Extrapolation of creep strain data for pure copper

High-temperature plants operating in the creep regime are typically designed for a lifetime of 100 000 to 250 000 h. To obtain design data, short time data must be extrapolated to the lifetimes of technical interest. In the present paper a new method for the simultaneous extrapolation of creep strain and rupture data is proposed. This approach has the advantage that it improves the statistical basis for the evaluation and makes it possible to avoid physically impossible results frequently obtained if creep strain data are analyzed separately. The method has successfully been applied to phosphorus-alloyed pure copper.