High temperature behaviour of materials and components under creep conditions

This paper describes some recent work on the stress analyses and failure prediction of some typical pressurised high temperature components under creep conditions, including plain pipes, pipe bends, branch connections and welds etc, in the main steam pipework of power plant. The materials used are typically low alloy ferritic CrMoV steels. Experimental creep testing methods, and the procedures used for generating the material properties in creep and damage constitutive equations, are briefly described. Some typical numerical results are presented to illustrate the main characteristics of the behaviour of these components and to demonstrate the effects of geometry, material properties and loading modes on stress distributions and failure life predictions. The emphasis of the paper is on welded components.