Induction Furnace Slag

Induction Furnace Slag

During induction furnace smelting, the metal is heated by induction and then conducted to the slag, so the temperature of the slag is low, and the furnace structure determines that the steel-slag interface is small, which is not conducive to the physical and chemical reactions between the molten pool and the slag.

Therefore, when smelting special steel or nickel-based alloys, we should strive to use better raw materials, mix ingredients according to the burning loss of each element, and heat and melt quickly.

When a large amount of charge has been melted, slag should be added to reduce oxidation.

The slag should be compatible with the furnace lining.

After complete melting, according to the composition of the finished product, add deoxidizers (ferrosilicon powder, silicon calcium powder, aluminum powder, etc.) in batches, take samples for analysis, and adjust the composition if necessary.

When the composition is qualified and the deoxidation is good, the steel can be tapped.

Cast iron is not seriously oxidized during melting and heat preservation, and the metallurgical quality requirements are also relatively low, which can give full play to the advantages of the convenient operation of induction heating.

Compared with three-phase electric arc furnace smelting, the characteristics of induction furnace slag are as follows.

(1) The slag temperature is lower than the molten steel temperature

The heat source of the induction furnace is the heat from the induction current transformation inside the molten steel, and the slag is slag-formed and kept warm by the heat of the molten steel. Therefore, the slag temperature is lower than the molten steel temperature, also known as cold slag.

The electric arc furnace directly uses electric arc and electric current to heat the slag, and the temperature of the slag can be higher than the temperature of the molten steel. Due to the low temperature of induction furnace slag, its chemical reaction ability and effect are limited, which is the shortcoming of induction furnace smelting.

(2) The amount of slag is small, and the specific contact area of slag-steel is small

The amount of slag used in medium frequency induction furnace smelting is about 1% ~ 3%; the amount of slag used in electric arc furnace is about 3% ~ 5%, and the amount of slag used in dephosphorization is more than 5%. The specific contact area of slag-steel in electric arc furnace with large amount of slag is 3~5 times that of induction furnace. Therefore, its refining capacity is much greater than that of an induction furnace.

(3) The function of slag is less

According to different functions, electric arc furnace smelting can produce foam slag to play the role of slag covering, reduce power consumption, shorten smelting cycle, etc., and produce strong reducing slag such as white slag and carbide slag for diffusion deoxidation. Induction furnace smelting cannot achieve the predetermined metallurgical effect through different types of slag because of the low temperature of slag.