Causes and solutions of steel slag accumulation in

Causes and solutions of steel slag accumulation in RH vacuum chamber

steel slag accumulation in RH vacuum chamber includes slag accumulation on the outer wall of oxygen lance, slag accumulation between hot top cover and middle groove, slag accumulation between middle groove and bottom groove, slag accumulation on hot top cover, etc. technical parameters of vacuum tension machine: the problem of steel slag accumulation in vacuum chamber will affect production stability, safety and product quality, which needs to be controlled

rh steel slag accumulation in the vacuum chamber includes slag accumulation on the outer wall of the oxygen lance, slag accumulation between the hot top cover and the middle groove, slag accumulation between the middle groove and the bottom groove, slag accumulation on the hot top cover, etc. the problem of steel slag accumulation in the vacuum chamber will affect the production stability, safety and product quality, which needs to be controlled

rh molten steel entering the station is generally divided into three types: the carbon and oxygen content of molten steel is suitable, the oxygen content of molten steel is too high, and the carbon content of molten steel is too high. When decarburizing in three ways, carbon and oxygen react violently and splash seriously, causing molten steel to stick to the wall of the vacuum chamber and the middle and bottom grooves

solution measures for slag accumulation in vacuum chamber

1. Control of vacuum degree

practice has proved that the faster the vacuum degree decreases, the more serious the splashing in vacuum chamber. In order to reduce splashing, pressure control is adopted in the early stage of treatment, and the vacuum degree is set at kPa to avoid splashing caused by too fast pressure drop

2. Optimize the pre deoxidation process

when the oxygen content in the steel is high and if steel and other boiling steel grades are produced, the treatment time is min. when the CO concentration reaches the peak, the reaction is the most intense. In order to control the splashing, aluminum or carburizing agent is usually used for pre deoxidation to remove the excess oxygen. According to the temperature of molten steel, different pre deoxidizers are used. When the temperature of molten steel is appropriate and aluminum oxide heating is not required, carburizing agents are used for pre deoxidization (added in batches); Otherwise, aluminum pre deoxidation is used

3. Control the lifting gas flow

with the beginning of vacuum pumping, the atmospheric pressure acting on the surface of the molten steel tank will raise the molten steel to a height of about 1.45M, and the lifting gas argon will be blown into the molten steel from the side wall of the rising insertion pipe. The argon bubble will expand rapidly under the action of high temperature, so that the density of molten steel will continue to decline along the height direction, and the molten steel will flow under the effect of density difference. The degassed molten steel returns to the ladle through the downcomer, realizing the continuous circulation of molten steel. Lifting gas is the driving force to realize refining of molten steel. On the premise of meeting the circulation of molten steel, reducing the flow of lifting gas can effectively reduce splashing. It must be 2 The signal is small. Have a comprehensive understanding of the performance of the product

4. Control the heating rate of aluminum oxide

in the production process, due to many factors affecting the temperature of molten steel, the OB rate of RH has been high, especially in the production of killed steel, during the heating process of RH, the slag accumulation on the hot top cover is obvious

the higher the OB rate is, the shorter the slag removal interval is, which indicates that the slag accumulation on the hot top is more serious. Therefore, to control splashing, it is necessary to reduce the RH heating ratio and range. For some steel grades with strict quality requirements (such as ultra-low carbon), it is necessary to increase the tapping temperature by ℃ or adopt duplex treatment (lf+rh) to reduce the RH heating ratio and range. In addition, shorten the transmission time of each process and reduce unnecessary temperature loss in 2012

in conclusion, reducing vacuum, using carburizing agent, increasing gas flow and reducing heating rate can reduce the formation of steel slag in RH vacuum chamber