| 摘要 |
PROBLEM TO BE SOLVED: To enable medium and high carbon steel to be surely produced even when fluorite is not used.SOLUTION: A basicity of slag upon starting of blowing is set to be 0.8-1.2 and an oxygen feed speed is set to be ≤1.8 Nm/min/t, the oxygen feed speed is changed to 2.2 Nm/min/t-3.2 Nm/min/t while an oxygen quantity during the blowing is 3-10% of the total oxygen quantity of the total blowing after starting the blowing, Cao source is charged twice or more while the oxygen quantity during the blowing is 40-70% of the total oxygen quantity, a charging quantity of the Cao source per one time is set to be ≤16 kg/t, the oxygen feed speed during charging period of the Cao source is set to be ≤2 Nm/min/t, an interval of charging the Cao source is set to be ≥1 min, and the basicity of the slag when the blowing is finished is set to be 2.5-4. |
