Creep-Fatigue Crack Growth in Power Plant Steels

摘要

An important consideration in the characterisation of creep-fatigue crack growth rates and the defect assessment of high temperature components is the size of pre-existing or service-induced flaws relative to the dimensions of associated cyclic plastic zones. In particular, long cracks are those whose size exceeds r (p) and short cracks are those whose size is less than r (p), and the way in which their propagation is analytically represented can differ depending on the form of loading and the respective contributions of creep and fatigue damage accumulation. Examples are given for a number of power plant steels. There are now published procedures for the assessment of structural integrity in high temperature components subject to creep-fatigue loading, and guidance on how to generate the necessary properties for their implementation, and these are reviewed.