Device and method for preparing large steel ingots by electroslag remelting with conductive crystallizer

Abstract

A device and method for preparing large steel ingots by electroslag remelting in a conductive crystallizer, including a power supply, an upper crystallizer, a lower mold, and a dummy plate; the upper crystallizer has an insulating section, an upper conductive section, and a lower conductive section; the upper conductive section, the lower conductive section, the consumable electrode and the dummy plate are respectively connected to the power supply; the method is: (1) assemble the consumable electrode; fill and seal the dummy plate and the lower edge of the lower crystallizer; (2) pour the slag into The upper crystallizer; (3) stop pouring slag, switch on and off to form different power supply circuits, and Joule heat will heat and melt the consumable electrodes; (4) start the ingot pumping system when the metal molten pool is in; (5) control the metal melting pool and monitor the liquid level through the liquid level detector; (6) When the solidified body reaches the target length, stop drawing the ingot and disconnect the power supply circuit. The method of the invention rationally optimizes the temperature field by changing the position and quantity of the conductive section and then changing the current path, thereby providing a guarantee for reducing element segregation and improving the surface quality of the ingot.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a device and a method for preparing large steel ingots by the electroslag remelting method of a conductive crystallizer. Background technique [0002] In recent years, the quality of major equipment forgings and steel ingots for special steel has received widespread attention. Large steel ingots such as rolls, as the main consumption equipment in steel rolling production, have become more demanding in use; the performance of rolls directly affects the quality of rolling mills. The production efficiency, the surface quality of the rolled material and the rolling cost. Therefore, how to manufacture steel ingots with suitable size, solidification structure and mechanical strength has become a common concern of the metallurgical industry. [0003] The traditional method of manufacturing large steel ingots generally has shortcomings such as serious solidification struc...

AI Technical Summary

Problems solved by technology

[0003] The traditional method of manufacturing large steel ingots generally has shortcomings such as serious solidification structure segregation, complicated manufacturing methods, and difficulty in forming; the electroslag remelting of conductive crystallizers is used to prepare large steel ingots, and the melting speed of electrodes is reduced by changing the ratio of different circuit currents , thereby reducing ingot segregation without deteriorating the surface quality of the ingot

[0004] However, there are also obvious shortcomings when using a conductive crystallizer to prepare steel ingots. Under the strong cooling effect of the crystallizer, the slag pool near the lower end of the conductive section is basically solidified due to the Joule heating effect formed by no current flowing through it. state, so the current mainly flows from the consumable electrode to the middle and upper part of the conductive section

Therefore, the high temperature zone of the slag pool is mainly concentrated in the upper part of the slag pool, and the position of the high temperature zone is too high, resulting in insufficient temperature at the bottom of the liquid slag pool, shallow metal molten pool, rapid solidification of molten steel, and insufficient heat to make the surface of the ingot The slag crust melted, resulting in too thick slag crust on the surface of the ingot cladding layer and poor surface quality

[0005] In summary, the electroslag remelting method of the conductive crystallizer circuit has the disadvantage of poor surface quality in the process of preparing steel ingots, which is not conducive to the preparation of large-size steel ingots with excellent performance in both surface quality and internal quality

Images