Device and method for casting large-sized compound steel ingot by using graphite electrode ring for preheating electroslag

Abstract

The invention provides a device and method for casting a large-sized compound steel ingot by using a graphite electrode ring for preheating electroslag. The device comprises a T-shaped electric conduction crystallizer, supporting arms and a lined electroslag furnace, wherein two transverse arms on a support are respectively used for lifting and dropping the graphite electrode ring and a self-consuming electrode ring; the lined electroslag furnace is used for slagging and pouring premelting slag into the T-shaped electric conduction crystallizer; and an annular bottom water tank is arranged onan ingot introducing plate. The method comprises the following steps of: (1) putting a core rod in the T-shaped electric conduction crystallizer, slagging the premelting slag in the lined electroslagfurnace, and forming a slag tank by pouring; (2) lowering the graphite electrode ring, and causing the graphite electrode ring, the slag tank, the upper crystallizer, a casting power source and the traverse arms to form an electric conduction loop, and heating the surface of the core rod and the slag tank by electrifying; and (3) when a preset temperature reaches, moving away the graphite electrode ring, inserting the self-consuming electrode ring into the slag tank, and carrying out electroslag casting. The method has high utilization rate of heat, can prevent interlayer slag from being generated on the compound interface of the steel ingot, facilitates the improvement of the quality of the steel ingot and simplifies the production equipment.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and casting, in particular to a device and method for preparing large-scale composite steel ingots by preheating electroslag melting and casting graphite electrode rings. Background technique [0002] At present, a prominent technological development trend of the equipment manufacturing industry is extreme manufacturing. On the one hand, it is developing towards ultra-micro and ultra-fine, and on the other hand, it is developing towards ultra-large. The development of large-scale and complex equipment in the fields of electric power, petrochemical, and metallurgy has put forward higher requirements for the large-scale casting and forging industry, and the demand for large-scale steel ingots is increasing. [0003] Among the million-kilowatt nuclear power units, whether it is the second-generation plus or the third-generation AP1000 and CAP1400, there are a large number of castings and forgings ...

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Problems solved by technology

[0006] In recent years, many researchers have been studying the effect of increasing the content of elements in the material on its performance. In the future, the elements that improve the performance of the alloy will continue to increase. For example, elements such as Cr, Mo, and W in the material can significantly improve its corrosion resistance. , therefore, high-alloy materials will definitely be the trend of future development; however, so far, the preparation of high-alloy steel ingots, especially the preparation of large-scale steel ingots, has not been well resolved; therefore, the preparation process and quality of large-scale steel ingots Research work related to control technology is very necessary

[0007] At present, the production methods of large steel ingots include casting method, multi-furnace continuous casting method, double crystallizer method, core electroslag casting method and electroslag melting casting method; Unavoidable problems such as segregation, porosity, and shrinkage cavity; and the process of electroslag casting composite method is mainly due to the problem of slag inclusion at the composite interface in the early stage of smelting. Due to the cold effect, the molten slag solidifies on the surface of the mandrel to form a slag shell. In the subsequent compound melting process, the thermal action of the slag pool and the molten metal pool on the surface of the mandrel cannot melt the slag shell quickly, but stays between the mandrel and the slag shell. between the working layers, resulting in slag inclusion at the composite interface, and quality defects in the lower part of the produced large composite ingot

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