A cored wire containing rare earth crystallizer pre-slag and its application

Abstract

The invention provides a cored wire containing rare earth crystallizer pre-melted slag and its application, wherein the cored wire includes a central layer, an intermediate layer and an outer layer from inside to outside, and the intermediate layer is composed of a rare earth alloy mixture. The middle layer is composed of pre-melted slag powder. In the present invention, rare earth and pre-melted slag are compounded to fully play the role of rare earth in metal smelting. At the same time, pre-melted slag is added to the core material to modify the reactants of rare earth in molten metal, preventing the rare earth reactants from affecting the slag system. The destruction of the pre-melted slag in the core material can reduce the manual addition of the pre-melted slag station, reduce labor intensity and reduce labor costs; compared with the surface contact reaction of ordinary pre-melted slag, the present invention directly adds the pre-melted slag through the wire feeding device Into molten metal, the reaction time is longer, the contact is more complete, and the effect of refining and impurity removal is better; the production process of the present invention is simple, easy to control, and does not require major adjustments to the existing process.

Description

technical field [0001] The invention belongs to the technical field of metal smelting, and in particular relates to a cored wire containing pre-melted slag of a rare earth crystallizer and an application thereof. Background technique [0002] At present, continuous casting technology has been highly valued by the metallurgical industry for its many advantages such as high efficiency, energy saving, high quality, easy automation and intelligence. The matching continuous casting mold powder has also been developed accordingly, and has become an indispensable metallurgical auxiliary material. The main functions of mold slag in continuous casting mold are: 1. Covering molten steel for thermal insulation; 2. Insulating air to prevent secondary oxidation of molten steel; 3. Absorbing non-metallic inclusions floating to the interface of steel slag; 4. Reducing the drawing resistance, Lubricate the billet and mold; 5. The liquid slag flowing into the gap between the billet shell an...

AI Technical Summary

Problems solved by technology

However, there are also a large number of problems to be solved in adding rare earth elements to the crystallizer

Rare earths are added into the crystallizer to react with oxygen and sulfur in molten steel to form non-metallic compounds with high melting points such as rare earth oxides, rare earth sulfides, and rare earth sulfur oxides. Generally, the melting point can reach about 2000°C. These compounds enter the mold powder and seriously deteriorate the protection. The performance of the mold slag will destroy the function of the mold slag, resulting in changes in the viscosity, melting point and alkalinity of the mold slag, which will easily cause the following production and quality accidents: 1. Cause the mold slag to crust and block the crystallizer; 2. Destroy the mold slag. The lubrication of continuous casting slabs causes steel leakage accidents; 3. The alkalinity of mold slag changes to corrode the nozzle, causing the nozzle to be lost and separated from the liquid surface, resulting in contact between molten steel and air, causing oxidation of molten steel

The reason for the above is that the speed and quantity of the supplementary addition of mold slag cannot match the speed and quantity of rare earth compounds produced by the reaction speed of rare earth and molten steel, and they all react with the floating rare earth compounds in the lower part of the slag, which cannot completely change the rare earth compounds. The nature of the compound, the rare earth compound with high melting point is still produced continuously with the addition of rare earth

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