Influence of temperature on the interaction mode of T91 and AISI 316L steels with Pb–Bi melt saturated by oxygen

Abstract

Corrosion tests of T91 and AISI 316L steels in stagnant Pb–Bi eutectic saturated by oxygen at 500, 520, 540 and 560 °C were carried out. The corrosion mode as a function of temperature was revealed. The oxidation was the main interaction mechanism for both T91 and AISI 316L steels. At 560 °C temperature the interaction mode for AISI 316L was mixed: the oxidation as well as the dissolution of steel components accompanied by the penetration of liquid metal into the solid metal was observed simultaneously. The corrosion rate of AISI 316L steel was less than that of T91 due to higher content of chromium in the austenitic steel. However, the spinel layer containing Ni was more vulnerable to the liquid metal attack. The kinetic model describing nucleation, growth and degradation of double oxide layer on the surface of steels contacting with Pb–Bi melt saturated by oxygen was proposed.