Continuous Casting Billet Drumming
Continuous casting billet drumming is the process of violently vibrating the continuous casting billet while being cooled in the mold. It is a process that aims to provide uniform temperature across the entire cross section to provide uniform cooling and shrinkage. The uniform temperature across the cross section is beneficial to the strength and microstructure of the billet.
The continuous casting billet drumming process is usually implemented after the billet is transferred to the drum. The drum is a rotating cylinder with ribs inside that vibrate against the billet wall. The billet is surrounded by cooling liquid and the drum movement allows for the transfer of the heat from the billet to the liquid itself. This is beneficial for the uniform cooling as the maximum cooling of the liquid occurs at the highest possible rate due to the fast rotation of the drum.
The drumming operation also helps reduce defects in the billet while providing the necessary cooling conditions. This operation helps to protect the billet against heat-induced strain, which can lead to tearing and slag inclusions. The drumming also helps to reduce surface irregularities that occur due to differences in cooling rate across the cross section. These irregularities could lead to cracks in the billet when it is shipped.
Billet drumming is a critical part of the continuous casting process and should take place as close to the end of the production line as possible. This allows the molten metal to have time to cool so that vibrations during the drumming operation do not create any further defects in the metal. The drumming operation also helps to remove excess liquid from the surface of the metal and, in some cases, helps to reduce residual oxides.
Using incorrect drumming parameters can lead to an increase in surface defects, mechanical properties, strength, and machinability. It is essential that these parameters are optimized for each billet configuration and material composition to ensure a product of the highest quality. The parameters that need to be optimized include the size of the drum, frequency, and amplitude.
Given the importance of the drumming operation for the continuous casting billet, it is essential that the operation is carried out in accordance with all safety regulations. The drums should have guards in place to protect against any pieces coming off during the drumming operation. The hazes generated while drumming can be dangerous and should be kept to a minimum by always following safety protocols.
