DE2849897A1 - SPOUT FOR CONTINUOUS METAL CASTING - Google Patents

Description

Spout for the continuous casting of metals

The invention relates to a nozzle for the continuous casting of metals and especially of steel.

It is known that in the continuous casting of metals, in particular of Steel, the metal usually processed in a converter into a so-called The intermediate container is poured off from which it is continuously discharged via a special outlet pipe, the spout is named, flows into the mold; during the entire casting period The lower end of this spout generally dips into that in the mold Metal one.

The sink mostly consists of a combination of refractories Materials and mainly made of corundum, alumina silicate and graphite as well as in a smaller proportion of clay, silicon and silicon carbide, with also still other refractory components may be present in small quantities. One such a composition is hereinafter referred to as "conventional composition and is presented in the form of granules.

Such a spout not only has to be affected by the temperature of the cast metal can withstand thermal stresses, but also any kind of chemical attack by the metal, mechanical stresses as a result of the mold oscillating movements and finally the chemical attacks by the slag that goes through the process of melting the commonly used on the Covering powder applied to the surface of the liquid metal located in the mold are conditional.

These powders, the chemical reactions of which are sometimes exothermic, consist mainly of silica, alumina, CaO, MgO, alkaline substances, Carbon etc.

It was found that the coexistence of this Powder and liquid metal in contact with the sink is often a quick chemical Attack took place on the same, which in most cases extended to destruction of the attacked spout continued.

A wide variety of attempts have been made to the Reduce the impact of such attacks, however, can reduce the results achieved so far cannot yet be considered satisfactory.

The invention relates to a spout, the composition of which at least in the zone of combined contact with the encapsulated metal and the covering powder clearly better the attack through the oxides or silicates of the powder able to withstand.

The spout according to the invention is essentially characterized in that that its granules of conventional composition instead of its full or partial graphite content one or more refractory oxides (e.g. Zr, Al) and contains one or more refractory metals (e.g. Mo, Cr), where Oxides) and metal (s) at the stage of their preparation, preferably as a mixture present with a fine particle size distribution.

At the moment of making the sink, these two materials can be used either in the entire mixture consisting of different ingredients, or only be present in that zone of the same which is later in contact with reaches the liquid bath.

With regard to the desired final composition of the spout there are various options that can be regarded as useful.

According to a first embodiment, the solid oxide is located directly in granules of conventional composition instead of all or part Graphite, while the refractory metal is added later to the granulate produced in this way is added. As already mentioned elsewhere, there is the refractory oxide expediently, for example, from ZIXO2 or AL203 in fine distribution.

a second embodiment provides refractory oxide and refractory metal to combine beforehand in a cermet, which is then ground to granulate before addition will. In the latter pill it cannot be ruled out that the granules also a or several refractory metals or one or more refractory oxides added separately will.

It was found that spouts where the above Replacement was made, significantly better the various mechanical, thermal and chemical stresses caused by the encapsulated metal or

the covering powder can withstand.

J PATENT CLAIMS J,

Claims (7)

PATENT CLAIMS: 1. Spout for the continuous casting of metals, in particular of steel, characterized in that in the granulate forming for the spout used the otherwise known composition of the graphite content in whole or in part one or more refractory oxides and one or more refractory metals are replaced. 2. Spout according to claim 1, characterized in that the refractory oxide added directly to the granulate instead of all or part of the graphite content is, while the refractory metal is added later to the granulate produced in this way is. 3. Spout according to claim 2, characterized in that the refractory oxide made of ZrO2 or A1203 exists. Lf. Spout according to claim 1, characterized in that refractory oxide and refractory metal are combined to form a cermet, which is then added to the granulate has been crushed. 5. Spout according to claim 4, characterized in that the granules In addition to cermet, one or more refractory oxides are also added. 6. Spout according to claims 4 or 5, characterized in that In addition to cermet, one or more refractory metals are also added to the granulate are. 7. Spout according to claims 1 to 6, characterized in that the refractory oxides and refractory metals are added in a fine grain size distribution.