Comparative evaluation of creep response of X20 and P91 steam piping networks in operation

Abstract

The geometrical increase in the demand for electrical energy has posed serious pressure on the power generation components such as the steam pipes due to the consequential increase in the operating parameters such as temperature and pressure. This increment in operating parameters tends to limit the useful life of these pipes. Thus, high creep resistant materials such as X20 CrMoV12-1 and P91 (9Cr-1Mo) are used to manufacture steam pipes. In this paper, the creep behaviour of X20 CrMoV12-1 and P91 (9Cr-1Mo) steam piping network subjected to typical operating condition was determined via a finite element analysis code, Abaqus CAE/2017 alongside fe-safe/Turbolife software, and their results were compared. The maximum creep stress, strain rate, creep damage and worst creep life in both piping materials were developed on the intrados of the elbow, with P91 steam pipe having higher useful creep life. Furthermore, a good correlation was achieved between the result of the analytically calculated and numerically simulated creep rate at the straight section of the piping networks.