STP782

    Effects of Neutron Irradiation and Temperature on High Strain Rate Behaviour of Reactor Pressure Vessel Steel

    Published: Jan 1982


      Format Pages Price  
    PDF (188K) 13 $25   ADD TO CART
    Complete Source PDF (19M) 13 $77   ADD TO CART


    Abstract

    This paper describes the results of an investigation of the influence of neutron irradiation on mechanical properties of a reactor pressure vessel steel at high strain rates ˙ɛ ≈ (103 to 104)s−1 produced by means of the Hopkinson split pressure bar technique (HSPBT). Our steel with chemical composition 0.18% C, 1.22% Mn, 0.012% P, 0.016% S, 0.17% Cr, 0.33% Ni, 0.055% Al, 0.028% Ti was irradiated by fast neutrons to an exposure of 1.35 . 1023 (n)m−2. The extensive dynamic measurements performed in the temperature range of (90 + 573) °K are analysed in terms of state equation for viscoplastic flow. It is shown that neutron irradiation shifts the transition between thermally activated and viscous dislocation damping mechanism of plastic deformation to the higher strain rates. Particular attention is paid to the comparison of the influence of neutron irradiation and strain aging.

    The experimental data obtained indicate that plastic strain rate ˙ɛ is a linear function of dynamic over stress δfl2 − 1, ˙ɛ = = γ (δfl2 − 1) + ˙ɛ2 where γ is viscosity coefficient, δfl denotes flow stress and δ2, ˙ɛ2 are stress and strain rate respectively which control the transition between termally activated process and viscous damping mechanism. It appears that δ2 and ˙ɛ2 are strongly influenced by neutron irradiation and strain aging although γ is nearly independent of both.

    Keywords:

    pressure vessel steel, neutron irradiation, dynamic mechanical properties, strain aging, Hopkinson split pressure bar technique, strain rate, embrittlement, brittle-ductile transition temperature


    Author Information:

    Buchar, J
    Research engineer, manager, and application engineer, Department of Brittle Fracture, Institute of Physical Metallurgy, Czechoslovak Academy of Sciences, Žižkova,

    Bílek, Z
    Research engineer, manager, and application engineer, Department of Brittle Fracture, Institute of Physical Metallurgy, Czechoslovak Academy of Sciences, Žižkova,

    Dušek, F
    Research engineer, manager, and application engineer, Department of Brittle Fracture, Institute of Physical Metallurgy, Czechoslovak Academy of Sciences, Žižkova,


    Paper ID: STP34365S

    Committee/Subcommittee: E10.07

    DOI: 10.1520/STP34365S


    CrossRef ASTM International is a member of CrossRef.