Investigation on the hot corrosion behavior of a single crystal Ni-based superalloy in molten Na2SO4+K2SO4 salts improved by different preoxidation treatments

This study investigated the hot corrosion behavior of N5 in molten sulfate at 850 & DEG;C after different peroxidation treatments. The preoxidation was conducted at 900, 1000 and 1100 & DEG;C for 20 and 100 h, respectively. The preformed oxide scale featured a multilayered structure and varying degrees of Ta oxides. Among all, the samples preoxidized at 900 & DEG;C exhibited the highest corrosion resistance. But a porous structure with a large number of internal oxides and sulfides was observed when preoxidized at 1000 and 1100 & DEG;C. The alloy without preoxidation directly reacted with the molten salt to form a porous structure with internal oxides and sulfides.

Automated summary

This study investigates the hot corrosion behavior of N5 alloy in molten sulfate at 850°C after different peroxidation treatments. Preoxidation was performed at 900, 1000, and 1100°C for 20 and 100 hours, respectively. The preformed oxide scale had a multilayered structure and varying amounts of Ta oxides. Among all the samples, those preoxidized at 900°C exhibited the highest corrosion resistance. However, a porous structure with internal oxides and sulfides was observed when preoxidized at 1000 and 1100°C. The alloy without preoxidation directly reacted with the molten salt to form a porous structure with internal oxides and sulfides.