Torsional joints of stainless steel bonded with an epoxy-imide high-temperature structural adhesive have been tested in creep in the temperature range 180-245 degrees C. After primary creep, in which creep rate decreases, there follows a period of secondary, or stationary, creep at constant creep rate, before failure occurs abruptly or after a period of tertiary creep with increasing deformation rate. Secondary creep has been analysed and two types of behaviour have been observed, each being attributed to a predominant mechanism: alpha at high stress and/or temperature, and beta at low stress and/or temperature. Using reaction rate theory, a theoretical model has been developed in which the distinction between the processes is associated with a stress-activated transition temperature, closely related to the glass transition temperature. This transition evolves with creep. Creep in nitrogen is shown to be somewhat less marked than in air, suggesting synergy between stress and oxidation. Creep and ensuing degradation are essentially physical phenomena, yet the presence of oxygen can clearly exacerbate both.