20G High Pressure Boiler Tube Production Process: Smelting Process

20G High Pressure Boiler Tube Production Process: Smelting Process

150 ton very high power electric arc furnace smelting ----> ladle refining ----> wire feeding ----> six-strand continuous casting
In electric arc furnace smelting, eccentric bottom tapping is adopted to reduce temperature drop and secondary oxidation of molten steel; it is equipped with oxygen oil burner, oxygen blowing aids melting, reduces melting time and saves energy consumption; adopts foam slag smelting, which can carry out long arc Buried interoperability can not only save electrodes, but also limit the increase of nitrogen and hydrogen in the molten steel to reduce the oxygen content; the whole process is controlled by computer to optimize the smelting process.

During refining, Ar gas was blown at the bottom of the bag to stir. In this way, the composition of molten steel is not only uniform, but also conducive to degassing and floating of inclusions to further purify molten steel.

There are two wire feeding machines, which can feed Al wire and Si-Ca wire. Feeding wire can not only be used for composition fine-tuning, desulfurization, deoxygenation, removal of inclusions and change of inclusion status, but also to avoid nodules at the nozzle of continuous casting.
According to the characteristics and standard requirements of 20G steel, the smelting process is formulated, and the range of internal control components is specified. Taking S and P as an example, the internal control components are required to be P≤0.020% and S≤0.015%. The temperature control range of continuous casting ladle molten steel is determined after the electric arc furnace tapping and ladle refining are completed, so as to ensure the surface quality of the continuous casting billet.

The continuous casting machine is arc-shaped six-strand continuous casting, equipped with a butterfly-type ladle turntable, which can be continuously poured with steel types in multiple furnaces.