Corrosion behavior of base metal and weld bead of CLAM steel in flowing Pb-Bi at 550 °C

Corrosion behavior of base metal and weld bead of China low activation martensitic (CLAM) steel was studied in the flowing Pb-Bi at 550 degrees C. The corrosion tests were performed in an apparatus which was designed and manufactured by ourselves and could simulate the condition of corrosion test in the nuclear industry. CLAM steel is one of the reduced-activation ferritic/martensitic steels (RAFM) that is widely considered as the candidate structural metal for the new generation nuclear facilities. The flow velocity, corrosion temperature and corrosion time were 2.98 m/s, 550 degrees C and 1500 h, respectively. The corrosion test results indicate that a double-layer oxide film consisted of Fe3O4 outer layer and (Fe,Cr)(3)O-4 inner layer on surface of all the samples. The corrosion process of base metal and weld bead of CLAM steel in flowing liquid Pb-Bi included the oxidation-corrosion and erosion. The degree of oxidation-corrosion and erosion on the surface of the weld bead samples was more serious than that on the surface of the base metal, due the small grain size was related to greater corrosion resistance. The corrosion test results will provide a reference for the feasibility of the practical application of CLAM steel in the field of nuclear power in the future, and they will also provide data support for estimating the actual service life of CLAM steel.