| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for preventing the clogging of a ladle nozzle when an aluminum-killed steel is produced. <P>SOLUTION: In the case of producing the aluminum-killed steel with a continuous casting method, when the molten steel is treated with an RH-apparatus, a sample for analyzing the total oxygen concentration in the molten steel is sampled after adding Al for deoxidizing the molten steel, and the total oxygen concentration and the Al concentration contained in the molten steel, are analyzed during reflux flow thereof. Then, based on these values, the molten steel is adjusted so as to finish the reflux flow of the molten steel in the range of following formulae (1) and (2): in the case of being [Al]>0.03 mass%, 0.043×T.[O]+1.0≤t≤0.043×T.[O]+2.0 (1), and in the case of being [Al]≤0.03 mass%, 0.043×T.[O]+100×(0.03-[Al])+1.0≤t≤0.043×T.[O]+100×(0.03-[Al])+2.0 (2) äwherein [Al] is a sol. Al concentration (mass%) in the molten steel, provided that 0<[Al]<1.20; T.[O] is the total oxygen concentration (ppm); and t is the time from sampling for analyzing T.[O] to stopping of the molten steel reflux flow}. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
