LOW-TEMPERATURE MECHANICAL-PROPERTIES OF STEELS CONTAINING HIGH-CONCENTRATIONS OF HELIUM

Results of tensile tests and hardness measurements in the temperature range 25-400 degrees C are reported for ferritic-martensitic steels an d s.a. 316 L austenitic steel. Helium concentrations up to 1 at.% have been introduced into these materials by alpha-particle (0-25 Merit im plantation and He/Fe dual-beam (15/300 keV) irradiation. respectively. III the latter case displacement damage up to 50 dpa was produced sim ultaneously with the introduction of He. From a preliminary analysis o f the results and a comparison with earlier data it may be concluded t hat for temperatures up to at least 400 degrees C the observed hardeni ng is dominated by displacement damage. Only for very high helium conc entrations around 1 at.% a moderate further increase of hardness is fo und, indicating that helium does not have a drastic effect on the mech anical properties of the investigated alloys. (C) 1997 Elsevier Scienc e B.V.