Characterization of stainless steel 304 tubing

Technical Report · Mon Oct 16 04:00:00 EDT 1995

DOI:https://doi.org/10.2172/125388· OSTI ID:125388

Sunwoo, A J; Brooks, M A; Kervin, J E

Earlier studies have shown that stainless steel 304 (SS304) containing martensite is susceptible to hydrogen embrittlement. This generated concern regarding the structural integrity of SS304 tubing we use in the W87 pit tube. During surveillance operations, the pit tube undergoes a series of bending and straightening as it goes through a number of surveillance cycles. This motivated the study to characterize austenitic SS304 tubing obtained from Rocky Flats. The tubes continued to display structural soundness even after numerous repeated bending and straightening cycles. The minimum and maximum number of bends to failure occurred after 13 and 16 cycles, respectively. After 5 bends, both the inner and outer surfaces of the tubing showed no microcracks. When the bent tubing samples were pressurized and tested using deuterium at 74{degrees}C and at {approximately}78{degrees}C, they failed away from the bent area. Thus deuterium embrittlement of the bent SS304 tubing should not be a problem. Moreover, to increase our 95% confidence level to 5 bends, we are planning to perform at least four additional bends to failure tests.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 125388
• Report Number(s): UCRL-ID--122234; ON: DE96002163
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BENDING
CRACKS
DEFORMATION
DEUTERIUM
HYDROGEN EMBRITTLEMENT
MARTENSITE
MICROSTRUCTURE
STAINLESS STEEL-304
TENSILE PROPERTIES
TUBES
YIELD STRENGTH