Nickel-Base High-Temperature Corrosion
Nickel-base high-temperature corrosion occurs at extreme temperatures due to gaseous reaction products. Chromium and aluminum alloying protect against this corrosion by forming an oxide layer.
Physical-Chemical Mechanism of Action
At extreme temperatures, nickel superalloys react with gaseous species like oxygen and sulfur dioxide. This leads to corrosion and a loss of mechanical properties.
Metallurgical Relevance & Welding Risks
High-temperature corrosion can cause a big drop in strength and toughness, shortening part life. It also raises the risk of cracking and wear issues. Not enough chromium or aluminum in the alloy can speed up corrosion.
Workshop Practice & Action Items
To prevent high-temperature corrosion, make nickel superalloys with the right amounts of chromium and aluminum. Run welding processes under tight temperature control to get a uniform oxide layer on the surface. When picking materials, make sure they suit the specific service conditions.