高钛铁水转炉脱钛研究

Study on Titanium Removal from High-Titanium Molten Iron in Converter

钛在轴承钢中易形成硬度高、棱角状的碳氮化物,对轴承钢的疲劳寿命极为不利,因此,需要严格控制轴承钢中钛含量。对高钛铁水的转炉脱钛过程进行了研究,提出了双渣法脱钛:第一阶段低温脱钛保碳,第二阶段换渣高温冶炼。脱钛保碳结束后进行换渣操作,倒渣温度控制在1 410~1 440℃,此时钢液中碳质量分数为3%~4%,钛含量控制在20~30μg/g。建议出钢温度控制在1 640~1 670℃,碳质量分数达到0.5%~0.7%,转炉出钢钛含量可从原铁水中的300μg/g降低至5~15μg/g。

Titanium is easy to form angular carbonitrides of high hardness in bearing steel, which is extremely detrimental to the fatigue life of bearing steel. Therefore, it is necessary to strictly control the titanium content in bearing steel. The removal of titanium from high-titanium molten iron in converter was studied, and a double slag method for removal of titanium was proposed: the first stage of low-temperature removal of titanium and carbon conservation, and the second stage of slag replacement and high-temperature smelting. The slag replacement operation was carried out at the end of titanium removal and carbon conservation, and the slag dumping temperature was controlled at 1 410 to 1 440 ℃. At this moment, the mass fraction of carbon in molten steel was 3% to 4%, and the titanium content was controlled in the range of 20 to 30 μg/g. It was recommended that the tapping temperature is controlled in the range of 1 640 to 1 670 ℃, the mass fraction of carbon reaches 0.5% to 0.7%, and the titanium content of converter tapping is reduced from 300 μg/g in the raw molten iron to 5-15 μg/g.