THE ROLE OF CHLORIDE SALTS ON HIGH TEMPERATURE CORROSION OF 321 STAINLESS STEEL

The effect of CaCl2 and BaCl2 salt coatings on the high temperature corrosion of 321 stainless steel at 950 degrees C in a slow current of air for the period of 72 hours were studied. The 321 alloy was severely attacked by calcium- and barium-chlorides due to formation of volatile chlorides. The data have been complemented by oxidation kinetics measurements and morphological structures were analyzed using scanning electron microscope (SEM). The elemental distribution on the alloy surface deposits were characterized by using energy dispersive X-ray (EDAX) analysis. The alkaline earth metal chloride salts have deleterious effect on the protectivity of the scale and rapid degradation of the alloy is noted.