Application of cyclic polarization method in selecting hardfacing materials for fast reactor valves with regard to their corrosion resistance in decontamination solutions

The electrochemical evaluation is made of the resistance of overlay and spray alloys used for fast reactor valves to the corrosion effects of decontamination solutions. Selected testing materials included AISI type steels, 316L steels and various other materials of the Stellite, Colmonoy and Real type materials and WC based metal ceramics. Measurements showed that for the electrochemical evaluation of the said alloys it will be best to use the method of cyclic polarization of tested materials in a 5% solution of HNO3 + 0.3% KMNO4 at a temperature of 20 degC. Briefly discussed are the measurement results that show that both the chemical composition and the technology of the preparation of the overlay or spray material are significantly affected by the corrosion stability of the material in decontamination solutions. Proceeding from the results of the measurements it will be possible to concentrate on a substantially smaller range of materials and to devote attention to optimizing the technology of their preparation. (Z.M.). 1 fig., 1 tab., 6 refs