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根据混合控制(包括真空室钢液中碳、氧的质量传递和碳、氧的循环流传递)机理,为阐明氧浓度对脱碳速度的影响,开发了一种用于 RH 脱碳新的反应模型。此模型还能够预测用 KTB 法把氧吹到真空室钢液面上对脱碳速度的影响。在 RH 的若干试验中发现,当钢包中钢水的碳浓度 C_L>200ppm 时,脱碳速度对钢包内钢水的氧浓度 O_L 有很大的依赖关系,而当钢水的碳浓度 C_L<200ppm 时,脱碳速度与钢水的碳浓度明显地成正比,因此,它对氧浓度 O_L 的依赖性就很小。虽然,模型研究预测的脱碳速度对 O_L有依赖关系,但是,计算的脱碳速度和观测的速度之间仍有些差别。这种差别可能由一部分尚未确知通过何种途径进入真空室内钢液中的氧所引起的。这部分氧既可能是由于熔渣被吸入到真空室带来的,亦可能是大气中空气渗进的结果。还用最新的数据研究了(在<50ppm 超低碳范围内)RH 真空室内碳的传质容积系数 ak_c,研究表明,ak_c 对碳浓度 C_L 和循环流量 Q 有很大的依赖性。
According to the mechanism of mixed control (including the mass transfer of carbon and oxygen in the molten steel of the vacuum chamber and the circulation of carbon and oxygen), to elucidate the effect of oxygen concentration on the decarburization rate, a new reaction for RH decarburization model. The model also predicts the effect of KTB on the rate of decarburization by blowing oxygen to the molten steel level in the vacuum chamber. In a number of RH tests, it was found that the rate of decarburization depends strongly on the oxygen concentration O_L of the molten steel in the ladle when the C_L concentration of the molten steel in the ladle is 200ppm. However, when the carbon concentration C_L <200ppm, The rate of decarburization is clearly proportional to the carbon concentration of the molten steel, so its dependence on oxygen concentration O_L is small. Although the decarburization rates predicted by the model studies are dependent on O_L, there are still some differences between the calculated rates of decarburization and observations. This difference may be caused by the fact that some of the ways in which the oxygen in the molten steel in the vacuum chamber has not been ascertained have been determined. This part of the oxygen may be due to the slag being drawn into the vacuum chamber, or it may be the result of air infiltration into the atmosphere. The mass transfer coefficient, ak_c, of carbon in the RH vacuum chamber (<50ppm in the ultra-low carbon range) was also updated with the latest data. Studies have shown that ak_c has a large dependence on the carbon concentration C_L and the recycle flow rate Q.