EVALUATION METHOD FOR CREEP LIFE OF TEMPERED MARTENSITE HEAT-RESISTING STEEL

摘要

PROBLEM TO BE SOLVED: To obtain an evaluation method for the creep life of tempered martensite heat-resisting steel, in which the creep life of a high-temperature apparatus material being used at a high temperature can be evaluated by a simple operation, with a small material sampling amount, in a short time, and with good accuracy. SOLUTION: In the evaluation method for the creep life of tempered martensite heat-resisting steel, which is used for a high-temperature apparatus and which contains 9 to 12wt.% of Cr, a test piece is sampled from a part, to be investigated, in the high-temperature apparatus being used, the subgrain size of its material is measured by using the test piece, a creep strain is calculated on the basis of a previously created relationship diagram between the subgrain size and the magnitude of the creep strain, and a creep-life consumption rate is calculated on the basis of a previously created relationship diagram between the magnitude of the creep strain and a creep-life consumption rate.