Method for replacing tundish of crystallizer at high liquid level

Abstract

The invention provides a method for replacing tundish of a crystallizer at high liquid level, belonging to the field of steel-making. Before the tundish is replaced in a continuous casting way, the molten steel in the crystallizer is lifted up to the position of 50mm at the upper edge of a crystallizer copper plate; when the pouring is started, the initial pulling speed is 0.4m / min; within 1.5 minutes after starting, the slag skin is removed and the liquid surface is stabilized; subsequently the pulling speed is promoted to 0.1m / min at the increment of 0.1m / min per 20 seconds; within 30 seconds, the thickness of the adjusting and protecting slag is measured; subsequently the pulling speed is promoted to 1.0m / min at the increment of 0.1m / min per 25 seconds and the liquid level of the crystallizer is stabilized; after the liquid level of the crystallizer is stabilized for 1 minutes, an automatic liquid level control device is arranged in the liquid; after the automatic liquid level control device is arranged in the liquid for 1 minutes, the dipping type water gap insertion depth is adjusted to comply with the technological requirement; after the liquid level is stabilized for 2 minutes, the pulling speed is promoted; the promotion amplitude is 0.05m / min and the liquid level is stabilized for 1.5 minutes when the pulling speed is promoted by 0.05m / min; subsequently whether the tundish temperature complies with the steel type specification is determined; and the pulling speed is promoted to the target pulling speed. The method has the advantages of effectively avoiding the steel suspension accident of the crystallizer owning to the splashing of the molten steel.

Description

technical field [0001] The invention belongs to the field of steelmaking, and in particular relates to a method for replacing a tundish at a high liquid level of a crystallizer. Background technique [0002] In the continuous casting production process, in order to improve production efficiency and realize multi-furnace continuous casting, the method of quickly changing the tundish is generally adopted at present, and the low liquid level changing process is used. Lower it to 150mm from the edge of the copper plate, and use a baffle to prevent the molten steel from splashing during the pouring process, as shown in Figure 1. Using this operation method not only has a large amount of traces on the slab, but also is prone to accidents such as hanging steel in the crystallizer and pulling off steel at the traces during the pouring process. Contents of the invention [0003] The invention provides a method for replacing a tundish at a high liquid level of a crystallizer. The t...

AI Technical Summary

Problems solved by technology

Using this method of operation not only has a large amount of traces on the slab, but also is prone to accidents such as crystallizer hang-ups, pull-offs at the joints, and other accidents during the casting process.