JPS55126356A - Continuous casting method of steel - Google Patents

Abstract

PURPOSE: To continuously cast the steel which has internal quality good and even over the entire length of the slab by stopping an electromagnetic rabbling device and adding internal quality modifier to tundish or mold in the initial period of casting.

CONSTITUTION: The addition of the internal quality modifier is accomplished at the time of starting of casting. To obtain a tesseral crystal rate of, e.g., about 50% or more by installing an electromagnetic rabbling device under the mold, the addition is performed until at least about 50% of the unsolidified phase reaches the range where the action of electromagnetic rabbling reaches. On the other hand, when the electromagnetic rabbling device is built in the mold, the addition is performed until it becomes possible to sufficiently perform the cooling in the initial period of casting, there is no more fear for breakout and the electromagnetic rabbling can be applied. In both cases, the addition of the internal quality modifier is stopped after this and the electromagnetic rabbling is done. As the internal quality modifier, one or more kinds of nucleus forming agents, such as TiN, ZrN and rare earth metals, are used in the case of achieving the increase in tesseral crystal ratio and deoxidizers, such as Al, are used in the case of performing continuous casting of undeoxidized steel.

COPYRIGHT: (C)1980,JPO&Japio