Vacuum degassing is a process used in different industries, especially the metallurgical industry, to remove dissolved gases from liquids or molten materials. In steel production, it is used to remove gases such as hydrogen, oxygen and nitrogen, which can harm the mechanical properties and quality of steel. The process involves exposing the material to a vacuum (low pressure) environment to facilitate the release and removal of these gases. This method is essential for manufacturing high-quality steels, as residual gases can cause defects such as porosity, brittleness, and strength problems.
Vacuum degassing has evolved significantly since its inception. In the 1930s, the steel industry began researching how to remove harmful gases from molten steel, but it was not until the 1950s that efficient technologies were developed for this purpose. Technological progress and the increasing demand for high-quality steels prompted the creation of more sophisticated methods, such as the Ruhrstahl-Heraeus (RH) process and the Vacuum Oxygen Decarburization (VOD) process, which optimized gas removal and significantly improved properties. of steel.
Vacuum degassing technologies in the metallurgical industry are diverse and have been developed to optimize the removal of gases dissolved in steel and other molten metals. Some of the most important technologies include:
Other less used processes are: Vacuum Tank Degassing (VTD) Process, Vacuum Ladle Degassing (VLD) Process, Vacuum Carbon Deoxidation (VCD) Process and the Electroslag Remelting Process (ESR).
Each of these technologies offers specific advantages and is chosen according to the requirements of the final product and the characteristics of the steel or alloy to be produced. Proper selection of the degassing process is crucial to obtain high-quality materials with optimal mechanical and chemical properties.
The process of degassing steels under vacuum involves several steps and these can vary depending on the technology used. An example of a typical process could be:
Machinery used for vacuum degassing includes:
Vacuum degassing has multiple applications and benefits in the industry, including: