Hundred-ton large-scale three-phase electroslag furnace feeding technique

Abstract

The invention relates to a hundred-ton large-scale three-phase electroslag furnace feeding technique. In the feeding process, a feeding electrode of which the diameter is 65-75% of the normal remelting electrode is adopted, and the electrode center circle and input power are adjusted to gradually reduce the depth and diameter of the bath, thereby implementing favorable feeding of hundred-ton steel ingots. In the feeding process, the effective input power is 40-55% of normal remelting, the melting speed is controlled at 0.3-0.8 t / h, and the buried depth is controlled at 10-20mm; in the early feeding stage, the diameter of the electrode center circle is one half of the crystallizer; and in the later feeding stage, the diameter of the electrode center circle is adjusted to 25-30% of the crystallizer. The feeding technique provided by the invention can control the shrinkage cavity depth of the hundred-ton electroslag ingot with the diameter of 1800mm at 100-240mm or so, whereas the shrinkage cavity depth of the existing feeding technique is 600mm or so, thereby enhancing the utilization ratio of the steel ingot.

Description

technical field [0001] The invention relates to a feeding process in the remelting and smelting process of a large-scale three-phase electroslag furnace (hundred tons). Background technique [0002] The diameter of the hundred-ton electroslag ingot exceeds 1800mm. If the feeding is not good, it is easy to cause shrinkage at the top, which will affect the utilization rate of the steel ingot. [0003] There are generally two ways of electroslag remelting feeding: continuous feeding and intermittent feeding. The main method of continuous feeding is to reduce the current, reduce the depth of the molten pool, and relatively increase the solidification speed. Since the liquid metal is continuously filled, the purpose of feeding is achieved. The main method of intermittent feeding is to implement at the end of smelting: power failure→interval for a period of time→power on→re-power outage→interval for a certain period of time→re-power→re-power outage. Smaller, for large cross-sect...

AI Technical Summary

Problems solved by technology

[0004] In the electroslag smelting of a hundred-ton three-phase electroslag furnace, if the above two methods are used for feeding, the former will cause the slag temperature to drop suddenly due to the excessive reduction of current, and the electrode rod will not melt at all or the melting amount cannot guarantee the proper molten steel Supplementation will easily lead to shrinkage cavity, porosity and other phenomena, and the material utilization rate will decrease; if intermittent feeding is adopted, it will lead to continuous power failure and power transmission during the production process, the fluctuation of the slag pool is relatively large, the temperature field is unstable, and the slag skin is easy to Cracking, resulting in poor surface quality of electroslag ingots, and internal inclusions are not easy to control

[0005] Using the existing feeding process, the shrinkage cavity depth of a 100-ton electroslag ingot with a diameter of 1800mm is generally about 600mm, and the yield and utilization rate of the steel ingot are low