High-Temperature Oxidation
Hot gas oxidation is a chemical reaction of metals with oxygen at high temperatures, without liquid electrolytes. It affects material life and behavior.
Physico-chemical mechanism of action
Hot gas oxidation is a direct chemical reaction of metals with oxygen at elevated temperatures, without the need for a liquid electrolyte. This process can be caused by diffusion of oxygen molecules into the metal and formation of an oxide layer.
Metallurgical relevance & welding risks
Hot gas oxidation can coarsen the metal, impairing its mechanical properties. It can also cause corrosion and cracking, especially if the material is not well protected. This can significantly shorten the life of welds and components.
Workshop practice & procedure
To avoid or minimize hot gas oxidation, take the following steps:
• Use high-quality protective coatings such as silicon-copper (SiCu) or chromium-copper (CrCu).
• Keep welding temperatures as low as possible to slow oxidation.
• Use shielding gases like argon or helium to protect the metal from oxygen.