| 摘要 |
PURPOSE: A method for high pure steel is prepared which has little non-metallic inclusion by raising temperature of melted ore utilizing heat riser. CONSTITUTION: The steel composition comprises less than 0.07 wt.% of carbon, less than 0.05 wt.% of silica, 0.10-0.40 wt.% of manganese, less than 0.03 wt.% of phosphor, less than 0.03 weight 5 of sulfur, 0.01-0.10 wt.% of soluble aluminum, less than 0.010 wt.% of nitrogen, remainder of Fe and impurities. The composition is steel-tapped with 400-500 ppm of dissolved oxygen at 1,640- 1,650°C and downstream bubbled. The melted steel is heated up to casting temperature and upstream bubbled to 0.3-0.7 cubic meter/minute for more than 5 minutes to give the steel.
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