STEEL CONTINUOUS CASTING METHOD

• Main Authors: SASAKI TOMOYUKI, TSUKAGUCHI YUICHI
• Format: Patent
• Language: English; Japanese
• Published: 05.08.2021
• Subjects: CASTING; CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES; PERFORMING OPERATIONS; POWDER METALLURGY; TRANSPORTING

To provide a steel continuous casting method that is able to suppress clogging of an immersion nozzle.SOLUTION: A predetermined zirconia graphite-based refractory is arranged on all or a part of an internal surface of an immersion nozzle for continuous casting. One electrode is connected to the immersion nozzle, and the other electrode is immersed in molten steel in a tundish to constitute an energizing circuit. Energization is carried out so that the absolute value of an average current density in the immersion nozzle becomes a 1 - 90 mA/cm2 and with an alternating pulse current-waveform in which a polarity is alternately switched between positive and negative. A period of the alternating pulse waveform is a 0.5 ms - 20 ms. The average current density×an energization time when the polarity of the immersion nozzle is positive, is greater than the average current density×an energization time when the polarity of the immersion nozzle is negative. Thereby, casting is performed while the polarity of the average current density of the immersion nozzle is positive.SELECTED DRAWING: Figure 1 【課題】浸漬ノズルの閉塞を抑制することができる鋼の連続鋳造方法を提供する。【解決手段】連続鋳造用の浸漬ノズルの内面の全体あるいは一部に所定のジルコニアグラファイト系の耐火物を配置し、浸漬ノズルに一方の電極を接続するとともに、タンディッシュ内の溶鋼に他方の電極を浸漬して通電回路を構成し、浸漬ノズルにおける平均電流密度の絶対値が１〜９０ｍＡ／ｃｍ２となり、極性が正負交互に入れ替わる交流パルス状の電流波形で通電し、その交流パルス状波形の周期が０．５ｍｓ〜２０ｍｓであり、浸漬ノズルの極性が負の場合の平均電流密度×通電時間よりも、浸漬ノズルの極性が正の場合の平均電流密度×通電時間の方が大きいことによって、浸漬ノズルの平均電流密度の極性が正となるように通電しながら、鋳造することを特徴とする。【選択図】図１