The creeping damage presumption manner which features that

摘要

PROBLEM TO BE SOLVED: To provide a method capable of estimating accurately a creep damage of a copper (Cu)-added austenitic steel heat transfer tube.;SOLUTION: In this method, the creep damage is estimated accurately by observing the metallographic structure of a sample tube extracted from an actual machine by a transmission electron microscope, and by measuring the density of black spots on a strain field generated by deposition of a Cu-enriched phase by the following methods. (1) The metallographic structure of the sample tube is observed by the transmission electron microscope, and the density of the black spots on the strain field generated by deposition of the Cu-enriched phase is measured, and a creep damage rate is determined from a chart determined beforehand for showing the relation between the density of the black spots and the creep damage rate, to thereby estimate the creep damage. (2) The density of the black spots on the strain field is measured, and the progression degree of the creep damage is estimated by whether the density of the black spots is below a fixed value determined beforehand or not. (3) The area ratio occupied in a unit visual field area by the black spots on the strain field or the number of the spots in the unit visual field is measured, and the creep damage is estimated by whether the result is below a fixed value or not.;COPYRIGHT: (C)2003,JPO