High-Temperature Oxidation
Hot gas oxidation is a chemical reaction where metals react with gaseous oxygen molecules, forming a thin oxide layer on the surface. This occurs especially at high temperatures and can affect material resistance.
Physical-Chemical Mechanism
At elevated temperatures, metals such as steel react with gaseous oxygen (O₂) and form a thin layer on the surface. This process is particularly active at high temperatures and can lead to grain coarsening.
Metallurgical Relevance & Welding Risks
Hot gas oxidation can impair the strength and toughness of steels. It can also lead to corrosion and cracking, especially if the material is not well protected or during prolonged processes. This increases the risk of hot cracking and reduces weld lifespan.
Workshop Practice & Action Items
To avoid hot gas oxidation, metals should be protected at high temperatures. This can be done by using shielding gases like argon or by keeping the material in a closed system. For prolonged processes, it is important to reduce oxygen content in the environment and regularly cool the material.