Flat blank continuous casting closed-top technology for preventing steel liquid roof-falling

Abstract

A slab continuous casting capping process for preventing molten steel from badly bleeding relates to a continuous casting field for smelting, comprises: section decelerating, adding with aluminum bar and raising speed of tailing slab. The section decelerating after bale pouring is to prevent decelerating too fast in final period and too large of the forward-shift in cogging region, thus it has no time to form the slab shell. Agitating oxygen pipe and water drilling for cooling are to ensure the empty slab shell have enough length so that the molten steel moving upwards has enough space. In order to continue desoxy a wild molten steel and prevent rising caused by tail part ebullition, 1-2 kilogram aluminum bar is inserted into open steel. During the final period, drawing tailing slab is carried out by raising speed to a speed higher than that of 0.2-0.3m / min during generally drawing strips, when the speed is too low, defects such as crack,etc., may appear, while the speed is too high, badly bleeding of the molten steel may occurs. The advantages of the invention are in that industrial accident of badly bleeding of the molten steel in the final period of the slab continuous casting process so that incidence rate of the molten steel badly bleeding can be reduced from 5 times / month to 0 time / month, meanwhile, incidence rate of tailing slab transverse crack during pouring peritectic steel and alloy steel can be reduced to 50% or more.

Description

technical field [0001] The invention relates to the technical field of smelting and continuous casting, in particular to a casting process for a straight arc continuous casting machine which applies a dynamic soft reduction technology and a dynamic secondary cooling technology to continuous casting slabs. Background technique [0002] Anyone engaged in smelting technology knows very well that the slab capping process is an important part of the continuous casting process, which is the process of treating the molten steel in the crystallizer at the end of continuous casting. Before the present invention was proposed, the main operation process of the existing technology was as follows: when the last furnace molten steel ladle was poured and the weight of the tundish molten steel dropped to about 4 tons, the continuous casting machine operator directly reduced the casting speed to 0.3- 0.4m / min, inform the control room personnel to change the water dis...

AI Technical Summary

Problems solved by technology

It is mainly manifested in the following two aspects: 1) The deceleration range is too large, and the dynamic light reduction area moves to the front end during deceleration. In order to ensure the surface temperature of the billet, the dynamic secondary cooling model cannot increase greatly in a short time. The amount of cooling water, and the tail adopts the method of heat preservation and capping, resulting in the high temperature of the billet at the tail, the empty shell is not long enough, and there is not enough space for the molten steel moving to the front, so the situation of roof fall often occurs

Damage the main equipment of the casting machine, affect the working time, reduce the productivity and increase the production cost

2) Low casting speed takes a long time, the surface temperature of the billet at the tail is low, and the incidence of transverse cracks under the skin of the billet reaches more than 10% when casting peritectic steel and alloy steel, which reduces the yield of the product

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