Hydrogen Embrittlement of Reactor Pressure Vessel Steels


Hydrogen Embrittlement of Reactor Pressure Vessel Steels

Uhlemann, M.; Müller, G.; Böhmert, J.

The embrittlement of reactor pressure vessel steels is mainly effected by the neutron field. However, recently results have pointed out an additional or coupled effect of hydrogen. The aim was to investigate the influence of hydrogen on mechanical behaviour of different unirradiated reactor pressure vessel steels up to the working temperature in dependence on cathodic hydrogen charging conditions in correlation to chemical composition, microstructure, and hydrogen diffusivity and solubility. Diffusivity and solubility of hydrogen were determined by means of permeation measurements, thermodesorption measurements, and hot extraction. Small differences are mainly caused by the chemical composition of the steels. Higher copper and phosphorus contents do not yield an expected higher hydrogen uptake of the unirradiated steels. The mechanical properties were determined by slow tensile tests up to 250°C with simultaneously hydrogen charging in simulated reactor pressure water dependent on strain rate and charging conditions, and by impact tensile tests. The results of the mechanical tests and the corresponding fractographic analysis showed hardly an effect of hydrogen and no significant differences of the steels under the applied charging conditions. The loss of ductility decreases with increasing strain rate and increasing temperature. These results are the staring point for further investigations on irradiated samples.

Keywords: diffusivity; hydrogen; embrittlement; mechanical properties; reactor pressure vessel steels; solubility

  • Lecture (Conference)
    EDEM 2003 - International Conference on Environmental Degradation of Engineering Materials, Bordeaux, 29.06-02.07.2003, Vollversion auf CD
  • Contribution to proceedings
    EDEM 2003 - International Conference on Environmental Degradation of Engineering Materials, Bordeaux, 29.06-02.07.2003, Vollversion auf CD

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Publ.-Id: 5261