Mechanical properties of thermally aged cast stainless steels from Shippingport reactor components

Technical Report · Sat Apr 01 00:00:00 EST 1995

DOI:https://doi.org/10.2172/71383· OSTI ID:71383

Chopra, O K; Shack, W J ^[1]

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1. Argonne National Lab., IL (United States)

Thermal embrittlement of static-cast CF-8 stainless steel components from the decommissioned Shippingport reactor has been characterized. Cast stainless steel materials were obtained from four cold-leg check valves, three hot-leg main shutoff valves, and two pump volutes. The actual time-at-temperature for the materials was {approximately}13 y at {approximately}281 C (538 F) for the hot-leg components and {approximately}264 C (507 F) for the cold-leg components. Baseline mechanical properties for as-cast material were determined from tests on either recovery-annealed material, i.e., annealed for 1 h at 550 C and then water quenched, or material from the cooler region of the component. The Shippingport materials show modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength because of relatively low service temperatures and ferrite content of the steel. The procedure and correlations developed at Argonne National Laboratory for estimating mechanical properties of cast stainless steels predict accurate or slightly lower values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predicted the mechanical properties of the Ringhals 2 reactor hot and crossover-leg elbows (CF-8M steel) after service of {approximately} 15 y and the KRB reactor pump cover plate (CF-8) after {approximately} 8 y of service.

• Research Organization: US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Div. of Engineering Technology; Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 71383
• Report Number(s): NUREG/CR-6275; ANL-94/37; ON: TI95012084; TRN: 95:015388
• Resource Relation: Other Information: PBD: Apr 1995
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
21 NUCLEAR POWER REACTORS AND ASSOCIATED PLANTS
REACTOR COMPONENTS
MECHANICAL PROPERTIES
SHIPPINGPORT REACTOR
RINGHALS-2 REACTOR
STAINLESS STEELS
RWE-BAYERNWERK REACTOR
FRACTURE PROPERTIES
MECHANICAL TESTS
IMPACT STRENGTH
TENSILE PROPERTIES
REACTOR MATERIALS
MICROSTRUCTURE
EXPERIMENTAL DATA
PROBABILISTIC ESTIMATION
THEORETICAL DATA