13 steps of electric arc furnace steelmaking-part 1

Electric arc furnace charging

The operation of adding raw materials such as molten iron or scrap steel to the electric furnace is the first step of the electric furnace steelmaking operation.

Slagging

The operation of adjusting the slag composition, alkalinity, viscosity and reaction ability in the production of steel and iron. For example, the oxygen blowing operation is to generate slag with sufficient fluidity and alkalinity, which can transfer enough oxygen to the metal surface, so as to reduce the sulfur and phosphorus below the upper limit of the planned steel grade, and make the oxygen spray splash The amount of slag and spillage is minimized.

Slag

The operation of slagging or slagging in the smelting process according to different smelting conditions and purposes during electric arc furnace steelmaking. For example, when single slag method is used for smelting, oxidation slag must be removed at the end of oxidation; when double slag method is used for reducing slag, the original oxidation slag must be completely released to prevent phosphorus from returning.

Molten pool stirring

Supply energy to the molten metal pool to make the molten metal and slag move to improve the kinetic conditions of the metallurgical reaction. The stirring of the molten pool can be achieved by means of gas, mechanical, electromagnetic induction and other methods.

Electric arc furnace dephosphorization

Reduce the chemical reaction of the phosphorus content in molten steel. Phosphorus is one of the harmful impurities in steel. Steel with a lot of phosphorus, when used at room temperature or lower, is prone to brittleness, which is called "cold brittleness". The higher the carbon content in steel, the more serious the embrittlement caused by phosphorus. Generally, it is stipulated that the phosphorus content of ordinary steel does not exceed 0.045%, and high-quality steel requires less phosphorus.

Electric furnace bottom blowing

Through the nozzle placed at the bottom of the furnace, N2, Ar, CO2, CO, CH4, O2 and other gases are blown into the molten pool in the furnace according to the process requirements to achieve the purpose of accelerating the melting and promoting the metallurgical reaction process. The bottom blowing process can shorten smelting time, reduce power consumption, improve dephosphorization and desulfurization operations, increase the amount of residual manganese in steel, and increase the yield of metals and alloys. And it can make the composition and temperature of molten steel more uniform, thereby improving steel quality, reducing costs and increasing productivity.

Melting period of electric furnace steelmaking

The melting period of steelmaking is mainly for open hearth and electric furnace steelmaking. The melting period of electric arc furnace steelmaking is called the melting period from the start of electrification to the complete melting of the steel spikes and the open-hearth furnace steelmaking from the completion of the molten iron to the completion of the charge. The task of the melting period is to melt and heat up the charge as soon as possible, and make the slag in the melting period.