Hydrogen influence on zirconium alloy Zr-0.5Nb mechanical characteristics at ambient and elevated temperatures

Abstract

This paper deals with the investigation of the in-fluence of hydrogen concentration on zirconium alloy Zr-2.5Nb (TMT-2) mechanical characteristics at various oper-ating regimes, which are related to temperature variationfrom normal to elevated up to 300ºC. Tensile specimens, which were cut off from the reactor fuel channel tube free and hydrogen saturated at concentration levels from 52 up to 140 ppm were tested in order to evaluate the influence of hydrogen ingress on mechanical properties of the alloy. Specimens made from hydrogen free alloy were tested at 20, 150 and 300ºC temperatures, while hydrogen saturated specimens were tested at 20, 170, 200 and 300ºC. Results of the investigation has shown that at temperature increase mechanical characteristics of strength decrease and reduc-tion of are increase. Saturation with hydrogen has stronger influence on mechanical characteristics only at 20-170ºC and increases decreasing temperature.