A refining cover for continuous casting tundish and its preparation method

Abstract

The invention relates to a refining cover for a continuous casting tundish and a manufacturing method of the refining cover. The refining cover comprises an outer arc plate, an inner arc plate and a dipping cover. A circulation seam is reserved between the outer arc plate and the inner arc plate, and communicated with a gap between a tundish cover and a steel slag layer inside the tundish. Air exhaust holes penetrating through the dipping cover are formed in the dipping cover, through holes opposite to the air exhaust holes are formed in the inner arc plate, the air exhaust holes are communicated with the circulation seam through the through holes, argon is blown in through air curtain ventilation bricks, an air curtain barrier with the large continuous intensity is formed between the air curtain ventilation bricks and the dipping cover, the inclusions are captured and are adsorbed and removed by the steel slag layer, the argon breaks through the steel slag layer below the dipping cover to move upwards continuously and enters the circulation seam through the air exhaust holes and the through holes, the argon enters the position above the steel slag layer of the tundish through the circulation seam, and argon seal is formed in the space between the steel slag layer inside the tundish and the tundish cover. The steel slag face is protected, secondary oxidation of liquid steel is avoided, the 0.5 level of the four kinds of inclusions in LHG2 steel reaches more than 90%, and the cleanliness of the liquid steel is greatly improved.

Description

technical field [0001] The invention relates to a refining cover for a continuous casting tundish and a preparation method thereof, belonging to the technical field of iron and steel metallurgy continuous casting tundish technology. Background technique [0002] The continuous casting tundish air curtain retaining wall technology is a new technology developed at the end of the 20th century to remove non-metallic inclusions in the molten steel in the continuous casting tundish. Bricks are placed at a certain position at the bottom of the tundish, and argon gas is blown in, and the argon gas floats through the breathable brick to form a micro-bubble air curtain barrier. The purpose of removing inclusions and purifying molten steel. [0003] Although the existing air brick air curtain retaining wall can remove the inclusions in the molten steel to a certain extent and serve the purpose of purifying the molten steel, it still has the following technical defects. Large blowing ...

AI Technical Summary

Problems solved by technology

However, this invention has the following disadvantages: 1) The cover body (12) of the dipping hood is a single-layer steel plate structure, which is prone to deformation under high temperature conditions and causes the refractory material of the immersed part (13) to fall off, resulting in a low service life of the dipping hood

2) There is an exhaust hole on the cover body of the dipping hood, and the argon blown out from the air-permeable brick air chamber passes through the molten steel gas and is discharged from the exhaust hole on the dipping hood, and the hot and humid argon directly flushes the tundish above the dipping hood The cover is lined with refractory material (not shown in the figure), and the airflow washes the same position of the tundish cover lined with refractory material for a long time, causing the liner to delaminate and contaminate the molten steel. Over time, the tundish cover will become tortoise Cracks and deformations seriously affect the service life of the tundish cover, resulting in increased costs; 3) The argon gas blown from the gas chamber of the breathable brick permeates through the molten steel and is directly discharged out of the tundish through the vent hole on the immersion cover. Circulation utilization, resulting in waste of argon resources

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