LAUSR

Abstract Liquid tin (Sn) is a promising coolant for liquid divertor concepts. However, its material compatibility with structural materials is an important issue. The purpose of the present study is to investigate corrosion resistance of Al-rich steel NTK04 L (Fe-17.7Cr-3.3Al-0.4Si) and Al2O3 ceramic bulk in liquid Sn. The oxidation treatment of the steel surface was performed in air at 773 K for 645 h in order to form an Al-rich oxide layer on its surface. The specimens of the Al-rich steel with and without the Al-rich oxide layer were immersed in liquid Sn at 773 K for 262 h. The corrosion test with Al2O3 ceramic bulk was also performed at the same conditions. After the corrosion tests, the specimen surfaces were metallurgically analyzed by FE-SEM/EDX, EPMA and AES. The steel which had the Al-rich oxide layer revealed corrosion resistance, though a very limited area of the surface was corroded according to the formation of Fe-Cr-Sn intermetallic compound. The Al2O3 ceramic bulk revealed corrosion resistance in liquid Sn, though small chemical reaction involving Ni impurity was detected on its surface.