DD267030A1 - UNRESERVED, FIRE-RESISTANT WEARING MATERIAL FOR SLIDING LATCHES - Google Patents

Abstract

The invention relates to an unfired refractory wear material for Schieberverschluesse of metal melt containing containers and aggregates, which finds its use in the pouring without pouring from ladles and distributors, taps and plasma and Elektrooefen. The object of the invention is to develop an unfired, refractory wear material for Schieberverschluesse of metal melt containing containers and aggregates, which is less energy consuming, uncomplicated and environmentally friendly to produce and the requirements for erosion and abrasion resistance and temperature change and chemical resistance comparatively better. According to the invention, the object is achieved in that the refractory component of the wear material is bound by a carbon bond attributable to the use of non-meltable polymers and graphite.

Description

Field of application of the invention

The invention relates to an unfired refractory wear material for slide closures of molten metal containing containers and assemblies, which finds its use in non-stop pouring from ladles and distributors, taps Gowie plasma and electric furnaces.

characteristic of the known technical solutions

Containers and aggregates for receiving and producing molten metal, in particular steel, have in their Godeni ^ il for discharging the molten metal on a Ausfit ßöffnung, which is often completed by a parallel to the bottom of the container, or unit movable slide closure.

The refractory Verschteißmaterialien this slide fasteners, which also include the upstream and downstream sleeves in addition to the mutually movable slide plates are particularly heavily subjected to erosion and temperature changes.

For this reason, very different Vetschlelßmaterlalien have already been tested in practice and described in the literature.

Bishor it was customary, such wear materials for slide fasteners of high alumina materials win Tabulartonerde or corundum with or without additives of z. B. zirconium, chromium or Siliclurr.-Vovblndimgon or magnesia produce. From diosen materials were pressed under the use of the respective binder by high pressures, the corresponding moldings. Subsequently, to produce the ceramic bond a Hochtornperaturbrend to achieve the required for further treatment and use strength and high resistance to the cast jet in the pass region through the slide closure.

The disadvantage here was the low thermal shock resistance, especially in the case of magnesia products, of the burned-off sealing material.

To further Verringnrung of corrosion and in order to increase the lubricity of the Schleborplatten, the wear materials are impregnated with tar, pitch or resins and these vercrackt at 250 to 600 ⁰ C. In all cases, tar impregnation has been successful, as there is a reduction in the binding phase with corresponding vascularity

Another disadvantage of the secondary introduction of carbon by impregnation with pitch, tar, etc. in the wear material is the relatively low Porenauafüllungsgrad after the subsequent annealing process.

In DE-AS 260334V. describes a stone slab for a closure slide in which carbon is primarily introduced into the structure of the slab by the incorporation of 2-10% graphite into the molding compound and a subsequent ceramic fire in a reducing environment.

With the flagstones thus manufactured, I had a decreased consistent displacement resistance as well as an improved plant life span. A disadvantage is the ceramic fire associated with high costs and the need for a further increase in the durability of the flagstone repeated impregnation with pitch or tar.

Only by a number of further reducing fires corresponding to the number of impregnations is it possible to expel the volatiles and to fill the pore space with carbon.

Aue the DE-PS 3307193 a slide plate is known, which consists of a chemically bonded unfired body with carbon content, ζ.B. in the form of graphite admixed with 2 to 30% of the main refractory raw materials and consisting of a highly heat-resistant ceramic substitution ceramic insert. '

Dlose invention thus leaves the development direction of the tarry impregnation. The chemically bound basic body shows

a sufficient abrasion resistance and a higher compared to ceramic bonded bodies

TemperaturwechselbestAndigkelt. A disadvantage is the relatively high porosity of 12-16%. This promotes decarburization in the Cinsatzfall, resulting in a Deterioration of the use behavior with steel contact, in case of use as contact wear material

leads. Also unfavorable is the complicated and costly Herote'lungsverfahren the slide plate.

The contact point between the ceramic insert and the chemically bonded body also provides a Weak point in the structure of the product. Object of the invention

ZIoI dor invention It is to provide an unburned refractory wear material for Schlebereverechtüsse of molten metal containing containers and aggregates, which can be produced environmentally friendly with mlnlmalom energy · and production costs and has an improved Betriebsvorhalten.

Explanation of the essence of the invention The invention has the object, an unfired refractory material for slide closures of molten metal

containing containers and aggregates, which is low energy consuming, uncomplicated and environmentally friendlyl'drstellbar and the requirements of erosion and abrasion resistance and temperature change and chemical

Resistance comparatively booser is enough, En'indungsgemäß the object is achieved in that the refractory component of Vcrschleißmaterlalf by a on the Use of nleichschmolrbaren polymers and graphite attributable Kohlenstoffblndung are bound. The carbon bond of the Verechlelßmateriais can be hoofbouen at Behandlungslunemperaturemperatures up to 1000 ⁰ C. According to the Einauücharakteristik the refractory Verechleißmaterialian the formation of the carbon bond can also

during the first heating up to operating temperature so that the heat treatment temperature of the products in the production process only needs to be maintained at a maximum of 200 ° C.

As a binder of the pressmase are non-meltable polymers, preferably phenol formaldehyde · and / or furan resins

added, wherein a proportion of the resin component is used in powder form.

The advantage of incorporating the refractory components and the carbon species graphite in hochcarbdnleierenden

non-plastic polymers The formation of an elastic, solid carbon skeleton in which the graphite acts as an elastic element as well as a catalyst in the formation of the carbon bond.

Dieeoe carbon skeleton, in contrast to the ceramic or chemical bond, is capable of self-shrinking Temperaturwochsel harmless for the product to intercept. At the same time, by the coherent Carbon skeleton created good thermal conduction conditions, resulting in increased heat dissipation from the steel

contacting zones and thus leads to a reduction of wear in these areas.

Further positive effects for the operating behavior of wear materials are due to the low wetting effect of steel

and infiltration-inhibiting effect of the carbon. Also erosionhememmend proves that by the

Carbon bonding by means of graphite and non-fusible polymers achieved dense, only a few pores of small size

containing structure of the products. The stabilization: the carbon bond is optionally followed by a.

porosity-reducing and chemical reactivity-reducing corrosion inhibitor such as high oxygen affinity metals and / or their compounds.

AusfOlirungsbelsplel · The invention will be explained in more detail below with reference to two Ausführungsbelspielen.

Various refractory base materials, preferably natural and / or synthetic sintered magnesia, fused magnesia, or magnesia-based recycle materials, as well as combinations of these materials, may be used to make unfired refractory squeeze closure slide gate materials. The proportion of refractory material, graphite and additives is determined by the specific conditions of use of the particular product.

example 1

This example relates to an unfired fireproof gagging material for slider closures based on natural sintered magnesia for use in predominantly erosive and thermal cycling applications. After the molding process, the molded bodies were subjected to a temperature treatment at 050 ° C. Composition:

natural Sinlermagnosia 90.0%

Graphite 3.0%

Phenol-formaldehyde resin liquid 3.5% solid 1.6%

Corrosion inhibitor 2.0%

Beltplel2

This example relates to an unfired refractory wear material for slide closures based on synthetic sintered magnesia for use with increased chemical stress.

The Formgebungeprozeß shooting verifiable elnoTempari ^ treatment at at 176 ⁰ C. Composition:

Synthetic sintered magnesia 82.0%

Graphite 12.0%

Phenolformaldehydhan; liquid 4.0%

test 1.0%

Corrosion inhibitor 1.0%

Claims (4)

1. Unburnt refractory wear material for gate closures of molten metal containing containers and aggregates, such as gate plates, Ausgesußkollektoren and other elements used in Schieberverschlußsystemen refractory Grundmaterialion, preferably natural or synthetic Sintermagnesia, fused magnesia, recycled material based on magnesia and combinations of these materials, characterized in that the refractory Components of the moldings are bound by a attributable to the use of non-molten polymers and graphite carbon bond and the carbon bond of the moldings at treatment temperatures up to 1000 ⁰ C is constructed. 2. Unburned refractory wear material for slide fasteners according to claim 1, characterized in that the treatment temperature of the moldings is at most 200 ⁰ C and the formation of the carbon bond takes place during the first heating to use temperature. 3. Unburnt refractory wear material for slide fasteners according to claim 1, characterized in that it is preferably phenoiformaldehyde and / or Furanharza in the non-meltable polymers and that a proportion of the resin component of the molding compound is added prior to molding in powder form. 4. Unburnt refractory wear material for gate valves according to claim 1, characterized in that the carbon bond is stabilized by a poronraumverringernden and the chemical reactivity reducing corrosion inhibitor.