Assessment of the residual life of a pipeline bend by metallographic measurements of cavitation damage-Determination of the A-parameter

Abstract

The residual service life of the components of power plants under conditions of creep can be measured by various methods. As a rule, these methods can be classified as destructive, nondestructive, or analytical. The nondestructive method is based on the determination of the metallographic A-parameter, i.e., a quantity equal to the ratio of the number of damaged grain boundaries to the total number of boundaries in the direction of the principal normal stress. By using this method, we determine the residual service life of a pipeline bend operating at a temperature of 530°C under a stress of 100 MPa.