How to Make Steel in an Electric Arc Furnace?

How to Make Steel in an Electric Arc Furnace?

Overview of the Electric Arc Furnace Steelmaking Process

At present, more than 95% of the world's electric furnace steel production is produced by electric arc furnaces, so electric furnace steelmaking mainly refers to electric arc furnaces. Electric furnace steelmaking uses scrap steel as the main raw material, three-phase alternating current as the power source, and uses the high temperature of the arc generated by the current passing through the graphite electrode and the metal material to heat and melt the furnace charge. The electric arc furnace is the main method for producing special steel and high alloy steel (now also used to produce ordinary steel).

Features of Electric Arc Furnace Steelmaking:

1. Electric energy is used as the heat source to avoid the pollution of the steel industry caused by burning fuel, and the thermal efficiency is high, which can reach more than 65%.

2. The temperature of the smelting pool is high and easy to control, meeting the requirements of different steel grades.

3. During the electric heat conversion, the power input to the molten pool is easy to adjust, so it is easy to realize the automation of the solution heating temperature, and the operation is convenient.

4. Electric arc furnace steelmaking can digest scrap steel. It is a process of recycling and reusing iron resources, and it is also an environmentally friendly technology for dealing with pollution. It is equivalent to a recycling tool for scrap steel in the steel industry and society.

5. The smoke pollution and noise pollution in the steelmaking process are easy to control.

6. The equipment is simple, the steelmaking process is short and occupies less space, the investment is low, the plant construction is fast, and the production is flexible.

With the advancement of steelmaking technology, the functions of traditional converters and electric furnaces are also changing. The functions of modern electric furnaces have gradually evolved into fast and efficient decarbonizers, fast temperature risers, energy converters, and optimized dephosphorizers. The functions of modern electric arc furnaces have also evolved into: fast scrap melting, fast molten pool heating, Zhan energy conversion, efficient decarbonization and dephosphorization, and recycling of waste plastics and tires.

Advances in Electric Furnace Steelmaking Technology

The traditional electric arc furnace steelmaking operation integrates charge melting, steel liquid refining, and alloying in the same molten pool. It has to go through "three stages", which requires the furnace to complete melting, dephosphorization, decarburization, and heating, as well as deoxidation, desulfurization, degassing, deinclusion, alloying, and temperature and composition adjustment. The smelting cycle is long. The modern electric arc furnace steelmaking process retains melting, heating, and necessary refining operations, and puts the rest into secondary refining. The process improvement has improved the capacity of the electric arc furnace equipment, enabling it to perform melting and heating operations with the greatest possible power, and transfer operations that only require lower power to the ladle refining furnace. The increasingly improved secondary refining technology can fully meet the requirements of steel liquid cleanliness and strict composition temperature control.

Arc furnace Steelmaking and Alloying Methods

Non-oxidation Smelting

It can be used when the quality of steel raw materials is good (less rust, no dephosphorization is allowed, but it is required that [C] and [P] should reach the end of the melting process without oxygen oxidation, no boiling decarburization and degassing, and the heating time is only about 15 minutes. Therefore, this method requires a short time and low power consumption. It is an economical smelting method.

Return Smelting

The raw materials used can be mixed with return steel, In order to increase the recovery rate of gold elements, some reducing materials can be added to the slag surface during the heating stage to reduce the oxides of chromium, manganese, vanadium, etc. This method saves the consumption of precious metal alloy elements and electricity, and reduces costs.

Return Oxygen Blowing Smelting

A special method for smelting carbon low-chromium high-stainless steel. The raw materials composed of this steel type and other alloy return steels belong to the chromium non-oxidation method return smelting under high temperature conditions, retaining most of the chromium. This method is often used to produce steel types with strict requirements on sulfide inclusions, high-speed steels and high-chromium tungsten tool steels.