Accelerated Hot Corrosion Studies of D-Gun-Sprayed Cr2O3–50% Al2O3 Coating on Boiler Steel and Fe-Based Superalloy

The weight gain of coated specimens after cyclic hot corrosion was less than the uncoated ones.

“As a result, the weight gain of coated specimens after cyclic hot corrosion was less than the uncoated ones.”

The Kp values of coated T-22 and 800H specimens were 72.77 × 10-8 g2 cm−4 s−1 and 0.39 × 10−8 g2 cm−4 s−1, respectively.

“The Kp values of coated T-22 and 800H specimens were 72.77 × 10–8 g2 cm−4 s−1 and 0.39 × 10–8 g2 cm−4 s−1, respectively.”

D-gunTM Cr2O3-Al2O3 coatings on T-22 boiler steel and 800H superalloy formed oxide scales of Al2O3 and Cr2O3 as protection against molten Na2SO4-V2O5 at 900 °C, resulting in intact coatings after 50 cycles of exposures.

“Rani et al. [118, 119] studied the corrosion behaviours of D-gun™ Cr2O3–Al2O3 coatings on T-22 boiler steel and 800H superalloy in molten Na2SO4–V2O5 at 900 °C. Coatings on both the substrates formed oxide scales of Al2O3 and Cr2O3 as protection against the molten salt mixture, resulting in intact coatings after 50 cycles of exposures.”

The only ceramic that has been exploited D-gunTM applications is Cr2O3-Al2O3.

“The only ceramic that has been exploited D-gun™ applications is Cr2O3–Al2O3 [118, 119].”

Kp of T-22 steel coated with the Cr2O3-Al2 was reduced to 0.06 × 10-8 g2 cm−4 s−1 and Kp of coated 800H superalloy was reduced to 0.24 × 10-8 g2 cm−4 s−1.

“However, Kp of T-22 steel coated with the Cr2O3–Al2 was reduced to 0.06 × 10–8 g2 cm−4 s−1 and Kp of coated 800H superalloy was reduced to 0.24 × 10–8 g2 cm−4 s−1.”