Embrittlement of Cr-Mo steels after low fluence irradiation in HFIR

Technical Report · Sat Apr 01 04:00:00 EST 1995

DOI:https://doi.org/10.2172/114930· OSTI ID:114930

Klueh, R. L.; Alexander, D. J.

The goal of this work is the determination of the possible effect of the simultaneous formation of helium and displacement damage during irradiation on the Charpy impact behavior. Subsize Charpy impact specimens of 9Cr-1MoVNb (modified 9Cr-1Mo) and 12Cr-1MoVW (Sandvik HT9) steels and 12Cr-1MoVW with 2%Ni (12Cr-1MOVW-2Ni) were irradiated in the High Flux Isotope Reactor (HFIR) at 300 and 400{degree}C to damage levels up to 2.5 dpa. The objective was to study the effect of the simultaneous formation of displacement damage and transmutation helium on impact toghness. Despite the low fluence relative to previous irradiations of these steels, significant increases in the ductile-brittle transition temperature (DBTT) occurred. The 12Cr-1MoVW-2Ni steel irradiated at 400{degree}C had the largest increase in DBTT and displayed indications of intergranular fracture. A mechanism is proposed to explain how helium can affect the fracture behaviour of this latter steel in the present tests, and how it affected all three steels in previous experiments, where the steels were irradiated to higher fluences.

• Research Organization: Oak Ridge National Lab., TN (United States)
• OSTI ID: 114930
• Report Number(s): DOE/ER--0313/17; ON: DE95013663
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ATOMIC DISPLACEMENTS
CHARPY TEST
DUCTILE-BRITTLE TRANSITIONS
FERRITIC STEELS
HELIUM EMBRITTLEMENT
IRRADIATION
MARTENSITIC STEELS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NIOBIUM ALLOYS
PHYSICAL RADIATION EFFECTS
PROGRESS REPORT
TUNGSTEN ALLOYS
VANADIUM ALLOYS