Influence of helium and hydrogen on the embrittlement of construction materials with fcc- and bcc-lattices

An attempt of critical comparative analysis of helium embrittlement (HE) tendencies in austenite alloy with high content of nickel X20H45 (fcc) and ferrite steel X13M1 (bcc) was made. It was shown that a strong influence of the high-temperature deformation velocity on HE in austenite materials exists and a noticeable intensification of HE was detected when the deformation velocity is lowered. Influence of helium on high-temperature mechanical properties of austenite alloy and ferrite steel in general is the same. The discovered effect of HE sharp increase in case of hydrogen adding requires a further study. 13 refs.; 7 figs. (J.P.)