DETERIORATION ASSESSING METHOD FOR HEAT-RESISTANT STEEL AND DETERIORATION ASSESSING METHOD FOR TURBINES

摘要

PROBLEM TO BE SOLVED: To provide a method of assessing deterioration of heat-resistant steel by non-destructively evaluating creep damages, which are thermal damages occurring to heat-resistant steel, in particular high Cr steel, and a deterioration assessing method for turbines using this method.SOLUTION: By a deterioration assessing method for heat-resistant steel, the density in unit number terms of voids having arisen in the surface of heat-resistant steel, which is the object of examination, is calculated and standardized according to the multiaxiality level of heat-resistant steel; and, on the basis of a graph prepared in advance showing the correlation between the life ratio of heat-resistant steel and the density in unit number terms of voids standardized according to the multiaxiality level, the extent of creep damages to the heat-resistant steel, which is the object of examination, is assessed by a value resulting from the standardization of the density in unit number terms of voids having arisen in the surface of heat-resistant steel, which is the object of examination, according to the multiaxiality level.