Which material corrodes the slowest in high-temperature helium?

Thread Content

Considering the previous background on corrosion by high-temperature helium, the Ni-20Cr series (modified nickel-chromium alloys with small additions of silicon, titanium, and niobium) is the material that shows the slowest corrosion rate according to the available experimental data. In the helium environment of simulated high-temperature gas-cooled reactors at 750–1050°C, these alloys exhibit significantly superior resistance to internal oxidation and carburization compared to the other tested alloys; no significant carbon penetration or peeling of the oxide layer was observed, and their corrosion rate was markedly lower than that of conventional nickel-based superalloys. Under the same testing conditions, the corrosion rate of Hastelloy X alloy is also extremely low, making it the best choice with the most balanced overall performance in industrial applications.