LF Refining Furnace multi-effect refining agent (auxiliary slag-making material) is a molten steel refining process technology, which is applied to the refining process of foaming white slag in the reducing (or weakly oxidizing) atmosphere of refining slag.
It is a low-cost smelting high-quality steel grade. The invention relates to a steel-making method, which belongs to the field of refining outside the molten steel furnace.
Compared with the existing LF refining furnace slag-making technology, the effect of the multi-effect refining agent in the LF refining furnace has the following effects:
1. The elements of Ca, Al, Si, and C in the functional components of the multi-effect refining agent in the ladle refining furnace have strong deoxidation ability, which can meet the requirements of rapid and deep deoxidation of slag and diffusion deoxidation of molten steel. Refining slag (FeO+MnO) ^ 1%, molten steel  ( 16ppm）.
2. The deoxidized element product can form a white slag ore phase with the synthetic slag component, which is beneficial to the desulfurization of molten steel and the removal of inclusions. In the synthetic slag, the main component lime activity degree is under the condition of 280mol/ml (40 ± rC, 10min), refining slag Ls≤140, desulfurization rate≤81.6%, improve 15% than existing technology; The total amount of inclusions is less than 65ppm, which is more than 25ppm lower than the existing technology.
3. The functional component of the multi-effect refining agent in the LF ladle refining furnace has a strong foaming function and is equipped with a slow-release agent that inhibits the foaming speed and gas escape.
At home and abroad, carbonates (such as & 0) 33 and 03 are usually used as foaming agents. In view of the poor stability of such foaming agents and the drawbacks of secondary oxidation of steel slag produced by (X)2.
In this design, this type of foaming agent is discarded, and only the weak oxidizing (reducing) of the slag and the co2 and co (mainly CO under the reducing and high-temperature conditions of the refining slag) produced by C in the functional components are used as the foaming agent. Air source for foam slag.
Then, by adding a slow-release agent that inhibits the foaming speed and gas escape, the slow-release agent can stably (its effect does not change much with temperature), improve the viscosity and surface tension of the slag, and reduce the CO2, CO (mainly CO2 and CO2) produced by the foaming agent. CO) is encapsulated in the slag with higher viscosity and surface tension for a longer period of time.
The practice has proved that when the addition of multi-effect refining agent in LF ladle refining furnace is 0.5~0.
The complete submerged arc refining of the refining furnace is ensured, resulting in two aspects of effects:
1. Reduce the content of [N] and [H] in molten steel during LF refining. Because N2 and H2O in the air are dissociated into N and H atoms by arc, they are easily dissolved in molten steel, so the technology of fully submerged arc foam slag can greatly reduce the content of N and H in steel. Under the condition that the air humidity is more than 95, the molten steel at the end of the ladle refining furnace [N] is less than 45ppm, which is more than 25ppm lower than the existing technology; [H] (3.8ppm, which is more than 1ppm lower than the existing technology.
2. Reduce consumption and cost. Improve the thermal efficiency of electric energy, saving more than 20% of power consumption; reduce the oxidation burning loss of electrodes, saving more than 15% of electrode consumption; At the same time, it also reduces the erosion of the arc on the refractory material of the ladle slag line. For steel grades that do not require very high refining sulfur, the consumption of synthetic slag can be reduced by about 40%.
LF refining furnace multi-effect refining agent (auxiliary slag-forming material) in the refining slag reducing (or weakly oxidizing) atmosphere to make molten steel refining technology to foam white slag, including the design of the multi-effect refining agent in the ladle refining furnace, the preparation of the components, the amount of addition, the method of addition and other process technologies.