Long-term corrosion of austenitic steels in flowing LBE at 400 degrees C and 10(-7) mass% dissolved oxygen in comparison with 450 and 550 degrees C

摘要

Long-term corrosion tests for up to similar to 13,194 h on 1.4970 (15-15 Ti), 316L and 1.4571 austenitic steels were carried out at 400 degrees C in flowing LBE (2 m/s) with 10(-7) mass% dissolved oxygen. The steels show general slight oxidation (Cr-based oxide film) along with local, pit-type solution-based corrosion attack. The incubation time for pit-type attack is similar to 4500 h. After similar to 13,194 h, the maximum pit depth observed was similar to 14, 23 and 57 mu m for 1.4970, 316L and 1.4571, respectively, that corresponds to local corrosion rates of similar to 6, 10 and 26 mu m/year. At 450 degrees C and 550 degrees C, the corrosion rates are ranged in between similar to 120-220 mu m/year and similar to 500-3000 mu m/year, respectively. Corrosion appearances and mechanisms are discussed. (c) 2015 Elsevier B.V. All rights reserved.