LIFE EVALUATION METHOD AND LIFE EVALUATION DEVICE OF AUSTENITIC STAINLESS STEEL

摘要

PROBLEM TO BE SOLVED: To provide a life evaluation method and a life evaluation device that can accurately evaluate a life of austenitic stainless steel by evaluating an anterior half of the life by an area ratio of a &sgr; phase precipitated on a surface and by evaluating a posterior half of the life by an area ratio of voids generated on the surface.SOLUTION: A life evaluation method of austenitic stainless steel comprises the steps of: calculating a &sgr; phase area ratio of a &sgr; phase precipitated on a surface of an inspection object portion; calculating void number density of voids generated on the surface of the inspection object portion; determining whether or not the &sgr; phase area ratio of the inspection object portion is a first threshold value &sgr;th or less; calculating a corresponding creep life consumption rate by applying the &sgr; phase area ratio to a curve part of an A region of a third relational expression when the &sgr; phase area ratio of the inspection object portion is the first threshold value &sgr;th or less; and, on the other hand, calculating the corresponding creep life consumption rate by applying the void number density to a linear part of a B region of the third relational expression when the &sgr; phase area ratio of the inspection object portion is the first threshold value &sgr;th or more.