CREEP DAMAGE EVALUATION METHOD OF THERMAL SPRAY COATED TUBE OF BOILER FURNACE

摘要

PROBLEM TO BE SOLVED: To provide a creep damage evaluation method of a thermal spray coated tube of a boiler furnace, which can predict a position and shape of an axis-direction crack of a header and also a damage level of the header without removing a sprayed coating and receiving an influence on a circumferential-direction crack existing in the sprayed coating, and which can thereby significantly reduce points requiring the removal (peeling operation) of the sprayed coating and polishing.;SOLUTION: A magnetic-particle test (MT) is performed on a surface of a sprayed coating 3 so that a distribution of magnetic particles is detected, and the presence of an axis-direction crack 4 existing in the sprayed coating 3 is evaluated from the distribution of the magnetic particles. When the axis-direction crack 4 is present, a strain of the sprayed coating 3 at a position of the crack is measured, and a strain of a header material is predicted from the measurement. When the prediction value is less than a threshold, the thermal spray coated tube is continuously used without repair of the cracked point.;COPYRIGHT: (C)2013,JPO&INPIT