Kinetic Study on Decarburization of Molten Iron and Iron-Chromium Alloy in Ultra Low Carbon Concentration Range

1、将氩氧混合气吹到熔体表面进行脱碳。即使氧分压相当低，熔体表面也会形成氧化膜并降低脱碳速率。实验结果通过考虑氧化膜处速率过程的反应模型进行了解释。 2．在氧化镁、氧化铝、氧化钙坩埚中铁水吹氩脱碳实验中，熔体中的碳与坩埚氧化物反应生成CO。提出了考虑氧化物解离反应、坩埚氧化物界面处CO生成反应等的反应模型。该模型能够解释实验结果。 3．为了提高含有固体氧化物的铁水及铁铬合金的脱碳率，采用真空抽吸脱气方法在极低碳浓度范围内进行脱碳。反应界面处形成的CO气体通过多孔氧化物被吸入，多孔氧化物的另一侧保持真空。脱碳实验是通过将多孔管浸入熔体中进行的。将管内部抽真空。管材成分为Al_2O_3、SiO_2、MnO、Fe_2O_3、Cr_2O_3等。氧化物解离压越高、孔隙率越大，脱碳率越高。 Al_2O_3-SiO_<>管可以比Al_2O_3管更快地使熔体脱碳。此外，含有方石英(SiO_2)形式的SiO_2的管子的脱碳率高于含有莫来石(3Al_2O_3·2SiO_2)形式的SiO_2的管子。熔体倾向于渗入Al_2O_3-Fe_2O_3管的孔隙中。

1. An argon-oxygen mixture was blown onto the surface of molten iton for decarburization. Even though the oxygen partial pressure was quite low, an oxide film formed on the melt surface and reduced the rate of decarburization. The experimental result is explained by a reaction model in which the rate process at the oxide film is considered.2. In experiments of decarburization of molten iron in magnesia, alumina and calcia crucibles with blowing argon gas, carbon in the melt reacted with crucible oxides to form CO. A reaction model is proposed in which the dissociation reaction of the oxide, CO formation reaction at the crucibleoxide interface, etc. are taken into account. The model can explain the experimental results.3. In order to enhance the decarburization rate of molten iron and ironchromium alloy with solid oxides, the vacuum suction degassing method was adopted for decarburization in a very low carbon concentration range. The principle of the method'is that the CO gas formed at the reaction interface is sucked through the porous oxide, the other side of which is kept at a vacuum. The decarburization experiments were made by immersing a porous tube into the melt. The inside of the tube was evacuated. The components of the tube were Al_2O_3, SiO_2, MnO, Fe_2O_3, Cr_2O_3, etc. The decarburiza-tion rate was higher for the oxide of higher dissociation pressure and the tube of larger porosity. An Al_2O_3-SiO_<> tube could decarburize the melt much faster than an Al_2O_3 tube. Moreover, the decarburization rate was higher for the tube containing SiO_2 in the form of cristbalite (SiO_2) than in the form of mullite (3Al_2O_3・2SiO_2). The melt tended to penetrate into the pore of Al_2O_3-Fe_2O_3 tube.