Creep Rupture of Ductile Materials Subjected to Strain Hardening or Time Hardening Creep.

摘要

An analysis of creep rupture of ductile materials subjected to strain hardening creep is presented. The analysis is similar to an earlier one by Hoff, but is based on a different generalization of the primary creep rate relation. Both approaches are then extended to time hardening creep. Simple approximate formulae for critical times are presented and the results of both approaches for the two types of creep are compared. Correlation with experimental data for some aluminum-copper, aluminum-magnesium and aluminum-zinc alloys shows fairly good agreement of rupture times for these very ductile materials. However, attempted correlation with data for other materials which do not exhibit such prominent ductility indicates that the basic assumption of the analysis, that creep rupture is caused primarily by a process of reduction of area, holds only for very ductile materials. (Author)