A comparative study of the corrosion behavior of three stainless steels in an eutectic (Li,Na,K) 2CO 3 melt with and without (Na,K)Cl Additives at 973K in Air

Abstract

The ternary carbonate eutectic mixture of Li 2CO 3, K 2CO 3 and Na 2CO 3 as a heat transfer and storage medium has excellent thermophysical properties, but with high viscidity as compared with some other inorganic salts such as chlorides and nitrates. The addition of chlorides or fluorides to molten carbonates may improve their fluidity, but possibly making the melt become more corrosive. In this study, the corrosion behavior of type 304, 310 and 316 stainless steels in an eutectic (Li,Na,K) 2CO 3 melt with and without an eutectic mixture of NaCl and KCl at 973K in air have been examined. The experimental results indicated that 310 steel shows a much better corrosion resistance in molten carbonates than both 304 and 316 steels, due to the formation of a continuous LiCrO 2 scale. The addition of chlorides to carbonates melt accelerated the corrosion of the steels, especially 310 steel, producing scales with more porosity. © 2011 De Gruyter.