Abstract: The production process of steelmarking bearing steel by 100 t converter is studied and analyzed with tlhermody namics. The co-operating control process of carbon preservation, dephosphorization, and temperature control (C-P-T) in converter steelmaking process is optimized and established and applied to produce bearing steel. The results show that the dephosphorization reaction in furnace does not stop immediately when the selective oxidation temperature of phosphorus and carbon comes but has a slow decay process. In order to meet the need of deep dephosphorization, the optimal time of first slagging out in early stage of the new process should be controlled between 350 s and 380 s, and the temperature range is 1 360-1 437 ℃. The decarburization rate model predicts that the decarburization rate of bearing steel in the late stage of smelting is (0. 21% -0. 28% )/min. In order to keep the requirement of carbon preservation and temperature control, the catch carbon and reblow can be adopted in the end phase of blowing to further accurately control the temperature of liquid steel. According to the production data statistics of a furnace service period, the heat ratio of end carbon, phosphorus and temperature hit the target at the same time accounts for 76.67% , and the purity of liquid steel is greatly improved.

Key words: Converter, GCr15 Bearing Steel, Thermodynamics, Carbon Preservation Dephosphorization Temperature Control, Co-operating Control , Purity

摘要： 对100 t转炉冶炼轴承钢生产过程进行了热力学研究与分析,优化建立了转炉冶炼过程保碳、脱磷、控温(“C-P-T”)的协同控制工艺路线,并应用于轴承钢冶炼生产。结果表明,炉内脱磷反应不会在磷碳选择性氧化温度到来时立刻停止,而是有一段缓慢的衰减过程。为了深脱磷的需要,冶炼前期一次倒渣的最佳时间应控制在350～380 s,温度区间为1 360～1 437℃;通过脱碳速率模型预测出轴承钢冶炼中后期的脱碳速率为(0.21%～0.28%)/min;为了保碳控温的需要,在吹炼末期可采取高拉碳补吹的方式进一步精确调控终点钢液温度。一个炉役期生产数据统计显示,终点碳、磷、温度三者同时命中目标的炉次占比达到了76.67%,钢液纯净度得到大幅提升。

关键词: 转炉, GCr15轴承钢, 热力学, 保碳脱磷控温, 协同控制, 纯净度