Indentation based life assessment for boiler tubes of fossil power plants

AbstractBoiler tubes of fossil power plant are used in high temperature and high pressure operating conditions are required to resist creep damage, fatigue cracking, and corrosion damages. Especially, X20CrMoV12.1 (12%Cr) steel has been widely used for superheater and reheater tubes of power plants due to its improved creep strength and higher oxidation resistance. Long-term service at the elevated temperature causes deterioration of mechanical property of materials as a result of changes in micro structure. Thus the accurate knowledge of degradation or life consumption level considering strength decrease is necessary to make a plan for the effective operation and maintenance. In this paper, some material properties such as yield strength, tensile strength, of X20CrMoV12.1 steel tubes were experimentally evaluated by portable indentation tester. Also damage evolution parameters of continuum damage models are modified to determine remaining life of boiler tubes. Which methodology was developed for the in-situ experiment for plant facilities