Tensile properties of V-Cr-Ti alloys after exposure in helium and low-partial-pressure oxygen environments

A test program is in progress to evaluate the effect of oxygen at low pO2 on the tensile properties of V-(4-5)wt% Cr-(4-5)wt% Ti alloys. Some of the tensile specimens were precharged with oxygen at low pO2 at 500 degrees C and reannealed in vacuum at 500 degrees C in environments with various pO2 levels and subsequently tensile tested at room temperature. The preliminary results indicate that both approaches are appropriate for evaluating the effect of oxygen uptake on the tensile properties of the alloys. The data showed that in the relatively short-time tests conducted thus far, the maximum engineering stress slightly increased after oxygen exposure but the uniform and total elongation values exhibited significant decrease after exposure in oxygen-containing environments. The data for a specimen exposed to a helium environment were similar to those obtained in low pO2 environments