the invention are particularly suitable for use at a temperature of about 600 ° C and at a higher temperature. The high temperature stability of the lubricants according to the invention and in particular the stability of the lubricant film is achieved by a substantially high proportion of inorganic additive.

The high temperature lubricants of the present invention are suitable for the lubrication of tools such as a mandrel, mandrel or mandrel, and articles such as a perforated billet or hot-rolled tube in a so-called multiple pipe mill. , Six to eight storeys, on the countertops, on pilgrimage rolling mills, on Assel lines, in units where the perforated billet rolls three rolls with axes offset by 120 ° C, the billet rotates about its axis, in straighteners and in extrusion and extrusion presses.

Examples

Example 1

The high temperature grease is prepared from 70% by weight of water and 30% by weight of the active lubricant components which comprise:

% Crystalline graphite of 96% purity,% insoluble sodium metaphosphate - Maddrell salt,% borax, sodium silicate% - water glass with a molar ratio of SiC ^: Na ₂ O = 3.3% polyethylene powder having a melt index of 70 g / 10 min according to ASTM D 1238-73 T,% alkylcellulose, the percentages being by weight.

* The high temperature lubricant has a viscosity of 1,900 mPas, measured at 20 ° C according to the Epprecht method on Rhéomet 15, Contraves. Said formulation exhibits favorable properties when used at relatively low temperatures of 20 to 250 ° C on titrators or on pilger mill stands. Said spraying device spraying is sprayed onto tools such as mandrels. The coefficient of friction is 0.037.

Example 2

The high temperature grease is prepared in the form of a 70% by weight aqueous dispersion.

The active lubricant components correspond to the formulation of Example 1, but 5% zinc boron is used instead of borax. Lubricant for p ^ t ^ ^ lit: even at high temperatures has a pulse ^lo I 20 C ^ S ^ ¹ zit 2600 mPas. When ^ o ^ ^t to three ovtit.rz · silence or ⁿ and ^p outn KYC ^c: h ^ screws for weighing when the stands umooňuje this improvement maaivo odconos ^! the water deposited layer and improving the adhesion at a temperature between 20 ° C and 250 ° C. The friction coefficient is 0.030.

also

At 1 a

^p ro ^p ^ s oiHtí temperature ^{of 400} and ⁹⁰⁰ ° C @ ntéí.je TX ^P ro ^ s ^^ t hmoonostně those ⁱⁿ the form of 70% aqueous dispersion whose active component consists mmjívovou hmoonootních% crystal-Kehoe graphite mmeefosforečnanu% sodium - Malddreiovz salt% borax, sodium silicate and ^BC i ^e em zltylcelžl0zy ^f f ^ zi-vis the ^p s ²⁰ ° C of ¹⁶⁰⁰ mPas.

^p ^ s ^ e ^p lo of the tools ⁴⁰⁰ to ⁹⁰⁰ ° C oozíw nastro ^says to náásroj ^{characterized} for ^the TV of the ^e naiva uniform film. During the work-up of the article, it is possible to observe a uniform course of the drawing of the rolling current with a friction, which suggests a favorable friction behavior. The friction coefficient is 0.043.

ř í 1 a

Poo ^ is the formulation according přítZadž 3, instead of borax however pouužje same ool> ^Zinc borate viśva NATE ^h o. Vistoz ^ ^p s and ²⁰ ° C of ²¹⁰⁰ mPas. Occurs straight ^from the ^PS learning poorly-adhesion of the film to mozivvvéhv násttoji. The Kovefcielt friction is 0.030.

Pi

and

Table I. Boron compounds. Limiting ranges and moeRelations.

inorganic additive i. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Dec borax% wtc> t. 0,2 25 12 wt. 0,2 25 12 B ₂ O3% wt. 0,2 25 12 % KB ₅ O ₈ .4 H2O% wt. 0,2 25 12 zinc borate % hmoo. 0.2 · 25 12

polyphosphate% hmc> o.

Maddrrel's salt water glass% h * ot

52.3 52.3 52.3 61.8 61.8 39 39 39 46 46 46 '46 54 (SiO ₂ = 21% h ^ oo.)

47.5 '47, 5 47.5 38 38

36 37 38 39 40 41 42

34

ř í

and

Table II. Polyphosphates. Limiting ranges and m-intervals.

inorganic

ingredient no. 16 17 18 19 Dec 20 May 21 borax wt. 25 25 0.2 0.2 25 25 % polyphosphate wt. Maddrell's salt 0.2 98.8 43 % polyphosphate wt. Kurrol's salt 0.2 98.8 43 water glass% wt. (SiO ₂ = 21 wt.%) 74.8 74.8 1 1 32 32

Example 7

Table III. Alkaline silicates. Limiting ranges and intermediate ranges.

inorganic additive no. 22nd 23 24 25 26 27 28 29 30 borax wt. 8 8 8 0.2 0.2 0,2 3 3 3 % polyphosphate wt Maddrell's salt 91 91 91 0.2 0.2 0,2 34,5 34.5 34.5 water glass% wt. (SiO ₂ = 21 wt.%) 1 99.6 62.5 water glass% wt. (SiO ₂ = 47 wt.%) 1 99.6 62.5 potassium water glass% wt. (SiO ₂ = 26 wt.%) 1 99.6 62.5 Examples 8 through 37 According to examples 5, 6 and 7 in advance ready inorganic additives listed under No. 1 to 15,

to 21 and 22 to 30, were processed to lubricants of the following composition: graphite 54 wt%, inorganic additive 26 wt%, polyethylene 18 wt%, and alkylcellulose 2 wt%.

All the lubricants were mixed with water to disperse 30% by weight, solids and 70% water and sprayed onto the hot surface of the tool.

se

The water vaporized to form a film of grease of uniform thickness and high adhesion.

All lubricants according to Examples 8 to 22 (inorganic admixtures) of the desired properties.

23 to 28 (inorganic additives 16 to 21 in the above 22 to 30 in the aforementioned mixture), according to the invention Examples 38. to 61 Table IV. Organic stabilizing additives. Example C. C. C. polyvinyl acetate 38> 46> 1 54 ' polyvinyl alcohol 39 47 55 polysaccharides 40 always 48 ¹ 1 80% wt. 56 polyvinyl butyrate 41 '0,2% wt. 49 57 polyvinylbutyral 42 50 58 polyacrylate 43 51 59 polystyrene 44 52 60 alkylcellulose ⁴⁵ > ⁵³ . 61

(to 29 and to 29 above), 37 (inorganic additives f 40 wt.

* Continuation of Table IV

Example C. C. C. graphite % 55.0 11 33 % polyethylene wt. 18.4 3.7 11.1 inorganic additive No. 11 wt. 26.4 5.3 15.9

The formulations of Examples 38-61 were also treated with water to give a dispersion containing 30% solids and sprayed onto a hot tool. After evaporation of the water, a film was formed on the tool which, in all experiments, met the lubricant properties of the invention in terms of film formation and lubricant stability in all its properties.

Examples 62 to 64

Table V. Polyphosphate. Limit values and intermediate values nu of polyphosphates of the general formula (NaPO ₃ ) _n

Example 62 (NaPOj) _n , , _wherein n = 6 63 (NaPO ₃ ) _{n r} where n = 500 64 (NaPO ₃ ) _n where n = 10,000 to 50,000

The polyphosphate according to the examples, in an amount of 40% by weight, was treated with 30% by weight, borax and 30% by weight, water glass (SiO ₂ = 21%) into three inorganic additives.

A lubricant with the following composition was produced and tested:

graphite 54% by weight, inorganic additive 26% by weight, polyethylene 18% by weight, alkylcellulose 2% by weight

Here again, the result expected for the lubricant according to the invention was found in all cases, as described in the previous cases.

Comparative Example 65 wt.%, Graphite 26 wt.%, Silicic acid, 18 wt.%, Polyethylene and 2 wt.%, The alkylcellulose was premixed dry and then treated with water in an intensive mixer to a solids content of 30% by weight.

A stable suspension was formed which could be easily sprayed with a hot tool spray gun, a hot roll mill mandrel. A firmly adherent and evenly thick film was formed. However, experiments with this lubricant could not be fully carried out, since already 2-3% by weight of the silicic acid in the solid lubricant had an abrasive effect on the equipment and tools and with a silica content of 26% by weight it was feared that serious damage would occur to the equipment. tool.

Comparative Example 66 wt%, graphite, 26 wt%, borax, 18 wt%, polyvinyl alcohol and 2 wt%, alkylcellulose.

As in Example 75, a dry solids mixture was again prepared. In an attempt to produce a 30% by weight aqueous suspension, the solid particles coagulated and further processing of such particles was avoided.

Examples 67 and 68,

In the dry, 54% hiriot was premixed. graphite, 26% by weight, inorganic additives of Example 1, 2% by weight, alkylcellulose - Example 67 - with 18% by weight, polyvinyl alcohol, or - Example 68 - with 18% by weight, polyethylene.

The dry mixture was treated with water in an intensive mixer to a suspension containing 30 wt% solids. The suspensions were homogeneous and stable even after a long time, without sedimentation. The suspensions were sprayed onto a hot mandrel of a rolling mill to produce seamless tubes. The carrier medium - water - was evaporated and a lubricant film of uniform thickness and additionally water resistant was formed on the mandrel.

The energy consumption required to push the mandrel through the rolling stand was noticeably reduced compared to the known lubricants disclosed in SU-PS 632 305. The roughness of the tubes and the wear of the mandrel have significantly improved, especially as compared to silicic acid-containing lubricants, as has been the case so far.

Claims (7)

OBJECT OF THE INVENTION 1. A high-temperature, non-chip hot metal grease comprising a solid lubricant and a thermally decomposed organic product, characterized in that it comprises a solid lubricant, preferably graphite, in an amount of 1 to 90% by weight, an organic product decomposing a total of 1 to 50% hot, further an inorganic additive in an amount of 1 to 80% and an organic stabilizer in an amount of 0.2 to 80%, wherein the inorganic additive is a mixture consisting of a boron compound in an amount of 0.2 to 25% %, polyphosphate 0.2 to 98.8% and alkali silicate 1 to 99.6%, and the organic stabilizer comprises polyvinyl acetate, polyvinyl alcohol, polysaccharides, polyvinyl butyrates, polyvinyl butyrals, polyacrylates, polystyrenes, celluloses, individually or in mixtures with each other. 2. A high-temperature lubricant as claimed in claim 1, wherein the boron compound in the inorganic additive comprises borax, boric acid, boric oxide, boron compound tetrahydrate of the formula KBt-θ or zinc borate, individually or in admixture with each other. 3. High temperature lubricant according to claim 1, wherein the inorganic polyphosphate as an additive contains or Kurrol Maddrell salt of the general formula (NaPO _{3) n} where n is an integer 6-50 000th 4. The high-temperature grease of claim 1 wherein the alkali silicate in the inorganic additive comprises sodium or potassium waterglass with a silica content of 21 to 47% by weight. 5. The high-temperature lubricant of claim 1 wherein the stabilizing agent comprises alkylcelluloses. that as cellulose in organic 6. A high-temperature lubricant according to claim 1, characterized in that it is in the form of 5 to 50% by weight of the aqueous dispersion. High temperature lubricant according to Claims 1 to 6, characterized in that, for use at temperatures up to 350 ° C, it contains an organic product which decomposes wholly hot, in an amount of up to 50% by weight, which quantity when used at a temperature of 600 ° C and above decreases linearly to a maximum of 5% by weight.