DETERMINATION OF THE DISSOLUTION TEMPERATURE OF HYDRIDES BY DILATOMETRY IN AN UNIRRADIATED ZIRCONIUM ALLOY E635
The dissolution temperature of the hydrides was determined by dilatometry, based on the position of the peak on the first derivative of the relative elongation of the sample from the temperature. The object of the study was samples of an unirradiated alloy E635 with a hydrogen content of 150 -500 ppm. The samples were heated to 600 °C at a rate of 5 °C / min. The dissolution temperature of the hydrides was found to be 356±3, 398±3, and 440±3 °C at hydrogen concentrations of 150, 300, and 500 ppm, respectively. Calculated from experimental data, the enthalpy of dissolution of the hydrides is 54 kJ/mol.