| 摘要 |
PURPOSE:To obtain high P steel at a low cost by adding a substance contg. carbon to a converter from an upper part in the last stage of blowing and by forcing P2O5 in slag to be reduced to increase the amount of P in steel. CONSTITUTION:When the decarburization efficiency of oxygen begins to decrease at a point CB after vigorous decarburization during refining in a converter by the top blowing of pure oxygen, the amount of FeO in slag is rapidly increased, and the oxidation of P and Mn is caused again, decreasing the amounts of P and Mn in molten iron. At this time powdery or lump substance contg. carbon such as lump coke is added to the slag from an upper part. P and Mn oxides are reduced, and P having a weak affinity for oxygen returns to steel. |
