CH609728A5

CH609728A5 - High temperature lubricant for the hot-forming of metals

Info

Publication number: CH609728A5
Application number: CH1212774A
Authority: CH
Inventors: Kurt Feneberger; Rolf Gely
Original assignee: Lonza Ag
Priority date: 1974-09-06
Filing date: 1974-09-06
Publication date: 1979-03-15
Also published as: PL101881B1

Abstract

The high temperature lubricant for the hot-forming of metals contains 35 to 90% by weight of graphite, 2 to 60% by weight of homopolymer or copolymer of olefinically unsaturated monomers, 0.2 to 8% by weight of suspending assistant and 2 to 40% by weight of film stabiliser. It is prepared by dry mixing of the individual components. The lubricant is used in the form of an aqueous suspension having a solids content of 5 to 80% by weight. Sodium silicates, boron oxides, phosphates and/or silica may be used as film stabilisers. Such lubricants, which are stable at 900 DEG C, are used, for example, to lubricate the mandrel in the manufacture of seamless tubes, or for roll forming.

Description

  

  
 

**WARNUNG** Anfang DESC Feld konnte Ende CLMS uberlappen **.

 



   PATENTANSPRUCH I
Hochtemperaturschmiermittel für die Warmverformung von Metallen, enthaltend a) 35 bis 90 Gew.-% Graphit b) 2 bis 60   Gew.- %    Homo- oder Copolymerisat von ole finisch ungesättigten Monomeren c) 0,2 bis 8   Gew.- %    Suspensionshilfsmittel d) 2 bis 40   Gew.-O/o    Filmstabilisator.



   PATENTANSPRUCH II
Verfahren zur Herstellung eines Hochtemperaturschmiermittels nach Patentanspruch I, dadurch gekennzeichnet, dass man Graphit, Homo- oder Copolymerisat von olefinisch ungesättigten Monomeren, Suspensionshilfsmittel und Filmstabilisator, wobei die Mengenanteile 35 bis 90 Gew.-% Graphit, 2 bis 60   Gew.-O/o    des Polymerisats, 0,2 bis 8   Gew.- %    Suspensionshilfsmittel und 2 bis 40 Gew.-% Filmstabilisator betragen, trocken vermischt.



   PATENTANSPRUCH III
Verwendung der Mittel gemäss Patentanspruch I in Form von wässrigen Suspensionen mit Feststoffgehalten von 5 bis 80   Ges. %    als Hochtemperaturschmiermittel für die Warmverformung von Metallen.



   UNTERANSPRUCH



   Hochtemperaturschmiermittel gemäss Patentanspruch I, dadurch gekennzeichnet, dass als Filmstabilisatoren Natriumsilikate, Boroxide, Phosphate, Kieselsäure, allein oder in Gemischen untereinander, angewendet werden.



   Gegenstand des Hauptpatentes Nr.   596294    ist ein Hochtemperaturschmiermittel für die Warmverformung von Metallen, enthaltend a) 10 bis 90 Gew.-% Graphit b) 2 bis 45 Gew.-% Homo- oder Copolymerisat von olefi nisch ungesättigten Monomeren c)   0,5 bis    8 Gew.-% Dispergiermittel.



   Besonders geeignet sind derartige Schmiermittel zur Schmierung des Dornes bei der Herstellung von nahtlosen Rohren.



   Bei der Verwendung solcher Hochtemperaturschmiermittel, beispielsweise an Profilwalzen, hat es sich gezeigt, dass der Schmiermittelfilm bei Temperaturen von rund   900 ob    nicht genügend stabil ist.



   Ziel der Erfindung ist es, diesen Nachteil zu vermeiden.



  Erfindungsgemäss wird das durch ein Hochtemperaturschmiermittel, ein Verfahren zu dessen Herstellung und der Verwendung des Mittels gemäss den Patentansprüchen   1    bis III und Unteranspruch erreicht.



   Als Filmstabilisator werden zweckmässig Natriumsilikate, Boroxide, Phosphate, Kieselsäure allein oder in Gemischen untereinander, angewendet.



   Die Homo- oder Copolymerisate von olefinisch ungesättigten Monomeren werden zweckmässig nach dem Emulsions-Polymerisationsverfahren hergestellt. Beispielsweise können die Polymerisate oder Mischpolymerisate von Vinylestern, wie Vinylacetat, Vinylpropionat, Vinyllaurat, von Allylestern, von Mono- oder Diolefinen, wie Äthylen, Butadien, der Acrylsäure und ihren Estern, der Acrylsäure und ihren Estern mit Copolymeren, des Styrols, des Styrols mit Copolymeren und der ungesättigten Dicarbonsäureester, wie Maleinsäureester, angewendet werden.



   Die wässrige, das Schmiermittel enthaltende Suspension wird zweckmässig auf an sich bekannte Weise, wie Aufsprühen oder Aufstreichen, auf das heisse Werkzeug oder Werkstück aufgebracht; dabei verdampft das Wasser und durch Schmelzen bildet das Polymerisat oder Mischpolymerisat einen zähviskosen stabilen Film. Die Filmdicke beträgt zweckmässig 0,05 bis 1,0 mm, vorzugsweise 0,1 bis 0,2 mm. In diesem Film orientieren sich die Graphitteilchen, aufgrund ihrer Struktur, plättchenförmig gleichmässig über die ganze Oberfläche. Zu Beginn des Bearbeitungsprozesses schwimmt das Werkstück gewissermassen auf dem Polymerfilm. Schliesslich brennt das Polymerisat oder Mischpolymerisat sauber ab. Der Abbrand erzeugt ein Gaspolster, das die Trennung zwischen den Reibflächen unterstützt.

  Gleichzeitig ergibt der Graphit eine tragfähige Trenn- und Schmierschicht, die bei lokaler Überbelastung und dadurch verursachtem Abreissen des hydrodynamisch wirkenden Schmelzfilms und besonders bei Spitzentemperaturen während des Prozesses wirksam wird.



   Durch den Abbrand der erfindungsgemässen Zusatzstoffe ist anzunehmen, dass eine Art Schutzatmosphäre zwischen Werkzeug und Werkstück entsteht, die den Abbrand von Graphit bei höheren Temperaturen verzögert.



   Der im erfindungsgemässen Hochtemperaturschmiermittel angewandte Graphit weist zweckmässig eine Korngrösse bis höchstens 300   jtm    und eine Reinheit von wenigstens   96%,    vorzugsweise eine Korngrösse bis 100   ,m    und eine Reinheit von 99,5%, auf.



   Das zur Anwendung gelangende Suspensionshilfsmittel ist ein Polysaccharid, eine Akylcellulose, beispielsweise Methylcellulose, oder ein Alginat. Es kann auch vorteilhaft ein Netzmittel in geringen Mengen zur Suspension zugegeben werden.



   Dem erfindungsgemässen Hochtemperaturschmiermittel können gegebenenfalls noch Zusätze wie mikrobiologische Hilfsstoffe und Oxidationsinhibitoren in geringen Mengen beigemischt werden.



   Das erfindungsgemässe Hochtemperaturschmiermittel kann grundsätzlich zur spanlosen Metallumformung angewendet werden.



   Eine bevorzugte Anwendungsform des erfindungsgemässen Hochtemperaturschmiermittels sind Profilwalzen. Auch bei den dabei auftretenden Temperaturen von 9000C und mehr ist der Schmierfilm stabil und wirksam.



   Beispiel I
Einer wässrigen Dispersion eines Polyisobutylenpolymerisates wird ein Polysaccharid, Kolloid-Kieselsäure, wässrige Natriumsilikatlösung von Be 38/40 und Graphit beigemischt, so dass sich folgende Konzentration ergibt: 20% Graphit
5% Polyisobutylenpolymerisat
4% Kolloid-Kieselsäure 10% Natriumsilikatlösung
2% Polysaccharid 59% Wasser.



   Diese Suspension kann auch das Werkstück oder Formgut aufgetragen werden. Die Filmstabilisatormischung ergibt einen gleichmässigen, optimal wirkenden Schmierfilm auch bei den üblichen angewendeten Umformungstemperaturen, beispielsweise'beim Profilwalzen, von bis über   900"C.     

 

   Beispiel 2



   Die folgenden Komponenten werden in pulvriger Form trocken miteinander innig vermischt oder vermahlen:   59%    Graphit 19% Acryl-Styrol, Mischpolymerisat
6% Kolloid-Kieselsäure 13% Natriumsilikat
3% Polysaccharid.



   Am Anwendungsort, kurz vor dem Gebrauch, wird das Trockengemisch in die gleiche Menge Wasser eingeführt, so dass eine Suspension mit 50% Feststoffgehalt entsteht. Die Suspension ist versprühbar und wird auf das Werkstück und/ oder Werkzeug aufgebracht, wobei das Wasser auf der heissen Oberfläche verdampft und das Hochtemperaturschmiermittel bei der Verarbeitung wirksam wird. Der Schmierfilm ist auch bei hohen Temperaturen durch die Anwendung des Filmstabilisators äusserst stabil. 



  
 

** WARNING ** Beginning of DESC field could overlap end of CLMS **.

 



   PATENT CLAIM I
High-temperature lubricant for the hot forming of metals, containing a) 35 to 90% by weight of graphite b) 2 to 60% by weight of homo- or copolymers of olefinically unsaturated monomers c) 0.2 to 8% by weight of suspension aids d) 2 to 40% by weight film stabilizer.



   PATENT CLAIM II
Process for the production of a high-temperature lubricant according to claim 1, characterized in that graphite, homo- or copolymer of olefinically unsaturated monomers, suspension aid and film stabilizer, the proportions being 35 to 90% by weight of graphite, 2 to 60% by weight of graphite, 2 to 60% by weight of the polymer, 0.2 to 8% by weight of suspension aid and 2 to 40% by weight of film stabilizer, mixed dry.



   PATENT CLAIM III
Use of the agent according to claim I in the form of aqueous suspensions with solids contents of 5 to 80% by weight as high-temperature lubricants for the hot forming of metals.



   SUBClaim



   High-temperature lubricant according to patent claim 1, characterized in that sodium silicates, boron oxides, phosphates, silicic acid, alone or in mixtures with one another, are used as film stabilizers.



   The main patent no. 596294 is a high-temperature lubricant for the hot forming of metals, containing a) 10 to 90 wt .-% graphite b) 2 to 45 wt .-% homo- or copolymer of olefinically unsaturated monomers c) 0.5 to 8% by weight dispersant.



   Such lubricants are particularly suitable for lubricating the mandrel in the production of seamless tubes.



   When using such high-temperature lubricants, for example on profiled rollers, it has been shown that the lubricant film is not sufficiently stable at temperatures of around 900.



   The aim of the invention is to avoid this disadvantage.



  According to the invention, this is achieved by a high-temperature lubricant, a method for its production and the use of the agent according to claims 1 to III and the dependent claims.



   Sodium silicates, boron oxides, phosphates, silicic acid alone or in mixtures with one another are expediently used as film stabilizers.



   The homo- or copolymers of olefinically unsaturated monomers are expediently prepared by the emulsion polymerization process. For example, the polymers or copolymers of vinyl esters, such as vinyl acetate, vinyl propionate, vinyl laurate, of allyl esters, of mono- or diolefins, such as ethylene, butadiene, acrylic acid and its esters, acrylic acid and its esters with copolymers, of styrene, of styrene with Copolymers and the unsaturated dicarboxylic acid esters, such as maleic acid esters, are used.



   The aqueous suspension containing the lubricant is expediently applied to the hot tool or workpiece in a manner known per se, such as spraying or brushing on; the water evaporates and the polymer or mixed polymer melts to form a viscous stable film. The film thickness is expediently 0.05 to 1.0 mm, preferably 0.1 to 0.2 mm. In this film, due to their structure, the graphite particles are evenly oriented in platelets over the entire surface. At the beginning of the machining process, the workpiece floats to a certain extent on the polymer film. Finally, the polymer or mixed polymer burns off cleanly. The burn creates a gas cushion that supports the separation between the friction surfaces.

  At the same time, the graphite results in a stable separating and lubricating layer, which becomes effective in the event of local overloading and the resulting tear-off of the hydrodynamically acting melt film and especially at peak temperatures during the process.



   As a result of the burn-off of the additives according to the invention, it can be assumed that a kind of protective atmosphere is created between the tool and the workpiece, which delays the burn-off of graphite at higher temperatures.



   The graphite used in the high-temperature lubricant according to the invention expediently has a grain size of up to at most 300 μm and a purity of at least 96%, preferably a grain size of up to 100 μm and a purity of 99.5%.



   The suspension aid used is a polysaccharide, an alkyl cellulose, for example methyl cellulose, or an alginate. A wetting agent can also advantageously be added to the suspension in small amounts.



   Additives such as microbiological auxiliaries and oxidation inhibitors can optionally also be added in small amounts to the high-temperature lubricant according to the invention.



   The high-temperature lubricant according to the invention can in principle be used for non-cutting metal forming.



   A preferred form of application of the high-temperature lubricant according to the invention are profile rollers. The lubricating film is stable and effective even at the temperatures of 9000C and more that occur.



   Example I.
A polysaccharide, colloidal silica, aqueous sodium silicate solution of Be 38/40 and graphite are added to an aqueous dispersion of a polyisobutylene polymer, so that the following concentration results: 20% graphite
5% polyisobutylene polymer
4% colloidal silica 10% sodium silicate solution
2% polysaccharide 59% water.



   This suspension can also be applied to the workpiece or material to be molded. The film stabilizer mixture results in a uniform, optimally acting lubricating film even at the usual forming temperatures used, for example in profile rolling, of up to over 900.degree.

 

   Example 2



   The following components are intimately mixed or ground with one another in dry powder form: 59% graphite 19% acrylic-styrene, copolymer
6% colloidal silica 13% sodium silicate
3% polysaccharide.



   At the application site, shortly before use, the dry mixture is introduced into the same amount of water, so that a suspension with 50% solids content is formed. The suspension can be sprayed and is applied to the workpiece and / or tool, the water evaporating on the hot surface and the high-temperature lubricant becoming effective during processing. The lubricating film is extremely stable even at high temperatures thanks to the use of the film stabilizer.

Claims

PATENT CLAIM I High-temperature lubricant for the hot forming of metals, containing a) 35 to 90% by weight of graphite b) 2 to 60% by weight of homo- or copolymers of olefinically unsaturated monomers c) 0.2 to 8% by weight of suspension aids d) 2 to 40% by weight film stabilizer.

PATENT CLAIM II Process for the production of a high-temperature lubricant according to claim 1, characterized in that graphite, homo- or copolymer of olefinically unsaturated monomers, suspension aid and film stabilizer, the proportions being 35 to 90% by weight of graphite, 2 to 60% by weight of graphite, 2 to 60% by weight of the polymer, 0.2 to 8% by weight of suspension aid and 2 to 40% by weight of film stabilizer, mixed dry.

PATENT CLAIM III Use of the agent according to claim I in the form of aqueous suspensions with solids contents of 5 to 80% by weight as high-temperature lubricants for the hot forming of metals.

SUBClaim

High-temperature lubricant according to patent claim 1, characterized in that sodium silicates, boron oxides, phosphates, silicic acid, alone or in mixtures with one another, are used as film stabilizers.

The main patent no. 596294 is a high-temperature lubricant for the hot forming of metals, containing a) 10 to 90 wt .-% graphite b) 2 to 45 wt .-% homo- or copolymer of olefinically unsaturated monomers c) 0.5 to 8% by weight dispersant.

Such lubricants are particularly suitable for lubricating the mandrel in the production of seamless tubes.

When using such high-temperature lubricants, for example on profiled rollers, it has been shown that the lubricant film is not sufficiently stable at temperatures of around 900.

The aim of the invention is to avoid this disadvantage.

According to the invention, this is achieved by a high-temperature lubricant, a method for its production and the use of the agent according to claims 1 to III and the dependent claims.

Sodium silicates, boron oxides, phosphates, silicic acid alone or in mixtures with one another are expediently used as film stabilizers.

The homo- or copolymers of olefinically unsaturated monomers are expediently prepared by the emulsion polymerization process. For example, the polymers or copolymers of vinyl esters, such as vinyl acetate, vinyl propionate, vinyl laurate, of allyl esters, of mono- or diolefins, such as ethylene, butadiene, acrylic acid and its esters, acrylic acid and its esters with copolymers, of styrene, of styrene with Copolymers and the unsaturated dicarboxylic acid esters, such as maleic acid esters, are used.

The aqueous suspension containing the lubricant is expediently applied to the hot tool or workpiece in a manner known per se, such as spraying or brushing on; the water evaporates and the polymer or mixed polymer melts to form a viscous stable film. The film thickness is expediently 0.05 to 1.0 mm, preferably 0.1 to 0.2 mm. In this film, due to their structure, the graphite particles are evenly oriented in platelets over the entire surface. At the beginning of the machining process, the workpiece floats to a certain extent on the polymer film. Finally, the polymer or mixed polymer burns off cleanly. The burn creates a gas cushion that supports the separation between the friction surfaces.

At the same time, the graphite results in a stable separating and lubricating layer, which becomes effective in the event of local overloading and the resulting tear-off of the hydrodynamically acting melt film and especially at peak temperatures during the process.

As a result of the burn-off of the additives according to the invention, it can be assumed that a kind of protective atmosphere is created between the tool and the workpiece, which delays the burn-off of graphite at higher temperatures.

The graphite used in the high-temperature lubricant according to the invention expediently has a grain size of up to at most 300 μm and a purity of at least 96%, preferably a grain size of up to 100 μm and a purity of 99.5%.

The suspension aid used is a polysaccharide, an alkyl cellulose, for example methyl cellulose, or an alginate. A wetting agent can also advantageously be added to the suspension in small amounts.

Additives such as microbiological auxiliaries and oxidation inhibitors can optionally also be added in small amounts to the high-temperature lubricant according to the invention.

The high-temperature lubricant according to the invention can in principle be used for non-cutting metal forming.

A preferred form of application of the high-temperature lubricant according to the invention are profile rollers. The lubricating film is stable and effective even at the temperatures of 9000C and more that occur.

Example I. A polysaccharide, colloidal silica, aqueous sodium silicate solution of Be 38/40 and graphite are added to an aqueous dispersion of a polyisobutylene polymer, so that the following concentration results: 20% graphite 5% polyisobutylene polymer 4% colloidal silica 10% sodium silicate solution 2% polysaccharide 59% water.

This suspension can also be applied to the workpiece or material to be molded. The film stabilizer mixture results in a uniform, optimally acting lubricating film even at the usual forming temperatures used, for example in profile rolling, of up to over 900.degree. ** WARNING ** End of CLMS field could overlap beginning of DESC **.