A study on the corrosion and stress corrosion cracking susceptibility of 310-ODS steel in supercritical water

摘要

General corrosion and stress corrosion cracking (SCC) susceptibility of an oxide dispersion strengthened (ODS) austenitic 310 (310-ODS) steel in supercritical water (SCW) are studied by weight gain and slow strain rate tensile (SSRT) testing, respectively. 310-ODS steel shows an excellent general corrosion resistance in SCW at 600 degrees C. Energy dispersive X-ray (EDX) and electron backscattered diffraction (EBSD) are conducted on the cross-section of the surface oxide film, revealing a double-layered structure. Results from SSRT tests at 600 degrees C show an intergranular fracture mode, and SCC susceptibility of 310-ODS steel increases with the increasing of dissolved oxygen (DO) concentration. SSRT tests at 650 degrees C show ductile fracture mode, and SCC susceptibility is minimum. ODS enhances the yield strength of 310-ODS steel to over 480 MPa, tensile strength to over 750 MPa, and still keeps elongation rate to over 12% at 600 degrees C. Combining with its low general corrosion rate and low SCC susceptibility, 310-ODS steel is supposed to be a promising material for the fuel cladding of supercritical water-cooled reactor (SCWR). (C) 2018 Published by Elsevier B.V.