AbstractTraditional component design procedures consider service lifetimes to be limited by either stress or chemical attack from reactive components in the fluid working environment. However, these processes are often coupled; stress can affect the rate of environmental attack and vice versa. The synergy resulting from this coupling is frequently detrimental with regard to service performance, and creep lifetimes, for example, may be reduced dramatically; the paper reviews the evidence and identifies the underlying mechanisms. Physically based equation sets for coupled creep and environmental attack are also presented and some of their predictions are compared favourably with data published previously.MST/1126