Method for improving quality head slab of IF steel casting slab

Abstract

The invention discloses a method for improving quality of a head slab of an IF steel casting slab. The method includes: adding a covering agent when molten steel tonnage of a continuous casting tundish reaches 35 tons; putting start powder and crystallizer casting powder onto a crystallizer platform; controlling pulling rate after starting at 0.2m / min, increasing the pulling rate to 0.4m / min at increasing acceleration less than or equal to 0.05m / min2, and maintaining for 30s+ / -5s; increasing the pulling rate from 0.4m / min to 0.8m / min at increasing acceleration less than or equal to 0.05m / min2,and maintaining for 30s+ / -5s. Through a series of measures like reasonably controlling adding moment of the covering agent of the tundish, reasonably controlling start tonnage of the tundish, increasing floating time of inclusion, reasonably controlling adding moment of the start powder and the casting powder into a crystallizer and optimizing tensioning speed when starting casting, entrapped slag can be well controlled to be mingled within a range of 4m of the head, yield is increased, and loss caused by the fact that cutting length is too long is lowered.

Description

technical field [0001] The invention relates to the technical field of continuous casting, in particular to a method for improving the quality of an IF steel billet head billet. Background technique [0002] The head billet refers to the first cast billet of a certain pouring time in the continuous casting process. Since the liquid steel is in contact with the air and the covering agent in the tundish when the continuous casting is started, the molten steel is oxidized, and the oxygen content in the head billet rises. At the same time , when the continuous casting starts, the liquid level in the flow field of the crystallizer fluctuates greatly, which will easily cause the inclusion of mold slag, and the phenomenon of slag entrainment will occur, resulting in poor cleanliness of the first billet molten steel, and the quality cannot reach the quality of the normal billet. Therefore, only The head blank can be treated by downgrading or scrapping, resulting in material waste. ...

AI Technical Summary

Problems solved by technology

[0003] This application provides a method for improving the quality of the first billet of IF steel casting, which solves the problem that the cleanliness of the molten steel of the first billet in the prior art is poor, and the quality cannot reach the quality of the normal billet, so that the first billet can only be treated by downgrading or scrapping. , a technical problem that causes material waste

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