Corrosion behavior of a 304-oxide dispersion strengthened austenitic stainless steel in supercritical water

Abstract

The corrosion behavior of a 304 oxide dispersion strengthened (ODS) austenitic stainless steel after being exposed to supercritical water (SCW) with dissolved oxygen of 300 ppb at 600 8C/25 MPa was studied. By the means of a least-square fit, the weight gain (Dw) of the samples as a function of exposure time (t) could be described by the equation Dw ¼ 8.011 Â t 0.459 . An approximately parabolic time law in this specified SCW environment can be assumed. A triple protective oxide layer formed on the surface of the metal with the exposure time up to 1000 h. Furthermore, the result of slow-strain rate tensile (SSRT) test indicated that the 304-ODS austenitic stainless steel was not susceptible to stress corrosion cracking (SCC) in SCW at 600 8C/25 MPa.

Chloride-Induced Stress Corrosion Cracking of Oxide-Dispersion-Strengthened Austenitic Steels

“…Li, et al, investigated the corrosion and SCC behaviors of ODS 304 austenitic steels in a supercritical water (SCW) environment at 600°C by slow strain rate tensile (SSRT) tests. 24 The corrosion kinetics of ODS 304 steels followed a parabolic law, as a result of the formation of a multilayer protective oxide scale. The fracture mode of ODS 304 steels was unchanged from the conventional 304 steels, with a mixed fracture mode of brittle cleavage and ductile dimple in the SCW environment.…”