Kuumakorroosiota

Kuumakorroosiota is a Finnish term referring to a specific type of high-temperature corrosion. It is an accelerated oxidation process that occurs in metallic materials when exposed to corrosive gases at elevated temperatures, typically above 500 degrees Celsius. This phenomenon is particularly prevalent in environments containing sulfur compounds, such as those found in combustion processes, industrial furnaces, and gas turbines.

The mechanism of kuumakorroosiota involves the formation of molten salt layers on the metal surface. These salts, often sulfates or chlorides, are formed from the reaction of impurities in the fuel or combustion air with the metal oxides. The molten salt layer then acts as an electrolyte, dissolving protective oxide scales and facilitating the diffusion of corrosive species to the metal surface, thereby accelerating the attack.

Kuumakorroosiota can lead to significant material degradation, including pitting, cracking, and loss of mechanical integrity. This can result in premature failure of components, reduced efficiency, and increased maintenance costs. Materials commonly susceptible to kuumakorroosiota include nickel-based superalloys and stainless steels.

Preventive measures against kuumakorroosiota often involve material selection, coatings, and control of the corrosive environment. Using alloys with higher chromium and aluminum content can improve oxidation resistance. Protective coatings, such as ceramic or thermal barrier coatings, can act as a barrier between the metal and the corrosive environment. Minimizing the presence of sulfur and other corrosive impurities in fuels and combustion gases is also crucial.