Method for rapidly replacing online tundish of ultra-wide thin slab continuous casting machine

Abstract

The invention discloses a method for quickly replacing an online tundish of an ultra-wide thin slab continuous casting machine, which comprises the following specific steps: before replacing the tundish, controlling the thickness of a covering slag layer in a crystallizer, cleaning sintered slag blocks in the covering slag layer, and cleaning up covering slag strips attached to the wall of the crystallizer; before the tundish is replaced and after the steel ladle is closed, along with continuous descending of molten steel in the old tundish, the pulling speed is controlled to descend, and secondary cooling water weak cooling control is carried out in the pulling speed control process; after the tundish is replaced, the pulling speed is controlled to be increased, and secondary cooling water is controlled to be normally cooled; the first preheating position new tundish and the pouring position old tundish are switched by starting the first tundish trolley and the second tundish trolley, meanwhile, the first tundish trolley is driven to the pouring position from the first preheating position, the method is suitable for a continuous casting machine, and rapid and safe replacement of the ultra-wide sheet billet tundish can be effectively achieved through the method.

Description

technical field [0001] The invention belongs to the technical field of continuous casting machines, in particular to a method for rapidly replacing an on-line tundish for an ultra-wide thin slab continuous casting machine. Background technique [0002] The function of the continuous casting machine mold is to force the continuously injected high-temperature molten steel into it through the water-cooled copper plate to forcibly cool it, and to export its heat, so that it rapidly solidifies into a slab with the required cross-sectional shape and shell thickness, and makes this The casting billet with the seed core still in liquid state is continuously pulled out from the lower mouth of the mold to create conditions for its complete solidification in the secondary cooling zone. Due to the limited service life of the tundish lining and other shaped refractory materials, the tundish needs to be replaced when the service life reaches the limit. In the past, the ultra-wide and thi...

AI Technical Summary

Problems solved by technology

In the past, ultra-wide thin slabs (thickness 150mm, maximum width 3250mm) were replaced with tundishes according to the mode of stopping pouring, pulling out the tail billet, lifting the dummy, and starting pouring, etc., which required 65 minutes of downtime, and the effective operation rate was limited to a certain extent.

[0003] In the quick-change tundish test before the ultra-wide thin slab, due to its large width and relatively thin thickness, the tail shell of the cast slab in the mold shrunk too much, resulting in a large air gap with the mold wall, resulting in re-casting The abnormal situation that the molten steel seeps out of the mold along the air gap in the end causes the foot roll of the mold to stick to the cold steel, and there is a big hidden danger in production

Furthermore, once a new tundish arrived at the pouring position, it could not be pulled out after pouring, and had to be pulled out manually to prepare for production again. The single impact time was up to 4 hours

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