The influence of certain trace elements, namely Pb, Sn, Te, Se and Tl, on the creep and stressrupture properties of Nimonic 105 was investigated at 815 °C. The work was supported by the Ministry of Defence, and was planned in close collaboration with Rolls-Royce, who advised, in particular, on the trace elements to be studied and the levels at which harmful effects on creep performance might be expected. The results obtained have confirmed that, with the exception of Sn, all the elements reduce the life to rupture and the ductility at failure when present in sufficient amount. The most deleterious impurities were Te and Pb. Stress-rupture testing with notched specimens gave a generally more sensitive indication of the presence of harmful amounts of impurity than did tests with plain specimens.
