Feeding speed has a great influence on calcium absorption rate. Both too fast speed and too slow speed will cause the decrease of the absorption rate. The cored wire starts to melt when it is fed to a certain depth. Its depth should ensure that the melted and dispersed calcium bubbles are subject to the greater static pressure of the molten steel so that they will be consumed as completely as possible before they float to the molten steel surface. Appropriate feeding speed can increase the recovery rate of calcium. If the speed is too fast, on the one hand, the molten steel will violently churn due to the large amount of calcium vapor generated locally, and a large amount of calcium vapor will directly volatilize into the air; on the other hand, the calcium vapor will float up in a large amount without time to dissolve, thereby reducing its yield. On the contrary, if the speed is too slow, the feeding depth will be insufficient, and it will float to the molten steel surface before it can be completely dissolved in the molten steel and was wasted.
The calcium content of pure calcium core wire is much higher than that of cafe cored wire. If the same feeding speed is used, the molten steel will turn more violently, which is not conducive to calcium absorption. Different types of steel and different ladle capacities have different optimal feeding speeds, which need to be selected according to actual conditions.
The feeding position also has a great influence on the yield of calcium. The feeding point of the solid core pure calcium core wire should be selected at the center of the downflow of molten steel, as far away as possible from the argon blowing bright circle. In this way, whether calcium enters the molten steel in a gaseous state or in a liquid state, it will be forced to fall under the action of the downward flow, thereby prolonging its dwell time in the molten steel and making it fully absorbed by the molten steel.