Cleaning method for longitudinal cracks on the surface of continuous casting slab based on thermite self-propagating technology

Abstract

The invention discloses a continuous casting plate blank surface vertical crack cleaning method based on an aluminum heat self-propagating technology. The method comprises the following steps: (1) material preparation: components of a thermite comprises Al, Fe2O3, Fe, Mn, Si and other alloys with the grain diameter of 100 microns, and the components are uniformly mixed; (2) feeding: the amount of the thermite for fully filling cracks is calculated by the widest, deepest and longest sizes of the cracks; the actual feeding amount is 1.2-1.5 times as much as that of the calculation amount; the feeding range covers the whole vertical crack length and extends towards the two ends for 5cm-20cm respectively; the end part region of a material belt is gradually narrowed; (3) ignition reaction: after the feeding is finished, the ignition reaction is carried out on the thermite by taking ignited fuel gas spraying gun flame to get close to the end part of the thermite material belt on the surface of the casting blank, so that a continuous casting plate blank surface vertical crack can be cleaned. The continuous casting plate blank surface vertical crack cleaning method can effectively optimize plate blank vertical crack treatment effect; the treatment efficiency stability and the blank yield are improved; the secondary defect generation rate and the fuel consumption are reduced; the environment load and the labor intensity of operators are alleviated, and the accident occurrence rate is reduced.

Description

technical field [0001] The invention belongs to the technical field of continuous casting and steel casting, and in particular relates to a method for cleaning longitudinal cracks on the surface of continuous casting slabs based on the aluminothermic self-propagating technology. Background technique [0002] Longitudinal cracks are one of the most common surface defects of continuous casting slabs, which have an important impact on the quality and yield of continuous casting slabs and the quality of subsequent rolling products. Relevant studies have shown that longitudinal cracks on the surface of the slab occur in the mold and further deteriorate during the secondary cooling process of the slab, and as the width of the slab increases, the uneven stress distribution becomes more obvious, and the temperature gradient caused by cooling increases. The higher the incidence of final longitudinal cracks, the larger the size and depth of cracks, and the more serious the impact. Si...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide a continuous casting slab surface longitudinal crack cleaning method based on the aluminothermic self-propagating technology, so as to overcome that the existing casting slab surface crack flame cleaning method is not enough to ensure that the molten metal melts effectively Penetration only covers the existence of cracks on the surface, which is likely to bring major safety hazards and quality hazards, and the operating environment is harsh, and when the width and depth of the longitudinal cracks are large, it is easy to produce more serious oxidation phenomena, resulting in slab yields Defects that may cause subsequent quality problems after severe drops and metal oxides embedded in cracks

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