Method for preventing shrinkage of blank shell of quick-replacement tundish of continuous casting machine

Abstract

The invention discloses a method preventing shrinkage of a blank shell of a quick-replacemnet tundish of a continuous casting machine. The method includes the following steps of reducing the pulling speed in advance, fishing protective slag in a crystallizer, and avoiding pause of the pulling speed when a connecting piece is added. By means of the method for replacing the tundish in the design, the superheat degree of last-furnace molten steel in the tundish is above 25 DEG C, when the superheat degree is lower than 20 DEG C, the shortcoming that shrinkage of the blank shell is only preventedby a supporting piece is overcome, shrinkage of the blank shell is effectively prevented, and smooth pouring of replacement of the tundish is ensured; enough protective slag is added into two narrow sides in the crystallizer, the heat loss of two-dimensional heat transfer of the narrow sides of the crystallizer is effectively reduced, coincidence of heat of the narrow and wide sides is ensured, and thermodynamic conditions are provided for preventing shrinkage of the blank shell; and by means of the method, shrinkage of the blank shell of the quick-replacement tundish is controlled and prevented, different superheating degrees need to be considered, simplicity and maneuverability are achieved, and convenience is especially achieved on the crystallizer requiring manual adjustment of a waterflow valve.

Description

technical field [0001] The invention relates to the technical field of continuous casting machines, in particular to a method for quickly changing a tundish of a continuous casting machine to prevent the shell from shrinking. Background technique [0002] The quick change of tundish for continuous casting machine is one of the important ways to improve the production rate of steelmaking plants. , the billet shell has different degrees of shrinkage, and the new tundish is extremely prone to the failure of the new submerged nozzle to be inserted into the billet shell during the pouring level drop process, resulting in failure of pouring and production accidents affecting the production rhythm. When the continuous casting machine is changing the tundish quickly, since there is no molten steel injected into the mold temporarily, it takes at least 3 minutes from the time when the old tundish is removed from the pouring position to when the new tundish is opened to the pouring pos...

AI Technical Summary

Problems solved by technology

In order to ensure the success of the quick change of the tundish, it is necessary to prevent the shrinkage of the billet shell. The current technology for preventing the shrinkage of the billet shell is to control the low casting speed time, reduce the water flow rate of the crystallizer, and only add supports, etc. There are complex operations or When the degree of superheat is low, it is still unable to effectively prevent the shell from shrinking

In the existing quick-change tundish process, since it takes a certain amount of time from the opening of the old tundish to the opening of the new tundish to the pouring position, it takes a longer time in case of an abnormal situation, or the last furnace of molten steel in the old tundish is over When the heat is low, the billet shell in the crystallizer will shrink. When the new tundish is poured, it is difficult to insert the submerged nozzle into the billet shell for pouring, resulting in the failure of the quick change tundish

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