DE1794240C3 - Method of mechanically working a hot, deformable metal - Google Patents

Description

Plate and continuous potting operations have created an urgent need for hot working lubricants to minimize surface damage in finished products and to extend the life of the work and counter rolls used to roll the steel. The difficulty in the creation of suitable lubricants will be apparent when one considers that continuous When rolling operations are carried out at temperatures in the range of about 870-1150 ⁰ C.

In a typical continuous chair rolling mill, the line may consist of a scale breaker roughing stand, four or more four-roll roughing stands, a finishing scale breaker, and 6 or more tandem four-roll finishing stands. Driven roller table rollers transport the steel from stand to stand. StahlpJatten are fed to the track at temperatures in the range from about 1093 to 1315 ⁰ C. The steel plates are rolled to the desired thickness and the rolled product is cut into desired lengths or wound in one piece. The four-roll finishing stands each consist of a pair of driven work rolls, between which the steel is machined and its thickness reduced. The work rolls work together with backup or pressure rolls, which provide the work rolls with additional support and ensure a greater reduction per pass. A description of such a continuous hot strip mill can be found in "The Making, Shaping and Treating of Steel", 8th edition, pp. 894-902 (1964), published by US Steel Corp.

The aim of the invention was to provide a method for mechanical processing of malleable metals at high temperatures using a synthetic lubricant. A lubricant should be used in this procedure which is suitable for the shaping of steel products (plates, rods, strips, sheets, beams, Bars, rails) and especially for continuous hot strip mills. Your suitability should also focus on the hot processing of copper, brass, aluminum, magnesium and titanium extend.

The subject of the invention is a method for the mechanical processing of a hot, deformable metal using a synthetic liquid organic lubricant in which the following Procedural measures are carried out:

1) heating this metal to a temperature at which it is in a deformable state, in particular to a temperature of 870 to 1315 ° C,

2) Applying and evenly distributing a liquid consisting of fatty acid polyol ester Lubricant, its polyol component 2 to 12 hydroxyl groups and its fatty acid component Has 12 to 22 carbon atoms on the machining surface a machining element before this with the heated deformable metal under a certain machining pressure comes into contact to a separating medium on the contact surfaces of this machining surface and to create the surface of this metal

which is characterized in that a trimethylolethane-tritallow fatty acid ester is used as the liquid lubricant, the tetraoleate of pentaerythritol, the trimethylolpropane trital oil ester, the glyccrine tritali oil ester Di-pentaerythritol polycoconut fatty acid esters or mixtures thereof, or one with fatty acids modified alkyd resin used.

According to the invention a method for the mechanical processing of deformable metals, such as

ίο z. B. steel, created in which the metal is heated to a deformable state and by means of a Arbeitselementcs with a working surface acting on the metal, a working pressure is exerted on the surface of the metal, one of the

is the synthetic, organic, liquid work surface Lubricant is supplied and evenly distributed on it before the work surface is touched with the heated deformable metal brings into contact to a separating medium at the contact surface

ao between the work surface and the surface of the To create metal.

The invention provides synthetic lubricants which are effective in hot strip steel strip operations can be used. The lubricants will

as in the liquid state or in the form of aqueous Dispersions on the metalworking elements, such as. B. the work rolls of a steel strip hot rolling mill, applied by means of any available act that provides an even, continuous

3 »natural film is produced on the surface of the work rolls. The liquid lubricant can with With the help of a spray device on both the upper and the lower counter roller on the outlet side of the Scaffolding are applied so that the lubricant in the point of engagement between the working and the counter roll is transported. At this point the lubricant will be uniform across the surfaces the work and the counter roll distributed. The lubricant can be applied to one or more of the scaffolds Finished route can be applied. The application of the lubricant is generally to the fulcrum frames the finishing line or those stands that are most subject to roll wear, limited. If desired, the lubricant can also be applied to the roughing or roughing rollers will. In the actual rolling operations, it has proven to be advantageous to place the work rolls in front of them the entry of a rod into the special framework to which the lubricant is to be applied to keep from lubricants. When the lubricant is present on the work rolls, the The rod is not properly gripped and the steel tape may stick to the roller because of the coefficient of friction is reduced by the application of a lubricant and the roller to slack tends.

The esters of fatty acids and polyols can be prepared by known methods, e.g. B. by Heating in a still with direct thermal fusing of the components or without catalysts. Such catalysts can be acids, Lewis acids, metal oxides, metal hydroxides and the like. The water is then removed in a suitable manner. The azeotropic removal of the water of reaction, the distillation of the water of reaction in vacuo and the removal of the water of reaction by means of Gas transmission can be used. The ester products can be used directly in an anhydrous state

5 6

"; or in the form of an aqueous dispersion with the aid of suitable

Ά Devices as lubricants for hot metal lubricants 3

'- ■ edits are applied. Mixtures of

Esters can be used, or they can be distilled with tall oil 855 parts H mineral oil fractions or other solvents for 5 trimethylolpropane 135 parts

'. ^: special applications dilute »earth. In addition, trifluoride ether 0.1 part

separation aids, such as silica, can be finer

Clay, fly ash, Fuller's earth, graphite, talc, and the like. This mixture was heated to about 163 ° C

;. '· Applied in conjunction with the lubricants and kept at this temperature while the

especially if it was distilled off for metal casting and water of reaction. After 52 parts

Ironwork can be used. Water had been removed, being towards the end of the In addition to the above-mentioned polyol fatty acid ester reaction, a vacuum was applied, this resulted

can also produce alkyd resins modified with fatty acids as a yellow oil, which is essentially

be used as a lubricant. These include borrowed from the trimethylolpropane trital oil ester

Condensation products from fatty acids, normal 15
wise mixtures thereof, one or more poly-

ols and a dicarboxylic acid. About this dicarbon lubricant 4
■ acids include phthalic acid, isophthalic acid, tere-

phthalic acid, maleic acid, fumaric acid, tetrahydro tall oil top fractions 1000 parts

; phthalic acid, succinic acid, adipic acid, azelaic * o glycerin 92 parts

acid, sebacic acid and condensation products of

Maleic anhydride with different masses, such as. This mixture was heated to about 260 to 274 ⁰ C z. B. Rosin. The compounds or products mentioned can be used to distill off the water. According to a lubricant in connection with mineral oils »5 which have formed about 50 ml of water of reaction, '■■■' ■ and / or solvents can be applied. With the reaction was stopped, and a dark-fatty acid-modified alkyd resin can result in water-brown liquid, which consisted essentially of glycerol tritallol ester or other solvents as a diluent,
use.

In order to explain the invention, 30 lubricants 5
I. the compositions and the manufacture

Another useful lubricant for coconut continuous fatty acids 1000 parts

;. Strip steel hot rolling mill described (Die parts Dipentaerythrit 254 parts

ί · '■ of the components in the examples are weight

; ; parts.) 35 This mixture was ^{heated to about 163 0} C until

- 85 to 90 parts of water of reaction have been removed

^: Were lubricants. The reaction product was somewhat viscous

;; yellow-brown liquid, consisting essentially of di-

1 tallow fatty acids consisted of 840 parts of pentaerythritol polycoconut acid ester.

: j Trimethylolethane 120 parts 40 According to the invention it was found that the poly

'■ olesters of long-chain fatty acids (the smallest chain

These components were mixed and heated to a length of 16 carbon atoms) extremely suitable lubricants

! while through the bottom of the reaction flask are medium luv steel hot rolling mills when going with

_: Nitrogen was passed through to remove the reaction fatty acid esters of lesser chain length or the bis-

; remove water. While stirring the mixture 45 compares well-known polyethylene glycol esters.
f; was at temperatures of about 260 to 274 ° C

h worked. After removing about 54 parts of water (1) Auto-ignition temperatures are higher,

':' the implementation was canceled. and the tendency to evaporate is less for

|: The product was a brown liquid that predicted the higher molecular weight esters than the lower esters.

iy mainly from trimethylolethane-tritallow fatty acid ester be 50 (2) The presence of an excessively high oxygen

U stood. content with free active hydrogen is original

% matter of an almost explosive flammability.

\ Lubricant 2 (3) Easily flammable materials are the cause

for large volumes of dense smoke, which

oleic acid 1120 parts 55 obstructs the view (of working in the overhead crane),

lh pentaerythritol 136 parts or for asphyxiation vapors.

\ i Toluenesulfonic acid 0.1 part

H xylene 50 parts The need for relatively low evaporation

If there is a tendency to use and relatively poor flammability! This mixture became clear at temperatures of up to 60, if the temperatures occurring during tub rolling from [I to about 204 ° C., while the water of reaction steel is taken into account, are taken into account. si was removed by azeotropic distillation, whereby the slabs can temperatures between 870, the xylene layer was continuously recycled. and 126o have ⁰ C. At this temperature, heat is transferred to the processing rollers after 70 parts of water of reaction have been removed, which were last, the xylene was evaporated in vacuo, 65 lent to be coated with lubricants, leaving a yellow liquid product that is too volatile if the lubricant is too volatile the presence of which, essentially from the tetraoleate of pentaerythritol, is too short-lived for its function to exist. could meet. If the product burns down quickly,

its concentration drops so rapidly that it does not act as a lubricant.

This is evident from the following insurance material emerged.

A - Vapor pressure glycerides ⁰ C

Triglyceride

0.05mm pressure

0.001mm print

Tricaprine (C 10) 213 ° C 159 ° C Trilaurin (C12) 244 ⁰ C 188 ⁰ C. Trimyristine (C 14) 275 ⁰ C 216 ° C Tripalmitin 298 ° C 239 ⁰ C Tristearin (C 18) 313 ° C 253 ° C Soybean oil 308 ° C 254 ⁰ C B - flammability

The smoke points, flash points, fire points and self-ignition of fats correspond to those under A. values given in the table. The higher the materials boil, the less they tend to burn and for steam generation. This applies either to the material itself or to the burning of the fat.

Materials are rated with regard to their relative tendency to burn as follows:

A pyroceram topped hot plate was brought to 538 ° C. Then a carefully aligned one Drops (0.1 ml) were dropped on the surface and observed. The results are below S in summary:

product

Smoke and fire

ίο red oil esters from
Pentaerythritol
Red oil ester of
Trimethylol propane

Red oil ester of glycerine
_ ...
Purified

high viscosity white oil

Diethylene glycol

tall oil ester

ao polyethylene glycol tall oil ester

Tall oil ester
oleic acid ester
"Naphthenic acid oil

Pluronis L-64
Igepal CO 630

smokes white -

No fires

smokes white -

No fires

Fire, black smoke Fire, black smoke

Fire, black smoke. Fire, black smoke

Fire, black smoke Fire, black smoke

thick black

smoke

immediately flame

immediately flame

926 ° C reaction

0.1 ml oil, heated from ambient temperatures to 926 ° C and 705 ⁰ C.

oil Seconds to Hamm formation Smoke (see code) 705 ° C 926 ° C 705 ° C 926 ° C 3 Soybean oil esters 12-5-14 45 I-A 3 oleic acid 12th 49 2 3 Tall oil 12th 40 2 3 Distilled tall oil 14th 45 2-3 - Glyceryl trioleate 13.5 - 4th 4th High viscosity white oil 6th 20th 3-4

Code (roughness rating) 0 no black smoke

1 dark clean

2 black, no carbon black 3-schwaiz - small soot particles

4 schwatz - large soot particles and flakes

boiling point
Dear one

From this it can be seen that C16- and C 18 esters are desirable; min sees that penta

Boiling point at atmospheric pressure,. . , ,,.

on the assumption that no decomposition takes place "erythntester against evaporation even more resistant

are.

Fatty acid, length

Glycerides - estimated boiling point

Pentaerythritol esters - estimated boiling point

C8
ClO
C 12
C 14
C 16
C 18

265 ° C
343 ^e C
385 ° C
438 ° C
482 ° C
521 ³ C

365 ° C 426 ° C 482 ° C 538 ° C 594 ° C 638 ⁰ C.

The flash points of substances are also an indication of the durability at elevated temperatures

Connection "C

Butyl stearate Diglycol oleate Diglycol stearate Di-2-ethylhexyl succinate Glycryl trioleate

Primetalg

188
143
143
157
271
269

The higher molecular weight esters have less tendency to burn than the lower esters.

The following guidelines can be derived from this:

1. Products should contain as many ester groups as possible without an excess of oxygen in the system

2. Use of fatty acids C 16 and higher Fatty acids

3. Use of esters instead of compounds with free hydroxyl groups.

The lubricants according to the invention are for the continuous production of hot-rolled flat steel plates, Steel strips, sheets and rods, as well as other metals and alloys, such as Copper, brass, aluminum, magnesium, titanium, etc., useful. The lubricant! are also for other hot metal processing methods such as extrusion, forming, forging, continuous Potting, etc., usable. The lubricants have the property of both the surface of the To wet work elements as well as that of the metal surface to be processed and to rest on them to distribute, thus creating a separating medium between the surface of the work elements and the metal to be processed.

According to the present invention, special lubricants with predetermined viscosities, pour points and lubricating properties used for all types of hot rolling operations. These lubricants ensure excellent wetting of the surfaces of the hot rolls and form one Film that remains on the surface of the rollers and creates a separating buffer zone, whereby the Oxide formation or sticking to the surface of the work and counter roll is prevented. The lubricants perform their lubricating function and then melt away, leaving behind residues is avoided on the strip surface at the end of the rolling operation. The molecular film remains on the strip long enough to allow a certain amount of lubricant to be applied to the subsequent one Transfer scaffolding.

The invention offers numerous advantages and leads to a reduction in maintenance costs for the Equipment of strip rolling mills.

The use of the lubricants according to the invention for the machining of steel rods. Temperatures in the range from about 870 to 1150 ⁰ C offers the following advantages:
. ¹ ^ P ^ic Lifespan of both the object and the

^Ar . ^be ' ^tswa ^ ^e " ^Wlrd Λ *.' ¹ ™ * "· ^Major ^ ^{d! S today} '' ^s increased rolling speeds is greater ^ M ??« «« increased roll wear generated

The rolling duration is reduced by shorter

^w ? ^c ! « ^cl " ^Η ^ reduced, whereby a

« ^{Rh <} * ^te production results. The welding, of

Scale on the roll surfaces is reduced

gert.

3. The quality of the hot rolled strips, e.g. B.

its surface quality is improved. the enormous friction that occurs between the belt and the work rolls leads to cracks or others Damage in the metal surface, which is reduced by the lubricant.

"4. The tapes are better stained (by lowering of carried scale, rolled-in scale, etc.). With less rolled-in scale the pickling speeds can be increased.

5. The amount of from the roller surface when »5 pulling off a roller used (work or counter roller) metal to be removed is reduced. This results in a greater production per Set of rollers.

6. Lower loads on the hot rolls are made possible (lower power consumption).

7. Saving of man-hours in mechanical work through less frequent roll changes. (Assembly and disassembly of work rolls and support bearings !!.)

8. Work roll inventory required because of frequent changes may be reduced will.

9. Lower acid consumption during pickling. It will have high product quality and overall Furthermore, a higher yield is achieved due to the reduced damage to the hot rolls. One porous surface caused by worn work rolls is ingress much more exposed to impurities, which ultimately lead to rolled-in dirt. The costs for the roll renewals are thus considerably reduced

Claims (2)

Patent claims: 1. Method of mechanically working a hot ductile metal using a synthetic, liquid, organic lubricant in which the following procedural measures be performed: 1) heating this metal to a temperature at which it is in a malleable state is located, in particular at a temperature of 870 to 1315 ° C, 2) Applying and evenly distributing a liquid consisting of fatty acid polyol ester Lubricant, its polyol component 2 to 12 hydroxyl groups and its fatty acid component Has 12 to 22 carbon atoms on the machining surface of a machining element, before these come into contact with the heated deformable metal under a certain processing pressure comes to a separating medium on the contact surfaces of this machining surface and to create the surface of this metal characterized in that the liquid lubricant used is a trimethylolethane-tritallow fatty acid ester, the tetraoleate of pentaerythritol, the trimethylolpropane trital oil ester, the Glycerine trital oil ester, the di-pentaerythritol poly coconut fatty acid ester or mixtures thereof, or an alkyd resin modified with fatty acids is used. 2. The method according to claim 1, characterized in that that the lubricant is used in the form of an aqueous dispersion. The invention relates to a method for mechanically working a hot, deformable metal using a synthetic liquid organic lubricant in which the following Procedural measures are carried out: 1) heating said metal to a temperature at which it is in a deformable state, in particular to a temperature of 870 ° to 1315 ⁰ C, 2) Applying and evenly distributing a liquid consisting of fatty acid polyol ester Lubricant, its polyol component 2 to 12 hydroxyl groups and its fatty acid component Has 12 to 22 carbon atoms on the machining surface of a machining element, before this with the heated deformable metal under a certain processing pressure comes into contact to a separating medium on the contact surfaces of this machining surface and the surface of this metal. Modern lubricants often have to operate at temperatures above about 204 ° C, which is where the known mineral oils deteriorate rapidly, corrosive, volatile and therefore exposed to stress Purpose useless wo-rjen. The available synthetic base oils, i ". Sier, ethers, silicones or hydrocarbon po'y-k ', s ·'. '.:, subject under these extreme conditions often result in thermal or oxidative degradation, which leads to the formation of Sludge and deposits, to change viscosity, discoloration, increased corrosion effect and other undesirable changes. Try to remedy these defects with the help of the usual Measure-S paralyze off are due to the extreme Working conditions remained unsuccessful; z. B. the addition of an antioxidant can be a cause increased corrosion or the addition of an anti-wear agent reduce the stability. Try, Eliminating the newly emerged defects often creates new problems by causation increased sludge formation, etc. Lubricants for metalworking are simply known. In AT-PS 2 60 403 the IS use of mixed star straight-chain saturated Fatty acids with 6-14 carbon atoms and polyhydric alcohols in mineral oil emulsions as lubricants proposed for cold rolling of sheet metal. Aqueous emulsions for non-cutting cold forming of metals include sulfated esters of higher fatty acids with at least 12 carbon atoms and monohydric or polyhydric alcohols (DE-PS 9 50 591) and condensation products from neutral oils, fatty acids or fatty alcohols with at least 12 carbon atoms «5 men and non-ionic water-solubilizing agents Connections (DE-AS 10 43561). The aqueous lubricating emulsions for cold rolling sheet metal consist according to DE-AS 12 57 335 of palm oil, BaumwoUsamenöl, di-n-butyl sebacate, n-butyl stearate. 3 "> 2-ethylhexyl phthalate or dioctyl sebacate as a lubricating oil in addition to a certain proportion of alkali chromate, dichromate or chromic acid and polyalkylene glycol monophenyl ether derivative. Tallow and rapeseed oil form the fat base of the aqueous emulsions for cold rolling according to DE-AS 10 53 701, with monoglycerol fatty acid ester being an additional component Fatty components in connection with an emulsifier for the fat and phosphoric acid are contained in the lubricants of DE-AS 11 03 498 in the production of bare metal pipes from ferrous materials, in particular steel, by non-cutting cold forming of pipe blanks or pre-drawn pipes.
The use of certain polyalkylene glycols or their esters and ethers in the form of aqueous dispersions as lubricants for metalworking has also been proposed many times (see CH-PS 3 95 408, DE-PS 9 77 489). The oil-free, aqueous lubricating, cutting and cooling liquid for metalworking according to the known patent application N 6545 IVd / 23c also has a surface-active, optionally etherified or esterified polyalkylene polyol of a certain composition. A lubricating mixture, especially for rolling, milling and drilling metal, contains according to CH-PS 3 96 276 a smaller amount of a soluble polyoxyalkylene with a negative solubility coefficient, the lubricant for rolling metal according to AT-PS 2 15 580 a minor amount of a diester of a polyoxyalkylene glycol. Further lubricants containing polyalkylene glycol are proposed in DE-AS 11 04 104, the known German patent application C 11 447 IVc / 23c, DE-AS 10 52 042, among others. Satisfactory lubricants for hot rolling steel products have not yet been available been. The construction of today's high-speed hot strip mills, the larger steel