Corrosion and Slow-Strain-Rate Testing of Type 304L Stainless Steel in Tuff Groundwater Environments

摘要

Type 304L stainless steel (SS) is the nuclear waste package reference material by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The stress-corrosion cracking (SCC) resistance of this material to elevated-temperature tuff groundwater environments was determined under irradiated and unirradiated conditions. The material was found to be susceptible to SCC (in both the solution-annealed and solution-annealed-and-sensitized conditions) when exposed to an irradiated (3 x 10 sup 5 rad/h) air/water vapor/crushed tuff rock environment at 90 sup 0 C. A similar exposure at 50 sup 0 C did not result in failure after a 25-month test duration. Specimens of sensitized Type 304 SS failed in both the 90 sup 0 C and 50 sup 0 C environments. U-bend specimens of Type 304L SS conditioned with a variety of sensitization heat treatments resisted failure during a test of 1-year duration in which an environment of tuff rock and groundwater held at 200 sup 0 C was allowed to boil to dryness on a cyclical (weekly) basis. All specimens of sensitized Type 304 SS exposed to this environment failed. Slow-strain-rate studies were performed on 304L, 304, and 316L SS specimens. The Type 304L steel was tested in J-13 well water at 150 sup 0 C; the Type 316L steel at 95 sup 0 C. Neither material showed evidence of SCC in these tests. Sensitized Type 304 SS, on the other hand, did exhibit SCC in J-13 well water in tests conducted at 150 sup 0 C. (ERA citation 12:018550)