The Constant Load Creep Testing machine with environmental chamber and crack monitoring system will be used to study the effect of various gaseous environments on sustained load crack initiation and crack propagation at high temperatures in a variety of metals, alloys, and advanced materials. this work will expand previous studies of intergranular penetration of aggressive gaseous species to study how monotonic stress, and complex stress and strain fields, influence the kinetics of penetration. The role of this diffusion, and the concentration of embrittling elements in advance of a crack, in controlling high temperature time-dependent fracture will be explored in detail.
