The understanding of time dependent crack propagation processes occupies a central place in the study of fracture. It also encompasses a wide range of conditions: failure under sustained loading in a corrosive environment, fracture under cyclic loading in non-degrading and in corrosive environment, and rupture at high temperature. This list covers probably 90% of the failures that occur in engineering practice. The process of time dependent fracture is controlled by the physics of atomic interaction changes; it is strongly influenced by the micro­ structure; and affected by the interaction of the material with the mechanical (load, displacement), the thermal (temperature), and the chemical or radiation environment. To be able to control crack propagation the development of testing methods and the understanding of the industrial environment is essential. The conference was organized in this context. A call was issued for contributions to the following topics. THERMAL ACTIVATION. Theoretical papers dealing with the modification of fracture mechanics to accommodate thermally activated processes. TIME DEPENDENT MICRO-PROCESSES. Presentations covering both the theoretical and observational aspects of creep and fatigue damage in materials whose microstructures may exert a significant influence on crack growth. INDUSTRIAL APPLICATIONS. Submissions describing the practical application of fracture mechanics and damage tolerance analysis to the determination of useful operating lives. x ENVIRONMENTAL EFFECTS. Papers dealing with engineering materials and/or components exposed to aggressive environments, with and without temperature effects. The response was gratifying. Leading experts responded; the organizers of the conference are grateful for the large number of excellentcontributions.