Fatigue Damage Evaluation in Heat Transfer Tubes of an Orve By Measuring Dislocation Cell-Wall Thickness Developpement D'Une Technique De Diagnose Du Degre D'Affaiblissement Par Fatigue Des Tubes De Transfert Thermique Dans Les Orv Par La Mesure D'Ep

摘要

For heat transfer tubes of an ORV which suffer repeated thermal stress during operation, evaluation of fatigue damage is demanded intensely, because there are many devices which will reach to the designed lives in the near future. After fatigue crack initiation, damage evaluation has been used in practice using fracture mechanics. Howeve,r prior to crack initiation, evaluation of ftigue damage and estimation of remaining life have not been put in practical use successfully yet.