argon-oxygen decarburization

The argon-oxygen decarburization (AOD) process is a method used in metallurgy, specifically for producing stainless steel and other high-alloy steels. When producing these steels, it's crucial to reduce carbon levels without oxidizing valuable alloying elements like chromium. The AOD process achieves this by injecting a mixture of argon and oxygen into the molten metal. The argon dilutes the oxygen, lowering its partial pressure. This encourages the oxygen to react primarily with carbon, minimizing the oxidation of other alloys.12

The process involves blowing gas mixtures through the molten steel in a converter. Initially, a higher concentration of oxygen is used, and as carbon levels decrease, the proportion of argon is increased. This controlled process allows for a significant reduction in carbon content while preserving the alloying elements. Argon is also used at the end of the process to help remove hydrogen and nitrogen from the steel.1