Stirring is an important step in steel liquid treatment and also the most important step. Stirring can mainly reduce the segregation of the constituents in steel liquid and make the components of steel liquid uniform. And only stirring can produce flocs of steel liquid that meet the requirements of deoxidation and desulfurization, and thus achieving the effect of refining. The stirring process usually takes about 10 to 12 minutes.
The stirring process has some requirements. The first requirement is that there should be no entrainment of foreign substances or air during stirring. It is best to stir with an inert gas (such as nitrogen) to prevent the oxidation of molten steel caused by the oxidation of contact with air. The second requirement is that the stirring speed should be moderate and uniform. Too fast or too slow a speed is not conducive to stirring. The third requirement is to reduce the mechanical power consumed on stirring and avoid the oxide forming of steel liquid. The stirring rod should be used to mix the steel liquid in a vertical direction, so as to evenly distribute the reactive species in the steel liquid.
It should be noted that generally a heavy bottomed ladle should be used for stirring. It is not suitable to use a small cutting ladle or other shaped ladle. This is because the bottom of the heavy bottomed ladle is flat and wide, and the stirrer is easier to move around when it is deployed in the ladle. Finally, it is important to note that hydrogen in steel should be reduced to an appropriate value during stirring. If too much hydrogen accumulates in the steel liquid, the desulfurization effect cannot be achieved.
In short, stirring is one of the important steps in steel-making. It has the function of promoting deoxidation and desulfurization, and reducing the segregation of the components of the steel powder. Therefore, the steel plant should pay attention to the lag of stirring, the condition of the stirrer, the choice of the ladle, and the hydrogen content of the steel. To ensure that the quality of the steel liquid is up to standard, and achieve the goal of making qualified steel.
