INFLUENCE OF ALUMINUM HEATING ON THE MELT CLEANLINESS IN RH-OB PROCESS

摘要

The characteristics of the oxygen blowing treatment in RH operation at Pohang Works were investigated and the influence of oxygen blowing on the melt cleanliness was analyzed on the samples in field test. The examination on composition, size and shape of inclusions during RH-OB operation has been made for Al killed and Al & Si killed steel. The results show that during the oxygen blowing treatment melt cleanliness was deteriorated, however a sufficient circulation of the melt after the OB treatment improved the melt cleanliness to a similar level of the heats without OB treatment. The addition of CaO based flux is effective to improve the cleanliness in the melt with OB treatment. The influence of OB treatment in RH-OB operation was investigated on the cold rolled sheet products