Steel production process

The task of steelmaking: refining iron ore into qualified steel.. The indirect steelmaking method is the main steelmaking method currently used.

1. The blast furnace is a device that uses coke to reduce iron ore to produce pig iron. Product of blast furnace ironmaking: molten iron

1.1 The role of the hot blast stove is to provide the blast furnace with combustion-supporting hot air, saving coke. According to on-site experience, for every 100℃ increase in wind temperature, the coke ratio per ton of iron can be reduced by about 20Kg, and production can be increased by nearly 5%.

2. The function of the torpedo car is to transport molten iron from the blast furnace to the converter or electric furnace, and also to pre-treat the molten iron (desulfurization, dephosphorization, desilification).

Steelmaking principle

Steelmaking: By smelting, the carbon in pig iron is reduced and harmful impurities are removed. Then, according to the requirements for steel properties, an appropriate amount of alloying elements is added to make it steel with high strength, toughness, or other special properties.

Basic tasks of steelmaking:

1. Decarbonization and adjusting its content to a certain range

2. Dephosphorization, decarbonization, deoxidation, removal of gases and non-metallic inclusions

3. Adjusting the steel liquid composition and temperature

4. Casting the steel liquid into high-quality steel ingots and billets

Steelmaking methods

Converter steelmaking method: The raw materials used are molten pig iron and scrap steel

Electric furnace steelmaking method: The raw materials used are sponge iron or scrap steel, which has broad development prospects.

Ladle metallurgy

Ladle metallurgy refers to the refining tasks traditionally completed in conventional steelmaking furnaces, such as removing impurities from the molten steel (including unwanted elements, gases, and inclusions), adjusting and homogenizing the composition and temperature, being partially or wholly transferred to the ladle or other containers. Therefore, ladle metallurgy is also called secondary refining, ladle metallurgy, or ladle refining.

Ladle metallurgy

LF (Ladle Furnace Refining Method)

ASEA-SKF (Ladle Vacuum Refining Method)

VOD (Vacuum Oxygen Decarbonization Method)

VAD (Vacuum Arc Heating Degassing Furnace)

RH (Vacuum Treatment)

DH (Vacuum Treatment)

Steel casting:

Steel casting is the process of pouring the qualified molten steel obtained in the steelmaking furnace and ladle metallurgy into steel ingot molds or crystallizers of a certain shape and size through ladles and tundishes, so that it solidifies into the final product of steelmaking—steel ingots or billets.

Continuous casting: Continuously casting molten steel into billets through a continuous casting machine without the initial rolling process, and directly sending it to the rolling mill for rolling into steel.

The tundish is an intermediate storage device for molten steel flowing from the ladle to the crystallizer in the steelmaking continuous casting process, suitable for the transition of molten steel between the ladle and the crystallizer.

Functions of the tundish:
Accepting molten steel flowing from the ladle and stabilizing the molten steel flow; distributing the molten steel into several streams, with nozzles at the bottom corresponding to the number of streams in the continuous casting machine, reducing the erosion of the shell in the crystallizer by the steel stream, controlling the amount of molten steel injected into the crystallizer, which is beneficial for the flotation of non-metallic inclusions and improves the casting quality