Double-layer tundish covering agent

Abstract

The invention relates to a double-layer tundish covering agent, which consists of an upper-layer covering agent and a lower-layer covering agent. The upper-layer covering agent is not contacted with molten steel; the lower-layer covering agent is directly contacted with the molten steel; and the proportion of the upper-layer covering agent is between 15 and 45 percent, and the proportion of the lower-layer covering agent is between 55 and 85 percent. The upper-layer covering agent comprises the following components in percentage by mass: 1 to 5 percent of CaO, 1 to 8 percent of MgO, 88 to 92 percent of SiO2, 1 to 5 percent of Al2O3, 1 to 5 percent of C and the balance of inevitable impurities; and the lower-layer covering agent comprises the following components in percentage by mass: 56 to 63 percent of CaO, 3 to 11 percent of MgO, 1 to 8 percent of SiO2, 23 to 28 percent of Al2O3, 0.01 to 0.8 percent of C and the balance of inevitable impurities. The double-layer tundish covering agent has good heat-insulating property, high capability of absorbing Al2O3 nonmetallic inclusion, weak oxidbillity and low carburetion amount of the molten steel, and can be used for the continuous casting production of interstitial-free steel.

Description

technical field [0001] The invention belongs to the technical field of continuous casting, and in particular provides a double-layer tundish covering agent. Background technique [0002] In the continuous casting process, the tundish is a transition vessel between the ladle and the mold. Its technological purpose is to stabilize the steel flow, reduce the static pressure of the molten steel, and reduce the impact of the steel flow on the liquid level of the mold; Each crystallizer of the casting machine; store an appropriate amount of molten steel to realize continuous casting of multiple furnaces, etc. [0003] With the continuous improvement of steel purity requirements, people no longer regard the tundish as a simple refractory transition vessel between the ladle and the crystallizer, but use it as a refining vessel and continuously develop its metallurgical functions. Among them, adding a covering agent on the molten steel surface of the tundish is the simplest and most...

AI Technical Summary

Problems solved by technology

[0011] In order to achieve the above purpose and solve the problem of acidic covering agent absorbing Al 2 o 3 The ability of non-metallic inclusions is low, the oxidation is high, and the thermal insulation performance of alkaline covering agents is poor. Generally, acidic covering agents and alkaline covering agents are very easy to increase the carbon content of molten steel. Reasonable matching of components provides a double-layer tundish covering agent for interstitial atom-free steel