What are the three stages of furnace steel conversion? What is the law of the decarbonization reaction in each stage?
key word：Furnace steel blowing, steelmaking decarburization
Generally speaking, the conversion of a furnace of steel can be divided into three stages: the initial stage, the middle stage and the final stage according to the characteristics of the decarburization of the molten pool. The decarburization rate of the first stage increases almost linearly with the blowing time. Although the carbon content in the metal is very high at this time, it is beneficial to the oxidation reaction of carbon. However, due to the lower temperature of the molten pool at the beginning of the blowing, the oxidation of silicomanganese and a small amount of iron in the molten iron takes priority over the oxidation of carbon, so the rate of carbon oxidation is despite As the blowing time increases almost linearly, the oxidation rate of carbon is still very small. As the content of silicomanganese decreases and the temperature of the molten pool increases, the decarburization reaction intensifies and enters the middle of the blowing process. At this time, the decarburization reaction rate is basically constant. This is because the rate of carbon oxidation increases significantly when the temperature of the molten pool increases. Large, its decarburization rate almost only depends on the intensity of oxygen supply. When the carbon content drops to a certain level, the diffusion rate of carbon decreases and becomes the control link of the reaction. Especially when the carbon drops below 0.20%, the oxidation rate of carbon drops sharply. At this time, the oxidation rate of carbon is similar to that of the initial stage of blowing, but depends on the concentration and diffusion rate of carbon, and is proportional to the carbon content.