LUNG AN Stainless

Smelting and Refining Technology

2015.01.21

In stainless steel production, there are three kinds of smelting processes. This is because the chemical composition of every stainless steel product reacts differently in terms of resistance to corrosion. Corrosion can be caused by air, water, acid, salt, team, alkali, and chemicals so knowing what is used in creating something made from stainless steel would help you determine which of the 3 kinds would work best.

 

Steel Smelting using electric furnace – This was once considered the most efficient way of stainless steel smelting and refining but over time with the energy costs and time it takes to complete a cycle, this process is no longer popular in many places. In addition, the quality of stainless steel products manufactured with the electric furnace is much more inferior with a short life term in refractory lining and low output.

 

The second process which came out around 1965 made use of a two step process. These were the Vacuum Oxygen Decarburization (VOD) and the Argon Oxygen Decarburization (AOD) refining technology. Almost 90% of all stainless steel manufacturing companies around the world use these methods, although majority prefers the AOD process.

 

The AOD uses a vessel that has a 3 step process in refining the stainless steel. These are Decarburization, Reduction, and Desulphurization. Decarburization simply means reducing the carbon content in the steel. Reduction is what is needed to prevent corrosion and Desulphurization is used to remove the sulfur dioxide. AOD was the brainchild of The Union Carbide Corporation in 1954.

 

The third kind of process is the use of the electric furnace but with advance VOD and Lance Bubbling Equilibrium or LBE. This allows for better anti-corrosion resistance and composition adjustment. However, the end result would still depend largely on the alloy elements used. LBE is a relatively new process for alloy melts. It has been described as “bottom stirring” and has been acclaimed for better results with lower slag volume and loss of metallics.