Short-Term Corrosion Behavior and Mechanism of 316 Stainless Steel in Liquid Pb at 650 and 750 °C

The corrosion behavior and mechanism of 316 stainless steel (316SS) immersed in liquid Pb were investigated in Ar at 650 and 750 °C, respectively. The oxidation corrosion first dominated at 650 °C. The outer layer of the corroded 316SS surface was the loose iron oxide layer, and the inner layer was dense Fe-Cr spinel. However, the selective dissolution of Ni and Cr was dominant at first at 750 °C, and the O diffused to the interface increased with time, then an inner oxide layer is formed with Ni, Cr, and Fe in inner layer of the matrix. The sizes of pores formed by the dissolution gradually increased with the corrosion time increase, and the dissolved area was also partially transformed into the whole. The selective dissolution corrosion of the corroded 316SS was dominant at 750 °C with the time increase. The interaction mechanism between the liquid lead and 316SS was revealed.