Hot corrosion behavior of CM 247 LC alloy in Na2SO4 and NaCl environments

Hot corrosion studies of CM 247 LC alloy were carr icd out in pure sodium sulfate, as well as sodium chloride and sodium sulfate mixtures of different concentrations at various temperatures. A crucible test was employed to study the suitability of CM 247 LC as a gas turbine blade material. It was observed that bare CM 247 LC was severely , corroded in just 4 hr, while it was completely consumed in 70 hr when tested in 90% Na2SO4+10% NaCl at 900 degrees C, The results show that a chloride containing melt is more corrosive than pure sodium sulfate. The weight loss is linearly related to t(1/2) (time) and temperature in the different environments studied The corroded samples ere characterized by EPMA, SEM, XRD, and metallographic techniques, The results skew that hot corrosion of CM 247 LC is an electrochemical phenomenon.